Jump to content

The Marshall Star for October 9, 2024


NASA

Recommended Posts

  • Publishers
30 Min Read

The Marshall Star for October 9, 2024

Category 5 Hurricane Milton, packing winds of 175 miles per hour, is viewed in the Gulf of Mexico from the space station as it orbited overhead.

Marshall Lends Insight, Expertise to Auburn Aerospace Industry Day Event

By Rick Smith

Nearly 500 students and faculty of Auburn University gathered on campus Sept. 30-Oct. 2 to hear lectures from leading NASA propulsion and engineering experts and to talk careers goals and opportunities with representatives of the U.S. space program and various aerospace industry firms.

The Aerospace Industry Day event, exclusively focused on careers supporting rocketry and space exploration, was the first of its kind at Auburn. University spokespersons said they hope to make it an annual expo – and team members from NASA’s Marshall Space Flight Center helped ensure the kickoff was a success.

Heather Haney, center, test and verification subsystem manager in the Space Launch System Program Office at NASA’s Marshall Space Flight Center, discusses aerospace career options with Auburn University faculty and students during Aerospace Industry Day events.
Heather Haney, center, test and verification subsystem manager in the Space Launch System Program Office at NASA’s Marshall Space Flight Center, discusses aerospace career options with Auburn University faculty and students during Aerospace Industry Day events.
Photo courtesy of Auburn University/John Sluis

“The event marked a significant milestone for our organization and the university as a whole,” said Austin Miranda, an Auburn aerospace engineering undergraduate and president of Auburn’s chapter of the American Institute of Aeronautics and Astronautics. “We deeply appreciate NASA’s participation, which significantly enriched the experience for our attendees.”

Marshall managers and engineers in the Space Launch System and Human Landing System programs, the Engineering Directorate, and the Space Nuclear Propulsion Office presented guest lectures, staffed exhibit booths, and met informally with students. The event also included a pair of intensive focus sessions on propulsion engineering, face-to-face networking opportunities between students and NASA and industry leaders, and a career fair with Marshall, the U.S. Space & Rocket Center, and more than a dozen leading aerospace industry companies.

“As an Auburn alum, it’s always great to be able to return to the plains and engage in activities on campus,” said Josh Whitehead, associate manager of the SLS Stages Element at Marshall. “I was impressed not only with the outstanding faculty who engaged from multiple engineering departments, but also with the engineering students who asked informed, insightful questions about NASA, our missions, and the new technologies we are developing to enable exploration of space.”

Mike Houts, nuclear research manager for NASA’s Space Nuclear Propulsion Office at Marshall, also was struck by students’ enthusiasm.

“The students’ depth of interest and understanding was impressive,” he said. “Many of them stayed to talk long after events were officially over, and several have already followed up by email. I foresee lots of ‘win-win’ potential moving forward.”

Alex Ifkovits, left, a Marshall liquid engine systems engineer, talks with an Auburn University student during Aerospace Industry Day events, which ran Sept. 30-Oct. 2. The event was the first of its kind at Auburn and is expected to become a perennial mainstay for the engineering curriculum.
Alex Ifkovits, left, a Marshall liquid engine systems engineer, talks with an Auburn University student during Aerospace Industry Day events, which ran Sept. 30-Oct. 2. The event was the first of its kind at Auburn and is expected to become a perennial mainstay for the engineering curriculum.
Photo courtesy of Auburn University/John Sluis

Among the aerospace industry participants were representatives from the U.S. Missile Defense Agency, Gulfstream Aerospace Corp., Jacobs Technology, Lockheed Martin, Relativity Space, Reliable Microsystems, RTX subsidiaries Pratt & Whitney and UTC Aerospace Systems, and Technology Service Corp. 

“Everyone was impressed with the level of knowledge and interest from Auburn students, many of whom waited in long lines to ask questions and talk about career opportunities,” said Heather Haney, SLS Program test and verification subsystem manager. “NASA has a great history of collaborating with Auburn to support our nation’s space program, and that was reflected by the excitement on so many faces during the event.”

Auburn has contributed to a number of key Marshall endeavors in recent years, including support for Marshall’s RAMPT (Rapid Analysis and Manufacturing Propulsion Technology) project, refining a variety of additive manufacturing processes, and for a new laser-ablation technology study to develop multi-material 3D printers for use in microgravity. The latter is set to begin testing in spring 2025. Additive manufacturing research at Auburn was pivotal to development of NASA’s 2024 Invention of the Year, an innovative rocket engine thrust chamber liner and fabrication method. Auburn students also are perennial contenders in annual NASA STEM events, including the NASA Human Exploration Rover Challenge and the Student Launch rocketry competition.

The Aerospace Industry Day event was hosted by Auburn’s Office of Career Development and the Samuel Ginn College of Engineering.

Smith, an Aeyon employee, supports the Marshall Office of Communications.

› Back to Top

NASA, SpaceX Secure Europa Clipper Ahead of Hurricane

NASA and SpaceX are standing down from the Oct. 10 launch attempt of the agency’s Europa Clipper mission due to anticipated hurricane conditions in the area.

Hurricane Milton is expected to move east to the Space Coast after making landfall on Florida’s west coast. High winds and heavy rain are expected in the Cape Canaveral and Merritt Island regions on Florida’s east coast. Launch teams have secured NASA’s Europa Clipper spacecraft in SpaceX’s hangar at Launch Complex 39A at the agency’s Kennedy Space Center ahead of the severe weather, and the center began hurricane preparations Oct. 6.

ksc-20241002-ph-jbs02.png?w=1200
Technicians encapsulated NASA’s Europa Clipper spacecraft inside payload fairings Oct. 2 in the Payload Hazardous Servicing Facility at the agency’s Kennedy Space Center.
NASA/Ben Smegelsky

“The safety of launch team personnel is our highest priority, and all precautions will be taken to protect the Europa Clipper spacecraft,” said Tim Dunn, senior launch director at NASA’s Launch Services Program.

On Oct. 4, workers transported NASA’s Europa Clipper spacecraft from the Payload Hazardous Servicing Facility at Kennedy to the SpaceX Falcon Heavy rocket in the hangar as part of final launch preparations ahead of its journey to Jupiter’s icy moon. While Europa Clipper’s launch period opens Oct. 10, the window provides launch opportunities until Nov. 6.

Once the storm passes, recovery teams will assess the safety of the spaceport before personnel return to work. Then launch teams will assess the launch processing facilities for damage from the storm.

“Once we have the ‘all-clear’ followed by facility assessment and any recovery actions, we will determine the next launch opportunity for this NASA flagship mission,” Dunn said.

Managed by Caltech in Pasadena, California, NASA’s Jet Propulsion Laboratory (JPL) leads the development of the Europa Clipper mission in partnership with the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, for NASA’s Science Mission Directorate. The main spacecraft body was designed by APL in collaboration with JPL and NASA’s Goddard Space Flight Center. The Planetary Missions Program Office at NASA’s Marshall Space Flight Center executes program management of the Europa Clipper mission. NASA’s Launch Services Program, based at Kennedy, manages the launch service for the Europa Clipper spacecraft.

› Back to Top

Crew Departure Preps Continue Aboard Space Station

The seven NASA astronauts aboard the International Space Station relaxed and took a break Oct. 8 before the SpaceX Crew-8 mission leaves. Mission managers are monitoring weather conditions off the coast of Florida with Hurricane Milton.

Expedition 72 flight engineers Matthew DominickMike Barratt, and Jeanette Epps of NASA and Alexander Grebenkin from Roscosmos are now targeting departure from the orbital outpost aboard the SpaceX Dragon Endeavour spacecraft for no earlier than 2:05 a.m. CDT on Oct. 13, pending weather. The Commercial Crew Program (CCP) crew is scheduled to call down to Mission Control Center for farewell remarks Oct. 10 at 8:15 a.m. Watch live coverage of both events on NASA+. Learn how to watch NASA content through a variety of platforms, including social media.

Category 5 Hurricane Milton, packing winds of 175 miles per hour, is viewed in the Gulf of Mexico from the space station as it orbited overhead.
Category 5 Hurricane Milton, packing winds of 175 miles per hour, is viewed in the Gulf of Mexico from the space station as it orbited overhead.
NASA

Space biology and physics were the focus of research operations for the Expedition 72 crew Oct. 7. NASA flight engineer Nick Hague worked in the Columbus laboratory module swapping filters inside the BioLab’s incubator. BioLab supports the observation of microbes, cells, tissue cultures and more to understand the effects of weightlessness and radiation on organisms. NASA flight engineer Don Pettit set up a laptop computer on the Cell Biology Experiment Facility, a research incubator with an artificial gravity generator, located in the Kibo laboratory module.

Station Commander Suni Williams explored space physics mixing gel samples and observing with a fluorescence microscope how particles of different sizes gel and coarsen. Results are expected to benefit the medicine, food, and cosmetic industries. NASA astronaut Butch Wilmore, who has been aboard the station with Williams since June 6, trained to operate advanced life support gear installed in the Microgravity Science Glovebox for a different space physics experiment then relaxed the rest of the day.

The Huntsville Operations Support Center (HOSC) at NASA’s Marshall Space Flight Center provides engineering and mission operations support for the space station, the CCP, and Artemis missions, as well as science and technology demonstration missions. The Payload Operations Integration Center within HOSC operates, plans, and coordinates the science experiments onboard the space station 365 days a year, 24 hours a day.

› Back to Top

Dave Reynolds Named Manager of Space Launch System Booster Office

Dave Reynolds has been named to the Senior Executive Service position of manager of the Space Launch System (SLS) Booster Office at NASA’s Marshall Space Flight Center, effective immediately. In his role, Reynolds is responsible for the design, development, and flight of the solid rocket boosters for the SLS rocket, NASA’s deep-space flagship rocket, designed for a new era of science and exploration.

Dave Reynolds
Dave Reynolds has been named to the Senior Executive Service position of manager of the Space Launch System (SLS) Booster Office at NASA’s Marshall Space Flight Center.
NASA/Danielle Burleson

Reynolds began his NASA career in Marshall’s propulsion systems department in 2004 as a rocket engines component designer. Since 2020, Reynolds has served as the deputy program manager for the SLS Boosters Office. In this role, he was responsible for the execution of two major contracts with a combined value of $7.6 billion. He also served as an alternate to the manager for overseeing the performance, budget, schedule, and discretionary spending for developing, fabricating, and flying the SLS Boosters. Reynolds supervised a team of 31 civil servants and contractors and acted as the representative for the booster element in key SLS program reviews decision boards, milestones, and budget risk assessments.

Reynolds’ previous roles include leading the development program for the SLS Booster Obsolescence and Life Extension effort starting in 2016, officially being selected as the development program manager in 2019. In this role he was responsible for creating the strategic plan and initiating the early development phases for the SLS Block II Booster. He also served as a SLS Booster subsystem manager from 2013-2019 where he was responsible for the management of the SLS motor cases, igniters, and small motors.

From 2012-2013, Reynolds participated in a temporary rotational assignment with the Defense Intelligence Agency’s Missile and Space Intelligence Center where he acted as the NASA liaison as a propulsion subject matter expert and supported military intelligence assessments of foreign weapon systems. From 2002-2004, Reynolds was a design engineer at the Naval Air Warfare Center Weapons Division at China Lake, California, where he served as a propulsion designer specializing in the design, fabrication, and testing of U.S. Navy weapons propulsion systems.

Reynolds holds a Bachelor of Science degree in chemical engineering from Brigham Young University and a Master of Business Administration and Management from the University of Alabama in Huntsville. He holds two patents for additive manufacturing technologies and has received numerous NASA awards including the Outstanding Leadership Medal, the Exceptional Achievement Medal, and the Silver Snoopy.

› Back to Top

NASA Announces Teams to Compete in International Rover Challenge

By Wayne Smith

NASA has selected 75 student teams to begin an engineering design challenge to build rovers that will compete next spring at the U.S. Space and Rocket Center near the agency’s Marshall Space Flight Center. The competition is one of the agency’s Artemis Student Challenges, encouraging students to pursue degrees and careers in science, technology, engineering, and mathematics (STEM).

Two students from Team Instituto Tecnologico de Santo Domingo from Santo Domingo, Dominican Republic, pedal their human-powered rover through the 2024 Human Exploration Rover Challenge course. Their teammates cheer them on from outside of the course.
A team competes in the 2024 Human Exploration Rover Challenge as supporters cheer them on.
NASA

Recognized as NASA’s leading international student challenge, the 31st annual Human Exploration Rover Challenge (HERC) aims to put competitors in the mindset of NASA’s Artemis campaign as they pitch an engineering design for a lunar terrain vehicle which simulates astronauts piloting a vehicle, exploring the lunar surface while overcoming various obstacles.

Participating teams represent 35 colleges and universities, 38 high schools, and two middle schools from 20 states, Puerto Rico, and 16 other nations from around the world. The 31st annual Human Exploration Rover Challenge (HERC) is scheduled to begin on April 11, 2025. The challenge is managed by NASA’s Southeast Regional Office of STEM Engagement at Marshall.

Following a 2024 competition that garnered international attention, NASA expanded the challenge to include a remote-control division, Remote-Operated Vehicular Research, and invited middle school students to participate. The 2025 HERC Handbook includes guidelines for the new remote-control division and updates for the human-powered division.

NASA’s Artemis Student Challenges reflects the goals of the Artemis campaign, which seeks to land the first woman and first person of color on the Moon while establishing a long-term presence for science and exploration.

More than 1,000 students with 72 teams from around the world participated in the 2024 challenge as HERC celebrated its 30th anniversary as a NASA competition. Since its inception in 1994, more than 15,000 students have participated in HERC – with many former students now working at NASA, or within the aerospace industry. 

Smith, a Media Fusion employee and the Marshall Star editor, supports the Marshall Office of Communications.

› Back to Top

Agency Selects Teams for 2025 Student Launch Challenge

By Wayne Smith

NASA has selected 71 teams from across the U.S. to participate in its 25th annual Student Launch Challenge, one of the agency’s Artemis Student Challenges. The competition is aimed at inspiring Artemis Generation students to explore science, technology, engineering, and math (STEM) for the benefit of humanity.

As part of the challenge, teams will design, build, and fly a high-powered amateur rocket and scientific payload. They also must meet documentation milestones and undergo detailed reviews throughout the school year.

Students raise their hands in celebration and cheer after a successful launch of their vehicle in the 2024 Student Launch competition.
Students celebrate after a successful performance in the 2024 Student Launch competition at Bragg Farms in Toney, Alabama.
NASA

The nine-month-long challenge will culminate with on-site events starting on April 30, 2025. Final launches are scheduled for May 3, at Bragg Farms in Toney, Alabama, just minutes north of NASA’s Marshall Space Flight Center. Teams are not required to travel for their final launch, having the option to launch from a qualified site. Details are outlined in the Student Launch Handbook.

Each year, NASA updates the university payload challenge to reflect current scientific and exploration missions. For the 2025 season, the payload challenge will again take inspiration from the Artemis missions, which seek to land the first woman and first person of color on the Moon, and pave the way for future human exploration of Mars.

As Student Launch celebrates its 25th anniversary, the payload challenge will include reports from STEMnauts, non-living objects representing astronauts. The STEMnaut crew must relay real-time data to the student team’s mission control via radio frequency, simulating the communication that will be required when the Artemis crew achieves its lunar landing.

University and college teams are required to meet the 2025 payload requirements set by NASA, but middle and high school teams have the option to tackle the same challenge or design their own payload experiment.

Student teams will undergo detailed reviews by NASA personnel to ensure the safety and feasibility of their rocket and payload designs. The team closest to their target will win the Altitude Award, one of multiple awards presented to teams at the end of the competition. Other awards include overall winner, vehicle design, experiment design, and social media presence.

In addition to the engineering and science objectives of the challenge, students must also participate in outreach efforts such as engaging with local schools and maintaining active social media accounts. Student Launch is an all-encompassing challenge and aims to prepare the next generation for the professional world of space exploration.

The Student Launch Challenge is managed by Marshall’s Office of STEM Engagement (OSTEM). Additional funding and support are provided by NASA’s OSTEM via the Next Gen STEM project, NASA’s Space Operations Mission Directorate, Northrup Grumman, National Space Club Huntsville, American Institute of Aeronautics and Astronautics, National Association of Rocketry, Relativity Space, and Bastion Technologies.

Smith, a Media Fusion employee and the Marshall Star editor, supports the Marshall Office of Communications.

› Back to Top

NASA’s Laser Comms Demo Makes Deep Space Record, Completes First Phase

NASA’s Deep Space Optical Communications technology demonstration broke yet another record for laser communications this summer by sending a laser signal from Earth to NASA’s Psyche spacecraft about 290 million miles away. That’s the same distance between our planet and Mars when the two planets are farthest apart.

Soon after reaching that milestone on July 29, the technology demonstration concluded the first phase of its operations since launching aboard Psyche on Oct. 13, 2023.

NASA’s Psyche spacecraft is depicted receiving a laser signal from the Deep Space Optical Communications
NASA’s Psyche spacecraft is depicted receiving a laser signal from the Deep Space Optical Communications uplink ground station at JPL’s Table Mountain Facility in this artist’s concept. The DSOC experiment consists of an uplink and downlink station, plus a flight laser transceiver flying with Psyche.
NASA/JPL-Caltech

“The milestone is significant. Laser communication requires a very high level of precision, and before we launched with Psyche, we didn’t know how much performance degradation we would see at our farthest distances,” said Meera Srinivasan, the project’s operations lead at NASA’s Jet Propulsion Laboratory. “Now the techniques we use to track and point have been verified, confirming that optical communications can be a robust and transformative way to explore the solar system.”

Managed by JPL, the Deep Space Optical Communications experiment consists of a flight laser transceiver and two ground stations. Caltech’s historic 200-inch aperture Hale Telescope at Caltech’s Palomar Observatory in San Diego County, California, acts as the downlink station to which the laser transceiver sends its data from deep space. The Optical Communications Telescope Laboratory at JPL’s Table Mountain facility near Wrightwood, California, acts as the uplink station, capable of transmitting 7 kilowatts of laser power to send data to the transceiver.

By transporting data at rates up to 100 times higher than radio frequencies, lasers can enable the transmission of complex scientific information as well as high-definition imagery and video, which are needed to support humanity’s next giant leap when astronauts travel to Mars and beyond.

As for the spacecraft, Psyche remains healthy and stable, using ion propulsion to accelerate toward a metal-rich asteroid in the main asteroid belt between Mars and Jupiter.

The technology demonstration’s data is sent to and from Psyche as bits encoded in near-infrared light, which has a higher frequency than radio waves. That higher frequency enables more data to be packed into a transmission, allowing far higher rates of data transfer.

Even when Psyche was about 33 million miles away – comparable to Mars’ closest approach to Earth – the technology demonstration could transmit data at the system’s maximum rate of 267 megabits per second. That bit rate is similar to broadband internet download speeds. As the spacecraft travels farther away, the rate at which it can send and receive data is reduced, as expected.

This 45-second ultra-high-definition video was streamed via laser from deep space by NASA’s Deep Space Optical Communications technology demonstration June 24, when the Psyche spacecraft was 240 million miles from Earth.

On June 24, when Psyche was about 240 million miles from Earth – more than 2½ times the distance between our planet and the Sun – the project achieved a sustained downlink data rate of 6.25 megabits per second, with a maximum rate of 8.3 megabits per second. While this rate is significantly lower than the experiment’s maximum, it is far higher than what a radio frequency communications system using comparable power can achieve over that distance.

The goal of Deep Space Optical Communications is to demonstrate technology that can reliably transmit data at higher speeds than other space communication technologies like radio frequency systems. In seeking to achieve this goal, the project had an opportunity to test unique data sets like art and high-definition video along with engineering data from the Psyche spacecraft. For example, one downlink included digital versions of Arizona State University’s “Psyche Inspired” artwork, images of the team’s pets, and a 45-second ultra-high-definition video that spoofs television test patterns from the previous century and depicts scenes from Earth and space.

The technology demonstration beamed the first ultra-high-definition video from space, featuring a cat named Taters, from the Psyche spacecraft to Earth on Dec. 11, 2023, from 19 million miles away. (Artwork, images, and videos were uploaded to Psyche and stored in its memory before launch.)

“A key goal for the system was to prove that the data-rate reduction was proportional to the inverse square of distance,” said Abi Biswas, the technology demonstration’s project technologist at JPL. “We met that goal and transferred huge quantities of test data to and from the Psyche spacecraft via laser.” Almost 11 terabits of data have been downlinked during the first phase of the demo.

The flight transceiver is powered down and will be powered back up on Nov. 4. That activity will prove that the flight hardware can operate for at least a year.

“We’ll power on the flight laser transceiver and do a short checkout of its functionality,” said Ken Andrews, project flight operations lead at JPL. “Once that’s achieved, we can look forward to operating the transceiver at its full design capabilities during our post-conjunction phase that starts later in the year.”

This demonstration is the latest in a series of optical communication experiments funded by the Space Technology Mission Directorate’s Technology Demonstration Missions Program managed at NASA’s Marshall Space Flight Center and the agency’s SCaN (Space Communications and Navigation) program within the Space Operations Mission Directorate. Development of the flight laser transceiver is supported by MIT Lincoln Laboratory, L3 Harris, CACI, First Mode, and Controlled Dynamics Inc. Fibertek, Coherent, Caltech Optical Observatories, and Dotfast support the ground systems. Some of the technology was developed through NASA’s Small Business Innovation Research program.

Psyche is the 14th mission selected as part of NASA’s Discovery Program, which is managed by Marshall.

› Back to Top

Ancient Oort Cloud Comet to Make First Documented Pass by Earth in Mid-October

By Rick Smith

An ancient celestial traveler will make its first close pass by Earth in mid-October. Mark those calendars – because it won’t be back for another 80,000 years.

The Oort Cloud comet, called C/2023 A3 Tsuchinshan-ATLAS, was discovered in 2023, approaching the inner solar system on its highly elliptical orbit for the first time in documented human history. It was identified by observers at China’s Tsuchinshan – or “Purple Mountain” – Observatory and an ATLAS (Asteroid Terrestrial-impact Last Alert System) telescope in South Africa. The comet was officially named in honor of both observatories.

A green blur streaks across the black starry background from left to right.
Comets with long, elliptical orbits around the Sun may reach perihelion – their closest point to our star – too rarely to observe more than once in a lifetime. This comet, Lovejoy (C/2014 Q2), reached perihelion in early February 2015, and isn’t expected to do so again until 2633. Comet Tsuchinshan-ATLAS, which is expected to come within approximately 44 million miles of Earth on Oct. 12, will not enter the inner solar system again for some 80,000 years.
NASA/Damian Peach

The comet successfully made its closest transit past the Sun on Sept. 27. Scientists surmised it might well break up during that pass, its volatile and icy composition unable to withstand the intense heat of our parent star, but it survived more or less intact – and is now on track to come within approximately 44 million miles of Earth on Oct. 12.

“Comets are more fragile than people may realize, thanks to the effects of passing close to the Sun on their internal water ice and volatiles such as carbon monoxide and carbon dioxide,” said NASA astronomer Bill Cooke, who leads the Meteoroid Environment Office at NASA’s Marshall Space Flight Center. “Comet Kohoutek, which reached the inner solar system in 1973, broke up while passing too close to the Sun. Comet Ison similarly failed to survive the Sun’s intense heat and gravity during perihelion in 2013.”

Though Comet Tsuchinshan-ATLAS will be ideally positioned to view from the Southern Hemisphere, spotters above the equator should have a good chance as well. Peak visibility will occur Oct. 9-10, once the half-moon begins to move away from the comet.

Choose a dark vantage point just after full nightfall, Cooke recommended. Looking to the southwest, roughly 10 degrees above the horizon, identify the constellations of Sagittarius and Scorpio. Tsuchinshan-ATLAS should be visible between them. By Oct. 14, the comet may remain visible at the midway point between the bright star Arcturus and the planet Venus.

“And savor the view,” Cooke advised – because by early November, the comet will be gone again for the next 800 centuries.

It’s highly unlikely Tsuchinshan-ATLAS will be visible in daylight hours, except perhaps at twilight, Cooke said. In the past 300 years of astronomical observation, only nine previous comets have been bright enough to spot during the day. The last were Comet West in 1976 and, under ideal conditions, Comet Hale-Bopp in 1997.

The brightness of comets is measured on the same scale we use for stars, one that has been in use since roughly 150 B.C., when it was devised by the ancient scholar Hipparchus and refined by the astronomer Ptolemy. Stellar magnitude is measured on a logarithmic scale, which makes a magnitude 1 star exactly 100 times brighter than a magnitude 6 star. The lower the number the brighter the object, making it more likely to be clearly seen, whether by telescope or the naked eye.

Comets traveling through the inner solar system aren’t uncommon, but many never survive a close pass by the Sun. Icy comet ISON, photographed here on Nov. 19, 2013, reached solar perihelion later that month – but couldn’t endure the punishing heat and gravity so close to Earth’s parent star and disintegrated.
Comets traveling through the inner solar system aren’t uncommon, but many never survive a close pass by the Sun. Icy comet ISON, photographed here on Nov. 19, 2013, reached solar perihelion later that month – but couldn’t endure the punishing heat and gravity so close to Earth’s parent star and disintegrated.
NASA/Aaron Kingery

“Typically, a comet would have to reach a magnitude of –6 to –10 to be seen in daylight,” Cooke said. “That’s extremely rare.”

At peak visibility in the northern hemisphere, Tsuchinshan-ATLAS’s brightness is estimated at between 2 and 4. In comparison, the brightest visible star in the night sky, Sirius, has a magnitude of –1.46. At its brightest, solar reflection from Venus is a magnitude of –4. The International Space Station sometimes achieves a relative brightness of –6.

Comets are often hard to predict because they’re extended objects, Cooke noted, with their brightness spread out and often dimmer than their magnitude suggests. At the same time, they may benefit from a phenomenon called “forward scattering,” which causes sunlight to bounce more intensely off all the gas and debris in the comet’s tail and its coma – the glowing nebula that develops around it during close stellar orbit – and causing a more intense brightening effect for observers.

“If there is a lot of forward scattering, the comet could be as bright as magnitude –1,” Cooke said. That could make it “visible to the unaided eye or truly spectacular with binoculars or a small telescope.”

What will become of Comet Tsuchinshan-ATLAS? Cooke noted that it is not expected to draw too near the planetary giants of our system, but eventually could be flung out of the solar system – like a stone from a sling – due to the gravitational influence of other worlds and its own tenuous bond with the Sun.

But the hardy traveler likely still has miles to go yet. “I learned a long time ago not to gamble on comets,” Cooke said. “We’ll have to wait and see.”

Smith, an Aeyon employee, supports the Marshall Office of Communications.

› Back to Top

Via NASA Plane, Scientists Find New Gamma-ray Emission in Storm Clouds

There’s more to thunderclouds than rain and lightning. Along with visible light emissions, thunderclouds can produce intense bursts of gamma rays, the most energetic form of light, that last for millionths of a second. The clouds can also glow steadily with gamma rays for seconds to minutes at a time.

NASA’s high-flying ER-2 airplane carries instrumentation in this artist’s impression of the ALOFT mission to record gamma rays (colored purple for illustration) from thunderclouds.
NASA’s high-flying ER-2 airplane carries instrumentation in this artist’s impression of the ALOFT mission to record gamma rays (colored purple for illustration) from thunderclouds.
Oscar van der Velde

Researchers using NASA airborne platforms have now found a new kind of gamma-ray emission that’s shorter in duration than the steady glows and longer than the microsecond bursts. They’re calling it a flickering gamma-ray flash. The discovery fills in a missing link in scientists’ understanding of thundercloud radiation and provides new insights into the mechanisms that produce lightning. The insights, in turn, could lead to more accurate lightning risk estimates for people, aircraft, and spacecraft.

Researchers from the University of Bergen in Norway led the study in collaboration with scientists from NASA’s Marshall Space Flight Center and Goddard Space Flight Center, the U.S. Naval Research Laboratory, and multiple universities in the U.S., Mexico, Colombia, and Europe. The findings were described in a pair of papers in Nature, published Oct. 2.

The international research team made their discovery while flying a battery of detectors aboard a NASA ER-2 research aircraft. In July 2023, the ER-2 set out on a series of 10 flights from MacDill Air Force Base in Tampa, Florida. The plane flew figure-eight flight patterns a few miles above tropical thunderclouds in the Caribbean and Central America, providing unprecedented views of cloud activity.

The scientific payload was developed for the Airborne Lightning Observatory for Fly’s Eye Geostationary Lightning Mapper Simulator and Terrestrial Gamma-ray Flashes (ALOFT) campaign. Instrumentation in the payload included weather radars along with multiple sensors for measuring gamma rays, lightning flashes, and microwave emissions from clouds. 

The researchers had hoped ALOFT instruments would observe fast radiation bursts known as terrestrial gamma-ray flashes (TGFs). The flashes, first discovered in 1992 by NASA’s Compton Gamma Ray Observatory spacecraft, accompany some lightning strikes and last only millionths of a second. Despite their high intensity and their association with visible lightning, few TGFs have been spotted during previous aircraft-based studies.  

“I went to a meeting just before the ALOFT campaign,” said principal investigator Nikolai Østgaard, a space physicist with the University of Bergen. “And they asked me: ‘How many TGFs are you going to see?’ I said: ‘Either we’ll see zero, or we’ll see a lot.’ And then we happened to see 130.” 

However, the flickering gamma-ray flashes were a complete surprise.

NASA’s high-flying ER-2 airplane carries instrumentation in this artist’s impression of the ALOFT mission to record gamma rays (colored purple for illustration) from thunderclouds.
NASA’s high-flying ER-2 airplane carries instrumentation in this artist’s impression of the ALOFT mission to record gamma rays (colored purple for illustration) from thunderclouds.
NASA/ALOFT team

“They’re almost impossible to detect from space,” said co-principal investigator Martino Marisaldi, who is also a University of Bergen space physicist. “But when you are flying at 20 kilometers (12.5 miles) high, you’re so close that you will see them.” The research team found more than 25 of these new flashes, each lasting between 50 to 200 milliseconds. 

The abundance of fast bursts and the discovery of intermediate-duration flashes could be among the most important thundercloud discoveries in a decade or more, said University of New Hampshire physicist Joseph Dwyer, who was not involved in the research. “They’re telling us something about how thunderstorms work, which is really important because thunderstorms produce lightning that hurts and kills a lot of people.” 

More broadly, Dwyer said he is excited about the prospects of advancing the field of meteorology. “I think everyone assumes that we figured out lightning a long time ago, but it’s an overlooked area … we don’t understand what’s going on inside those clouds right over our heads.” The discovery of flickering gamma-ray flashes may provide crucial clues scientists need to understand thundercloud dynamics, he said.

Turning to aircraft-based instrumentation rather than satellites ensured a lot of bang for research bucks, said the study’s project scientist, Timothy Lang of Marshall. 

“If we had gotten one flash, we would have been ecstatic – and we got well over 100,” he said. This research could lead to a significant advance in our understanding of thunderstorms and radiation from thunderstorms. “It shows that if you have the right problem and you’re willing to take a little bit of risk, you can have a huge payoff.”

› Back to Top

NASA SPoRT’s Sea Surface Temperature Data Driving Forecast Accuracy, Timely Weather Support

By Paola Pinto

NASA Short-term Prediction Research and Transition (SPoRT) Center’s sea surface temperature (SST) product is a pivotal resource for enhancing weather analysis, forecasting, and marine safety at the National Weather Service (NWS) and within the coastal/marine user community.

NASA SPoRT's viewer displaying the Sea Surface Temperature (SST) product for the continental U.S.
NASA SPoRT’s viewer displaying the Sea Surface Temperature (SST) product for the continental U.S.
NASA

Its real-world applications range from improving weather forecasts to enhancing marine safety. What sets this SST product apart from others is its integration of data from multiple satellites, generating a high-resolution 7-day composite at a 2 km resolution. By combining observations from five satellites – three VIIRS and two AVHRR on polar-orbiting satellites like SNPP and MetOp – it achieves around 80% coverage of SST data that are less than two days old, ensuring timely and accurate insights for remote ocean areas, coastal regions, and large lakes. This advanced system supports critical functions such as tropical storm monitoring, visibility forecasts, and ice formation predictions.

David Marsalek, a meteorologist with NOAA’s NWS in Cleveland, Ohio, highlights the value of SST data for the safety of the Great Lakes, particularly for shipping and recreational activities. Marsalek, who has been focused on marine conditions, notes the dual role of SST data in both summer and winter.

“For us at WFO Cleveland, SST data is vital year-round,” Marsalek said. During winter, Marsalek emphasizes the role of SST data in forecasting ice formation. He indicates that in Lake Erie, during colder months, the SST product from NASA SPoRT is crucial for predicting ice formation for Great Lakes interests.

“Our office relies heavily on this data to issue ice outlooks for the pre-ice season in fall and early winter and advisories for situations such as rapid ice growth,” he said. “Without it, we would struggle to provide accurate long-term forecasts, especially as buoys are often removed before ice forms.”

The SPoRT SST product helps his team bridge this gap, enabling them to make informed predictions about ice development.

Brian LaMarre, a meteorologist with NWS in Tampa Bay, Florida, said SPoRT SST data, introduced through a pilot project from 2012 to 2015, has become essential for Tampa Bay’s 24/7 forecasting and warnings. The high-resolution SST data is crucial for maritime navigation, particularly in improving marine channel forecasts and helping forecasters anticipate visibility restrictions due to fog in the Port of Tampa Bay. By integrating the SPoRT SST product with air and dewpoint temperature forecasts, forecasters can diagnose when fog will form due to warm, moist air flowing over cooler SSTs in the channel, especially during the Florida fog season from late fall into early spring. This accurate forecasting is essential for Tampa Bay’s largest port, which handles $18 billion in trade annually. Unanticipated port closures due to fog can have a significant economic impact, halting shipping operations and causing costly delays.

“This data supports decision making for the Coast Guard and harbor pilots,” LaMarre said.

From August, NOAA/NWS/NHC's predicted track and intensity forecasts and cone of uncertainty for Tropical Storm Ernesto overlaid on top of the latest NASA SPoRT SST Composite in the nowCOAST.
From August, NOAA/NWS/NHC’s predicted track and intensity forecasts and cone of uncertainty for Tropical Storm Ernesto overlaid on top of the latest NASA SPoRT SST Composite in the nowCOAST.
NASA/NWS/nowCOAST

Additionally, SPoRT SST data aids in assessing water temperature impacts during major weather events like hurricanes, further ensuring the safety and economic viability of the region. LaMarre also highlighted how SST data provides timely temperature forecasts to local organizations focused on marine life rescue. This helps them quickly deploy rescue missions for wildlife, such as sea turtles and manatees, affected by cold water stunning events.

John Kelley and his nowCOAST Team at NOAA’s National Ocean Service Coastal Marine Modeling Branch within the Coast Survey Development Lab have made NASA SPoRT SST composites available via nowCOAST’s web mapping services and GIS-based map viewer for the past nine years. On average, nowCoast receives around 400,000 monthly hits and even higher web traffic during severe weather events; some users include state agencies, the Coast Guard, and marine industry professionals.

“The SPoRT SST composite is integrated with a variety of data and information from NOAA, such as tropical cyclone track and intensity forecasts, lightning strike density maps, and marine weather warnings, to support critical operations like marine navigation, coastal resiliency, and disaster preparedness and response,” Kelley said. Accurate SST data plays a key role in helping vessels navigate safely through shifting ocean temperatures and currents, which can affect fuel efficiency, weather conditions, and route planning. It also supports coastal communities by providing timely data to anticipate severe weather events, such as hurricanes, which can impact ecosystems and infrastructure.

Kelley said SPoRT SST is also used to evaluate the accuracy of short-range predictions from the National Ocean Service operational numerical oceanographic forecast models for both coastal oceans and the Great Lakes. Recently, the composites have been crucial in evaluating lake surface temperature predictions for large, non-Great Lakes inland lakes, where in-situ water temperature observations are often unavailable.

“The SPoRT SST composites provide critical verification data for large lakes where in-situ water temperature observations are not available,” Kelley said.

The SPoRT center was established in 2002 at NASA’s Marshall Space Flight Center to transition NASA satellite products and capabilities to the operational weather community to improve short-term weather forecasting.

Pinto is a research associate at the University of Alabama in Huntsville, specializing in communications and user engagement for NASA SPoRT.

› Back to Top

View the full article

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Similar Topics

    • By NASA
      1 min read
      Preparations for Next Moonwalk Simulations Underway (and Underwater)
      Dr. Misty Davies receives the prestigious AIAA Fellowship in May 2024 for her contributions to aerospace safety and autonomous systems, recognized at a ceremony in Washington, DC.NASA In May 2024, Dr. Misty Davies joined the American Institute of Aeronautics and Astronautics (AIAA) Class of 2024 Fellows at a ceremony in Washington, DC.  The AIAA website states that, “AIAA confers Fellow upon individuals in recognition of their notable and valuable contributions to the arts, sciences or technology of aeronautics and astronautics.”  The first AIAA Fellows were elected in 1934; since then only 2064 people have been selected for the honor.  Dr. Davies has focused her career at NASA Ames Research Center on developing tools and techniques that enable the safety assurance of increasingly autonomous systems.  She currently serves as the Associate Chief for Aeronautics Systems in the Intelligent Systems Division at NASA Ames and is the Aerospace Operations and Safety Program (AOSP) Technical Advisor for Assurance and Safety. More information on AIAA Fellows is at https://www.aiaa.org/news/news/2024/02/08/aiaa-announces-class-of-2024-honorary-fellows-and-fellows
      Share
      Details
      Last Updated Nov 22, 2024 Related Terms
      General Explore More
      8 min read SARP East 2024 Ocean Remote Sensing Group
      Article 52 mins ago 10 min read SARP East 2024 Atmospheric Science Group
      Article 52 mins ago 10 min read SARP East 2024 Hydroecology Group
      Article 52 mins ago Keep Exploring Discover Related Topics
      Missions
      Humans in Space
      Climate Change
      Solar System
      View the full article
    • By NASA
      8 min read
      Preparations for Next Moonwalk Simulations Underway (and Underwater)
      Return to 2024 SARP Closeout Faculty Advisors:
      Dr. Tom Bell, Woods Hole Oceanographic Institution
      Dr. Kelsey Bisson, NASA Headquarters Science Mission Directorate
      Graduate Mentor:
      Kelby Kramer, Massachusetts Institute of Technology

      Kelby Kramer, Graduate Mentor
      Kelby Kramer, graduate mentor for the 2024 SARP Ocean Remote Sensing group, provides an introduction for each of the group members and shares behind-the scenes moments from the internship.
      Lucas DiSilvestro
      Shallow Water Benthic Cover Type Classification using Hyperspectral Imagery in Kaneohe Bay, Oahu, Hawaii
      Lucas DiSilvestro
      Quantifying the changing structure and extent of benthic coral communities is essential for informing restoration efforts and identifying stressed regions of coral. Accurate classification of shallow-water benthic coral communities requires high spectral and spatial resolution, currently not available on spaceborne sensors, to observe the seafloor through an optically complex seawater column. Here we create a shallow water benthic cover type map of Kaneohe Bay, Oahu, Hawaii using the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) without requiring in-situ data as inputs. We first run the AVIRIS data through a semi-analytical inversion model to derive color dissolved organic matter, chlorophyll concentration, bottom albedo, suspended sediment, and depth parameters for each pixel, which are then matched to a Hydrolight simulated water column. Pure reflectance for coral, algae, and sand are then projected through each water column to create spectral endmembers for each pixel. Multiple Endmember Spectral Mixture Analysis (MESMA) provides fractional cover of each benthic class on a per-pixel basis. We demonstrate the efficacy of using simulated water columns to create surface reflectance spectral endmembers as Hydrolight-derived in-situ endmember spectra strongly match AVIRIS surface reflectance for corresponding locations (average R = 0.96). This study highlights the capabilities of using medium-fine resolution hyperspectral imagery to identify fractional cover type of localized coral communities and lays the groundwork for future spaceborne hyperspectral monitoring of global coral communities.

      Atticus Cummings
      Quantifying Uncertainty In Kelp Canopy Remote Sensing Using the Harmonized Landsat Sentinel-2 Dataset
      Atticus Cummings
      California’s giant kelp forests serve as a major foundation for the region’s rich marine biodiversity and provide recreational and economic value to the State of California. With the rising frequency of marine heatwaves and extreme weather onset by climate change, it has become increasingly important to study these vital ecosystems. Kelp forests are highly dynamic, changing across several timescales; seasonally due to nutrient concentrations, waves, and predator populations, weekly with typical growth and decay, and hourly with the tides and currents. Previous remote sensing of kelp canopies has relied on Landsat imagery taken with a eight-day interval, limiting the ability to quantify more rapid changes. This project aims to address uncertainty in kelp canopy detection using the Harmonized Landsat and Sentinel-2 (HLS) dataset’s zero to five-day revisit period. A random forest classifier was used to identify pixels that contain kelp, on which Multiple Endmember Spectral Mixture Analysis (MESMA) was then run to quantify intrapixel kelp density. Processed multispectral satellite images taken within 3 days of one another were paired for comparison. The relationship between fluctuations in kelp canopy density with tides and currents was assessed using in situ data from an acoustic doppler current profiler (ADCP) at the Santa Barbara Long Term Ecological Research site (LTER) and a NOAA tidal buoy. Preliminary results show that current and tidal trends cannot be accurately correlated with canopy detection due to other sources of error. We found that under cloud-free conditions, canopy detection between paired images varied on average by 42%. Standardized image processing suggests that this uncertainty is not created within the image processing step, but likely arises due to exterior factors such as sensor signal noise, atmospheric conditions, and sea state. Ultimately, these errors could lead to misinterpretation of remotely sensed kelp ecosystems, highlighting the need for further research to identify and account for uncertainties in remote sensing of kelp canopies.

      Jasmine Sirvent
      Kelp Us!: A Methods Analysis for Predicting Kelp Pigment Concentrations from Hyperspectral Reflectance
      Jasmine Sirvent
      Ocean color remote sensing enables researchers to assess the quantity and physiology of life in the ocean, which is imperative to understanding ecosystem health and formulating accurate predictions. However, without proper methods to analyze hyperspectral data, correlations between spectral reflectance and physiological traits cannot be accurately derived. In this study, I explored different methods—single variable regression, partial least squares regressions (PLSR), and derivatives—in analyzing in situ Macrocystis pyrifera (giant kelp) off the coast of Santa Barbara, California in order to predict pigment concentrations from AVIRIS hyperspectral reflectance. With derivatives as a spectral diagnostic tool, there is evidence suggesting high versus low pigment concentrations could be diagnosed; however, the fluctuations were within 10 nm of resolution, thus AVIRIS would be unable to reliably detect them. Exploring a different method, I plotted in situ pigment measurements — chlorophyll a, fucoxanthin, and the ratio of fucoxanthin to chlorophyll a—against hyperspectral reflectance that was resampled to AVIRIS bands. PLSR proved to be a more successful model because of its hyperdimensional analysis capabilities in accounting for multiple wavelength bands, reaching R2 values of 0.67. Using this information, I constructed a model that predicts kelp pigments from simulated AVIRIS reflectance using a spatial time series of laboratory spectral measurements and photosynthetic pigment concentrations. These results have implications, not only for kelp, but many other photosynthetic organisms detectable by hyperspectral airborne or satellite sensors. With these findings, airborne optical data could possibly predict a plethora of other biogeochemical traits. Potentially, this research would permit scientists to acquire data analogous to in situ measurements about floating matters that cannot financially and pragmatically be accessed by anything other than a remote sensor.

      Isabelle Cobb
      Correlations Between SSHa and Chl-a Concentrations in the Northern South China Sea
      Isabelle Cobb
      Sea surface height anomalies (SSHa)–variations in sea surface height from climatological averages–occur on seasonal timescales due to coastal upwelling and El Niño-Southern Oscillation (ENSO) cycles. These anomalies are heightened when upwelling plumes bring cold, nutrient-rich water to the surface, and are particularly strong along continental shelves in the Northern South China Sea (NSCS). This linkage between SSHa and nutrient availability has interesting implications for changing chlorophyll-a (chl-a) concentrations, a prominent indicator of phytoplankton biomass that is essential to the health of marine ecosystems. Here, we evaluate the long-term (15 years) relationship between SSHa and chl-a, in both satellite remote sensing data and in situ measurements. Level 3 SSHa data from Jason 1/2/3 satellites and chl-a data from MODIS Aqua were acquired and binned to monthly resolution. We found a significant inverse correlation between SSHa and chl-a during upwelling months in both the remote sensing (Spearman’s R=-0.57) and in situ data, with higher resolution in situ data from ORAS4 (an assimilation of buoy observations from 2003-2017) showing stronger correlations (Spearman’s R=-0.75). In addition, the data reveal that the magnitude of SSH increases with time during instances of high correlation, possibly indicating a trend of increased SSH associated with reduced seasonal chl-a concentrations. Thus, this relationship may inform future work predicting nutrient availability and threats to marine ecosystems as climate change continues to affect coastal sea surface heights.

      Alyssa Tou
      Exploring Coastal Sea Surface Temperature Anomalies and their effect on Coastal Fog through analyzing Plant Phenology
      Alyssa Tou
      Marine heat waves (MHW) have been increasing in frequency, duration and intensity, giving them substantial potential to influence ecosystems. Do these MHWs sufficiently enhance coastal precipitation such that plant growth is impacted? Recently, the Northeast Pacific experienced a long, intense MHW in 2014/2015, and another short, less intense MHW in 2019/2020. Here we investigate how the intensity and duration of MHWs influence the intensity and seasonal cycle of three different land cover types (‘grass’, ‘trees’, and a combination of both ‘combined’’) to analyze plant phenology trends in Big Sur, California. We hypothesize that longer intense MHWs decrease the ocean’s evaporative capacity, decreasing fog, thus lowering plant productivity, as measured by Normalized Difference Vegetation Index (NDVI). Sea surface temperature (SST) and NDVI data were collected from the NOAA Coral Reef Watch, and NASA MODIS/Terra Vegetation Indices 16-Day L3 Global 250m products respectively. Preliminary results show no correlation (R2=0.02) between SSTa and combined NDVI values and no correlation (R2=0.01) between SST and NDVI. This suggests that years with anomalously high SST do not significantly impact plant phenology. During the intense and long 2014/2015 MHW, peak NDVI values for ‘grass’ and ‘combined’ pixels were 2.0 and 1.7 standard deviations above the climatological average, while the shorter 2019/2020 MHW saw higher peaks of 3.2 and 2.4 standard deviations. However, the ‘grass’, ‘tree’ and ‘combined’ NDVI anomalies were statistically insignificant during both MHWs, showing that although NDVI appeared to increase during the shorter and less intense MHW, these values may be attributed to other factors. The data qualitatively suggest that MHW’s don’t impact the peak NDVI date, but more data at higher temporal resolution are necessary. Further research will involve analyzing fog indices and exploring confounding variables impacting NDVI, such as plant physiology, anthropogenic disturbance, and wildfires. In addition, it’s important to understand to what extent changes in NDVI are attributed to the driving factors of MHWs or the MHWs themselves. Ultimately, mechanistically understanding the impacts MHW intensity and duration have on terrestrial ecosystems will better inform coastal community resilience.


      Return to 2024 SARP Closeout Share
      Details
      Last Updated Nov 22, 2024 Related Terms
      General Explore More
      10 min read SARP East 2024 Atmospheric Science Group
      Article 21 mins ago 10 min read SARP East 2024 Hydroecology Group
      Article 21 mins ago 11 min read SARP East 2024 Terrestrial Fluxes Group
      Article 22 mins ago View the full article
    • By NASA
      10 min read
      Preparations for Next Moonwalk Simulations Underway (and Underwater)
      Return to 2024 SARP Closeout Faculty Advisors:
      Dr. Guanyu Huang, Stony Brook University
      Graduate Mentor:
      Ryan Schmedding, McGill University

      Ryan Schmedding, Graduate Mentor
      Ryan Schmedding, graduate mentor for the 2024 SARP Atmospheric Science group, provides an introduction for each of the group members and shares behind-the scenes moments from the internship.
      Danielle Jones
      Remote sensing of poor air quality in mountains: A case study in Kathmandu, Nepal
      Danielle Jones
      Urban activity produces particulate matter in the atmosphere known as aerosol particles. These aerosols can negatively affect human health and cause changes to the climate system. Measures for aerosols include surface level PM2.5 concentration and aerosol optical depth (AOD). Kathmandu, Nepal is an urban area that rests in a valley on the edge of the Himalayas and is home to over three million people. Despite the prevailing easterly winds, local aerosols are mostly concentrated in the valley from the residential burning of coal followed by industry. Exposure to PM2.5 has caused an estimated ≥8.6% of deaths annually in Nepal. We paired NASA satellite AOD and elevation data, model  meteorological data, and local AirNow PM2.5 and air quality index (AQI) data to determine causes of variation in pollutant measurement during 2023, with increased emphasis on the post-monsoon season (Oct. 1 – Dec. 31). We see the seasonality of meteorological data related to PM2.5 and AQI. During periods of low temperature, low wind speed, and high pressure, PM2.5 and AQI data slightly diverge. This may indicate that temperature inversions increase surface level concentrations of aerosols but have little effect on the total air column. The individual measurements of surface pressure, surface temperature, and wind speed had no observable correlation to AOD (which was less variable than PM2.5 and AQI over the entire year). Elevation was found to have no observable effect on AOD during the period of study. Future research should focus on the relative contributions of different pollutants to the AQI to test if little atmospheric mixing causes the formation of low-altitude secondary pollutants in addition to PM2.5 leading to the observed divergence in AQI and PM2.5.

      Madison Holland
      Analyzing the Transport and Impact of June 2023 Canadian Wildfire Smoke on Surface PM2.5 Levels in Allentown, Pennsylvania
      Madison Holland
      The 2023 wildfire season in Canada was unparalleled in its severity. Over 17 million hectares burned, the largest area ever burned in a single season. The smoke from these wildfires spread thousands of kilometers, causing a large population to be exposed to air pollution. Wildfires can release a variety of air pollutants, including fine particulate matter (PM2.5). PM2.5 directly affects human health – exposure to wildfire-related PM2.5 has been associated with respiratory issues such as the exacerbation of asthma and chronic obstructive pulmonary disease. In June 2023, smoke from the Canadian wildfires drifted southward into the United States. The northeastern United States reported unhealthy levels of air quality due to the transportation of the smoke. In particular, Pennsylvania reported that Canadian wildfires caused portions of the state to have “Hazardous” air quality. Our research focused on how Allentown, PA experienced hazardous levels of air quality from this event. To analyze the concentrations of PM2.5 at the surface level, NASA’s Hazardous Air Quality Ensemble System (HAQES) and the EPA’s Air Quality System (AQS) ground-based site data were utilized. By comparing HAQES’s forecast of hazardous air quality events with recorded daily average PM2.5 with the EPA’s AQS, we were able to compare how well the ensemble system was at predicting total PM2.5 during unhealthy air quality days. NOAA’s Hybrid Single-Particle Lagrangian Integrated Trajectory model, pyrsig, and the Canadian National Fire Database were used. These datasets revealed the trajectory of aerosols from the wildfires to Allentown, Pennsylvania, identified the densest regions of the smoke plumes, and provided a map of wildfire locations in southeastern Canada. By integrating these datasets, we traced how wildfire smoke transported aerosols from the source at the ground level.

      Michele Iraci
      Trends and Transport of Tropospheric Ozone From New York City to Connecticut in the Summer of 2023
      Michele Iraci
      Tropospheric Ozone, or O₃, is a criteria pollutant contributing to most of Connecticut and New York City’s poor air quality days. It has adverse effects on human health, particularly for high-risk individuals. Ozone is produced by nitrogen oxides and volatile organic compounds from fuel combustion reacting with sunlight. The Ozone Transport Region (OTR) is a collection of states in the Northeast and Mid-Atlantic United States that experience cross-state pollution of O₃. Connecticut has multiple days a year where O₃ values exceed the National Ambient Air Quality Standards requiring the implementation of additional monitoring and standards because it falls in the OTR. Partially due to upstream transport from New York City, Connecticut experiences increases in O₃ concentrations in the summer months. Connecticut has seen declines in poor air quality days from O₃ every year due to the regulations on ozone and its precursors. We use ground-based Lidar, Air Quality System data, and a back-trajectory model to examine a case of ozone enhancement in Connecticut caused by air pollutants from New York between June and August 2023. In this time period, Connecticut’s ozone enhancement was caused by air pollutants from New York City. As a result, New York City and Connecticut saw similar O₃ spikes and decline trends. High-temperature days increase O₃ in both places, and wind out of the southwest may transport O₃ to Connecticut. Production and transport of O₃ from New York City help contribute to Connecticut’s poor air quality days, resulting in the need for interstate agreements on pollution management.

      Stefan Sundin
      Correlations Between the Planetary Boundary Layer Height and the Lifting Condensation Level
      Stefan Sundin
      The Planetary Boundary Layer (PBL) characterizes the lowest layer in the atmosphere that is coupled with diurnal heating at the surface. The PBL grows during the day as solar heating causes pockets of air near the surface to rise and mix with cooler air above. Depending on the type of terrain and surface albedo that receives solar heating, the depth of the PBL can vary to a great extent. This makes PBL height (PBLH) a difficult variable to quantify spatially and temporally. While several methods have been used to obtain the PBLH such as wind profilers and lidar techniques, there is still a level of uncertainty associated with PBLH. One method of predicting seasonal PBLH fluctuation and potentially lessening uncertainty that will be discussed in this study is recognizing a correlation in PBLH with the lifting condensation level (LCL). Like the PBL, the LCL is used as a convective parameter when analyzing upper air data, and classifies the height in the atmosphere at which a parcel becomes saturated when lifted by a forcing mechanism, such as a frontal boundary, localized convergence, or orographic lifting. A reason to believe that PBLH and LCL are interconnected is their dependency on both the amount of surface heating and moisture that is present in the environment. These thermodynamic properties are of interest in heavily populated metropolitan areas within the Great Plains, as they are more susceptible to severe weather outbreaks and associated economic losses. Correlations between PBLH and LCL over the Minneapolis-St. Paul metropolitan statistical area during the summer months of 2019-2023 will be discussed.

      Angelica Kusen
      Coupling of Chlorophyll-a Concentrations and Aerosol Optical Depth in the Subantarctic Southern Ocean and South China Sea (2019-2021)
      Angelica Kusen
      Air-sea interactions form a complex feedback mechanism, whereby aerosols impact physical and biogeochemical processes in marine environments, which, in turn, alter aerosol properties. One key indicator of these interactions is chlorophyll-a (Chl-a), a pigment common to all phytoplankton and a widely used proxy for primary productivity in marine ecosystems. Phytoplankton require soluble nutrients and trace metals for growth, which typically come from oceanic processes such as upwelling. These nutrients can also be supplied via wet and dry deposition, where atmospheric aerosols are removed from the atmosphere and deposited into the ocean. To explore this interaction, we analyze the spatial and temporal variations of satellite-derived chl-a and AOD, their correlations, and their relationship with wind patterns in the Subantarctic Southern Ocean and the South China Sea from 2019 to 2021, two regions with contrasting environmental conditions.
      In the Subantarctic Southern Ocean, a positive correlation (r²= 0.26) between AOD and Chl-a was found, likely due to dust storms following Austrian wildfires. Winds deposit dust aerosols rich in nutrients, such as iron, to the iron-limited ocean, enhancing phytoplankton photosynthesis and increasing chl-a. In contrast, the South China Sea showed no notable correlation (r² = -0.02) between AOD and chl-a. Decreased emissions due to COVID-19 and stricter pollution controls likely reduced the total AOD load and shifted the composition of aerosols from anthropogenic to more natural sources.
      These findings highlight the complex interrelationship between oceanic biological activity and the chemical composition of the atmosphere, emphasizing that atmospheric delivery of essential nutrients, such as iron and phosphorus, promotes phytoplankton growth. Finally, NASA’s recently launched PACE mission will contribute observations of phytoplankton community composition at unprecedented scale, possibly enabling attribution of AOD levels to particular groups of phytoplankton.

      Chris Hautman
      Estimating CO₂ Emission from Rocket Plumes Using in Situ Data from Low Earth Atmosphere
      Chris Hautman
      Rocket emissions in the lower atmosphere are becoming an increasing environmental concern as space exploration and commercial satellite launches have increased exponentially in recent years. Rocket plumes are one of the few known sources of anthropogenic emissions directly into the upper atmosphere. Emissions in the lower atmosphere may also be of interest due to their impacts on human health and the environment, in particular, ground level pollutants transported over wildlife protected zones, such as the Everglades, or population centers near launch sites. While rockets are a known source of atmospheric pollution, the study of rocket exhaust is an ongoing task. Rocket exhaust can have a variety of compositions depending on the type of engine, the propellants used, including fuels, oxidizers, and monopropellants, the stoichiometry of the combustion itself also plays a role. In addition, there has been increasing research into compounds being vaporized in atmospheric reentry. These emissions, while relatively minimal compared to other methods of travel, pose an increasing threat to atmospheric stability and environmental health with the increase in human space activity. This study attempts to create a method for estimating the total amount of carbon dioxide released by the first stage of a rocket launch relative to the mass flow of RP-1, a highly refined kerosene (C₁₂H₂₆)), and liquid oxygen (LOX) propellants. Particularly, this study will focus on relating in situ CO₂ emission data from a Delta II rocket launch from Vandenberg Air Force Base on April 15, 1999, to CO₂ emissions from popular modern rockets, such as the Falcon 9 (SpaceX) and Soyuz variants (Russia). The findings indicate that the CO₂ density of any RP-1/LOX rocket is 6.9E-7 times the mass flow of the sum of all engines on the first stage. The total mass of CO₂ emitted can be further estimated by modeling the volume of the plume as cylindrical. Therefore, the total mass can be calculated as a function of mass flow and first stage main engine cutoff. Future CO₂ emissions on an annual basis are calculated based on these estimations and anticipated increases in launch frequency.


      Return to 2024 SARP Closeout Share
      Details
      Last Updated Nov 22, 2024 Related Terms
      General Explore More
      8 min read SARP East 2024 Ocean Remote Sensing Group
      Article 21 mins ago 10 min read SARP East 2024 Hydroecology Group
      Article 21 mins ago 11 min read SARP East 2024 Terrestrial Fluxes Group
      Article 22 mins ago View the full article
    • By NASA
      10 min read
      Preparations for Next Moonwalk Simulations Underway (and Underwater)
      Return to 2024 SARP Closeout Faculty Advisors:
      Dr. Dom Ciruzzi, College of William & Mary
      Graduate Mentor:
      Marley Majetic, Pennsylvania State University

      Marley Majetic, Graduate Mentor
      Marley Majetic, graduate mentor for the 2024 SARP Hydroecology group, provides an introduction for each of the group members and shares behind-the scenes moments from the internship.
      Jordan DiPrima
      How are different land cover types affected by land subsidence on the U.S. Atlantic Coast?
      Jordan DiPrima
      Land subsidence is a frequently overlooked geologic hazard that is caused by natural processes and, more recently, anthropogenic stressors. The goal of this study is to observe subsidence trends and hotspots among land cover types on Virginia’s Eastern Shore and Long Island, New York. This study utilizes interferometric synthetic aperture radar, or InSAR, satellite data from Sentinel-1 to map vertical land motion from 2017 to 2023. Land cover data were sourced from Landsat 8 satellite imagery. Subsidence was mapped within the following land cover types on the Eastern Shore: urban, wetland, cropland, temperate or sub-polar grassland, temperate or sub-polar shrubland, mixed forest, and temperate or subpolar needleleaf forest. These land cover types have mean vertical velocities ranging from -0.2 mm/yr to -5.2 mm/yr. Results suggest that land subsidence is most severe in cropland areas on the Eastern Shore, with a mean vertical velocity of -5.2 mm/yr. In contrast, wetlands display the most subsidence on Long Island with a mean vertical velocity of -2.1 mm/yr. Long Island lacked distinct trends among land cover types and instead showed evidence of subsidence hotspots. These hotspots exist in the following land cover types: temperate or sub-polar grassland, barren lands, wetland, cropland, and temperate or sub-polar broadleaf deciduous forest. Overall, Eastern Shore croplands and Long Island wetlands were determined to be the most susceptible land cover types. These findings highlight regions at risk of sea level rise, flooding, and coastal erosion as a result of subsidence. With further research, we can map subsiding landscapes on a global scale to improve resource allocation and mitigation techniques.

      Isabelle Peterson
      Total Thermokarst Lake Changes on the Seward Peninsula, Alaska: 2016 to 2024
      Isabelle Peterson
      Thermokarst landscapes have and will continue to change as the arctic landscape warms due to climate change. Permafrost underlies much of these arctic landscapes, and as it melts, thermokarst landscapes are left behind. The Seward Peninsula in Alaska has an abundance of these landscapes, and thermokarst lakes are present in the northernmost portion. Several lakes have come and gone, but with increasing climate instability and warming of the area, there is a possibility of more permafrost melting, creating more of these lakes. To capture these changes, Harmonized Landsat Sentinel-2 (HLS) imagery were used to create annual lake maps of the northern portion of the Seward Peninsula from 2016 to 2024. Much of the methodology was informed from Jones et al. (2011); however, their study used eCognition, while the present study used ArcGIS Pro. This caused some differences in results likely due to the differences in software, satellite imagery, and the proposed study area. Lake number changes were observed annually. From this annual change, several 10 to 40 ha lakes disappeared and reappeared within the study period, along with smaller lakes filling in where larger lakes once were. Thermokarst lake drainage is a process described by Jones and Arp (2015) which has devastating geomorphological impacts on the surrounding area, creating large drainage troughs which diminish surrounding permafrost in a quick time frame. To capture these events and overall changes, satellite imagery is essential. This is especially true in remote regions which are hard to reach by foot and require flight missions to be scheduled over the area for aerial photography. However, LVIS and other higher resolution aerial instruments would provide higher accuracy when identifying smaller lakes, as satellite imagery does not accurately capture lakes below 1 ha in the study area. This assertion is made due to conflicting results compared to Jones et al (2011). While the methodologies of this study have been executed manually, Qin, Zhang, and Lu (2023) have proposed the idea of using Sentinel-2 imagery to map thermokarst lakes through automatic methods. While automatization has not yet been perfected, the potential is there and can be used to analyze thermokarst areas effectively. With more satellite imagery, annual, monthly, and potentially daily changes can be captured in favorable months to monitor changing landscapes in arctic regions. Thermokarst lakes have been changing, and monitoring them can help in the process of understanding the changing climate in arctic areas, especially through the lens melting permafrost.

      Emmanelle Cuasay
      Finding Refuge in Climate Crisis: Analyzing the Differences between Refugia and Non-Refugia in the Northern Philippines Using Remote Sensing
      Emmanelle Cuasay
      Refugia are areas that are characterized by stable environmental conditions that can act as a refuge for species as Earth’s climate warms. In this study, fourteen Harmonized Landsat Sentinel-2 images from February 2014 – March 2024 of the northern Philippines region were used. The region of interest is the terrestrial biome by Lake Taal. Normalized Difference Vegetation Index (NDVI) maps were created from all fourteen images to determine the NDVI 25th highest quartiles of the long-term average NDVI images and of a dry and wet year NDVI image. These values were then used to create refugia and non-refugia maps using ArcGIS Pro. Land cover data from Sentinel-2 and a digital elevation model (DEM), using the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), were plotted in ArcGIS Pro to determine the slope and aspect of the area. Global Ecosystems Dynamics Investigation (GEDI) data were used to look at forest height of the study area, and the distribution of forest height, slope, aspect, and elevation were plotted to determine their probability densities in refugia and non-refugia areas. Results of this study show increased biomass in refugia areas. This suggests that conservation practices are crucial to aid in the preservation of biodiversity and biomass within these refugia areas.

      Jayce Crayne
      Site-Based Observations of a Saharan Dust Storm’s Impacts on Evapotranspiration in North-Central Florida
      Jayce Crayne
      Saharan dust storms serve an important role in the western Atlantic’s climate in their contribution to Earth’s radiation budget, modulating sea surface temperatures (SSTs), fertilizing ecosystems, and suppressing cloud and precipitation patterns (Yuan et al., 2020). However, Saharan dust storms are expected to become less frequent in this region as SSTs continue to rise (Yuan et al., 2020). Predicting the climate response to this change requires a keen understanding of how the presence of these storms affect evapotranspiration (ET) and its indicators. This study utilizes site-based observational data from an AmeriFlux tower near Gainesville, FL recorded during a large dust storm in late June 2020. The storm’s progression was documented using satellite imagery from Aqua and Terra and aerosol optical depth (AOD) measurements from an Aerosol Robotic Network (AERONET) station co-located with the AmeriFlux tower. Indicators of ET such as surface air temperature, vapor pressure deficit, photosynthetic photon flux density, and net radiation were analyzed. Findings were compared to modeled ET and latent energy flux reanalysis data provided by the Global Land Data Assimilation System (GLDAS). Both model simulations and on-site observations support that ET decreased during the days dust concentrations were heaviest and for a short time thereafter. Cloud cover data adopted from meteorological aerodrome reports (METARs) provided by an automated surface observing system (ASOS) located in Gainesville showed that clouds were not a major contributor in decreasing ET during the days of heaviest dust. The results of this study show a considerable decrease in ET as a result of dust aerosols. Further research is necessary to determine whether changes in ET due to Saharan dust storms are significant enough to alter climates in the western Atlantic and, if so, what the climate response will be if the frequency of storms decreases.

      Brandon Wilson
      Predicting 2025 and 2028 dNBR and dNDIV for Csarf Smith River Complex / Evaluating the Effects of 2019 California Wildfire Fund
      Brandon Wilson
      Biodiverse regions across California remain vulnerable to harmful wildfires year round. Quantifying and measuring these regions’ wildfire resilience is necessary for understanding where/how to allocate environmental resources. Several ecological wildfire studies have been conducted utilizing artificial intelligence and remote sensing to analyze and predict biodiversity damage across wildfire prone regions, including Northern Algeria and Arkansas, USA. The current case study aims to analyze biodiversity damage from the 2023 Csarf Smith River Complex Fire in Six Rivers National Forest, California and predict the difference in Normalized Burn Ratio (dNBR) and difference in Normalized Difference Vegetation Index (dNDVI) for 2025 and 2028 using remote-sensing-based random forest (RF) regression. Furthermore, to observe, holistically, a practical method California has implemented to address state-wide wildfire damage, the 2019 California Wildfire Fund (AB 1054 and AB 111) was evaluated using the synthetic control method (SCM). For this case study, remote sensing data from the United States Geological Survey (USGS) and NASA (Landsat 9 Satellite C2 L2, TerraClimate and the Land Data Assimilation System) were utilized for processing relevant spectral indexes for the RF. Data from NOAA, Energy Information Agency, International Monetary Fund and Bureau of Economic Analysis were utilized as synthetic control datasets to evaluate the effects of the 2019 California Wildfire Fund. Elevated topography in this study area is susceptible to high severity burn effects, while less elevated topography burns less. This result affected dNBR and dNDVI predictions as elevated areas seemingly did not have strong resilience to rampant burns. This demonstrates a direct correlation to potential lower transpiration rates for elevated areas, warranting further analysis. Results of low variance, post-treatment, between the treated unit and the synthetic control unit, poses concern for the positive effect of the 2019 Wildfire Fund.

      Carrie Hashimoto
      Describing changes in evapotranspiration following the 2020 Creek Fire in the southern Sierra Nevada
      Carrie Hashimoto
      Climatic warming and high tree density have caused larger and more severe wildfires to occur in western United States forests over time. Wildfires affect both the hydrology and ecology of forests via alterations to the water balance (e.g., evapotranspiration, streamflow, infiltration, and more) and could shift vegetation communities and subsequent ecosystem structure and function. This project explores ecological characteristics of a landscape that predict the extent to which the Creek Fire in the southern Sierra Nevada has affected evapotranspiration. Strides in understanding of consequential evapotranspiration changes can create pathways to address emerging forest health challenges posed by similar western fires. For analysis, various remote sensing and modeled data were collected from OpenET, the North American Land Data Assimilation System, TerraClimate, Harmonized LandSat Sentinel-2 data, and the Shuttle Radar Topography Mission. Multiple linear regression and generalized additive models were constructed. Relative change in evapotranspiration served as the response variable. Model covariates included average temperature, total precipitation in the preceding months, average soil moisture, elevation, slope, aspect, northness, latitude, pre-fire normalized difference vegetation index (NDVI), and post-fire change in normalized burn ratio (dNBR). Best subset selection with cross validation demonstrated minimization of cross-validation error with a 7-covariate model. This reduced model yields lower complexity and more interpretability while sustaining an adjusted R2 of 0.626, compared to the full model’s adjusted R2 of 0.663. A reduced generalized additive model (GAM) with interaction terms drawn from the linear model variable selection demonstrated an adjusted R2 of 0.695, indicating a better fit that comes at the cost of reduced interpretability and higher computational requirements than the linear models. The goal of this work is to disentangle environmental indicators of post-fire evapotranspiration change, such that predictive modeling of future wildfire impacts on evapotranspiration can be achieved.


      Return to 2024 SARP Closeout Share
      Details
      Last Updated Nov 22, 2024 Related Terms
      General Explore More
      8 min read SARP East 2024 Ocean Remote Sensing Group
      Article 21 mins ago 10 min read SARP East 2024 Atmospheric Science Group
      Article 21 mins ago 11 min read SARP East 2024 Terrestrial Fluxes Group
      Article 22 mins ago View the full article
    • By NASA
      11 min read
      Preparations for Next Moonwalk Simulations Underway (and Underwater)
      Return to 2024 SARP Closeout Faculty Advisors:
      Dr. Lisa Haber, Virginia Commonwealth University
      Dr. Brandon Alveshere, Virginia Commonwealth University
      Dr. Chris Gough, Virginia Commonwealth University
      Graduate Mentor:
      Mindy Priddy, Virginia Commonwealth University

      Mindy Priddy, Graduate Mentor
      Mindy Priddy, graduate mentor for the 2024 SARP Terrestrial Fluxes group, provides an introduction for each of the group members and shares behind-the scenes moments from the internship.

      Angelina De La Torre
      Using NDVI as a Proxy for GPP to Predict Carbon Dioxide Fluxes
      Angelina De La Torre
      Climate change, driven primarily by greenhouse gases, poses a threat to the future of our planet. Among these gases is carbon dioxide (CO₂), which has a much longer atmospheric residence time compared to other greenhouse gases. One potential factor in reducing atmospheric CO₂ enrichment is plant productivity. Gross Primary Productivity (GPP) estimates the amount of CO₂ fixed during photosynthesis. The Normalized Difference Vegetation Index (NDVI) provides insight into the health of an ecosystem by measuring the density and greenness of vegetation. Therefore, it can be inferred that there is a relationship between NDVI and GPP, as greener plants are likely more productive. In this study, we used NDVI as a proxy for GPP and analyzed the effect NDVI had on CO₂ fluxes during California’s wet season between January and March 2023 in a restored tidal freshwater wetland. GPP and CO₂ flux data were obtained from the Dutch Slough AmeriFlux tower in Oakley, California. Landsat data were used to calculate the average NDVI. The influence of NDVI on GPP was assessed using linear regression. A second linear regression was then performed using NDVI and CO₂ flux, of which GPP is one component. We anticipate that wetlands with greater vegetation density will have lower CO₂ emissions.

      Because Landsat data scans in 16-day intervals, daily variation in NDVI could not be observed. This translates to a frequency discrepancy between the Landsat and AmeriFlux data, as AmeriFlux towers measure in half-hour intervals. Additionally, the wet season represented was limited by data availability, as the data before 2023 were unavailable. Despite data limitations in this study, the outlined process could be repeated in various wetland and climate classifications for further analysis of a larger sample size. This study could assist in developing strategies to increase CO₂ sequestration in an attempt to slow the effects of climate change.

      Samarth Jayadev
      Using Machine Learning to Assess Relationships between NDVI and Net Carbon Exchange During the COVID-19 Pandemic
      Samarth Jayadev
      Understanding the movement of carbon between Earth’s land surface and atmosphere is essential for ecosystem monitoring, creating climate change mitigation strategies, and assessing the carbon budget on national to global scales. Measures of greenness serve as indicators of processes such as photosynthesis that control carbon exchange and are vital in modeling of carbon fluxes. NASA’s Orbiting Carbon Observatory (OCO-2) provides high quality measurements of column-averaged CO₂ concentrations that can be used to derive net carbon exchange (NCE), a measure of CO₂ flux between terrestrial ecosystems and the atmosphere.
      From OCO-2, NCE data collected at the land nadir, land glint satellite position combined with in situ sampling can provide accurate measurements on a 1°x1° scale suitable for carbon flux characterization across the contiguous United States (CONUS). Normalized difference vegetation index (NDVI), which ranges from -1 to +1, measures the greenness of vegetation, serving as an indicator of plant density and health. This can help to understand ecosystem to carbon-cycle interactions and be leveraged for determining patterns with NCE. We examined the relationship between NDVI and NCE across CONUS during 2020 using Gradient Boosting Decision Trees (GBDT) which specialize in classifying and predicting non-linear relationships. This algorithm takes multiple weak learners (decision trees) and combines their predictions in an iterative ensemble method to improve prediction accuracy. Feature and permutation importance tests found that January and August (trough and peak NDVI, respectively) were the highest weighted predictor variables related to NCE. The dataset was split in a 90% training 10% test ratio across latitude/longitude grid cells to assess and verify model performance. Using the mean squared error loss function and hyperparameters with optimal estimators, tree depth, sample split, and learning rate the algorithm was able to converge the test predictions to match the deviance of the training data. The gradient boosting model can be applied to different months and years of NDVI/NCE to further explore these relationships or a multitude of research questions. Further studies should consider integrating land use and land cover change variables such as bare land and urbanization to improve predictions of NCE.

      Makai Ogoshi
      Deep-learning Derived Spaceborne Canopy Structural Metrics Predict Forest Carbon Fluxes
      Makai Ogoshi
      Terrestrial and airborne lidar data products describing canopy structure are potent predictors of forest carbon fluxes, but whether satellite data products produce similarly robust indicators of canopy structure is not known. The assessment of contemporary spaceborne lidar and other remote sensing data products as predictors of carbon fluxes is crucial to next generation instrument and data product design and large-spatial scale modeling. We investigated relationships between deciduous broadleaf forest canopy structure, derived from deep-learning models created with lidar data from GEDI and optical imagery from Sentinel-2, and forest carbon exchange. These included comparisons to in-situ continuous net ecosystem exchange (NEE), gross primary production (GPP), and net primary production (NPP). We find that the mean  canopy height from the gridded spaceborne product has a strong correlation with forest NPP, similar to prior analysis with ground-based lidar (portable canopy lidar; PCL). For comparison to NPP, heights taken from the gridded spaceborne product were compared by overlapping the product with nine terrestrial forest sites from the National Ecological Observatory Network (NEON). We used standard deviation of canopy height as a measure of canopy structural complexity. Complexity derived from the gridded spaceborne product does not show the same strong correlation with NPP as found when using PCL. Mean annual GPP and NEE across five years were compared to the gridded spaceborne product at six Fluxnet2015-tower sites with continuous, gap-filled carbon flux data. When compared to in-situ flux tower data, neither mean canopy height nor structural complexity strongly correlate to annual NEE or GPP. Primarily, the finding that derived spaceborne products exhibit a strong correlation between forest canopy height and NPP will advance global-scale application of forest-carbon flux predictions. Secondarily, a variety of limitations highlight shortcomings in the current terrestrial flux data network. A small number of available study sites, both spatially and temporally, and lack of resolution in vertical complexity of canopy structure both contribute to uncertainty in assessing the relationships to NEE and GPP.

      Sebastian Reed
      Porewater Methane Concentrations Vary Significantly Across A Freshwater Tidal Wetland
      Sebastian Reed
      Methane is a potent greenhouse gas that is over 80 times more powerful than CO₂ at trapping heat and accounts for an estimated 30% of global temperature rise associated with climate change. The largest natural source of methane worldwide is wetlands. Despite the role of methane in driving climate change, the magnitude of global annual wetland methane flux remains highly uncertain. This study analyzes the effects of greenness (assessed using Normalized Difference Vegetation Index; NDVI), plant species composition, rooting depth, atmospheric methane concentration, and plant longevity on porewater methane concentration at the Kimages Rice Rivers Center tidal freshwater wetland. Samples for atmospheric and porewater concentrations were conducted in situ in June 2024. For each sampling location (n = 23) we collected whole air samples (WAS) 2m above the marsh surface and porewater samples 5cm below the marsh surface. We visually assessed species composition at each sample location, with 12 species of wetland plants present overall. We used the TRY plant database to find the rooting depth, leaf nitrogen content, and lifespan of each species. Drone multispectral data from 2023 was used to estimate NDVI values. These variables were compared to the pore water methane concentration via stepwise linear regression. Leaf N content, NDVI, plant species, and WAS sampling did not show statistically significant correlation to porewater methane concentration. Rooting depth showed a slight positive correlation with porewater methane (alpha = 0.1, p = 0.08, R^2 = 0.1). Samples with only perennial plants (as opposed to annual plants) had a higher mean value of porewater methane (p = 0.1). Analyzing porewater methane provides insight as to what wetland components affect methanogenesis and methane release, which aids in assessing which plant functional traits are most responsible for driving or mitigating climate change. Results from this study and future research in this area has the potential to more accurately assess how methane cycles through wetlands to the atmosphere.

      Nohemi Rodarte
      Understanding the vertical profile of CO₂ concentration: How carbon dioxide levels change with altitude
      Nohemi Rodarte
      Carbon dioxide (CO₂) is one of the main greenhouse gasses that contribute to global warming.While the relationship between CO₂ concentrations and land cover types, such as forests and urban areas, is well documented, there is limited knowledge of how CO₂ concentrations vary with altitude at fine spatial scales. Guided by our hypothesis that CO₂ levels vary with altitude and increase with elevation, we used airborne data collected from the B200 aircraft, which flew at different altitudes (400 to 1200 feet) above the urban area of Hopewell, Virginia, between 9:40 AM and 10:40 AM. We analyzed the CO₂ concentrations recorded by the flight to obtain the median and range for each 100 feet of altitude. Our results reveal that carbon dioxide concentrations varied significantly across the range of altitudes investigated. Within the area studied, CO₂ concentrations were found to range between 410 and 470 ppm. The distribution of these concentrations along the altitude gradient shows a bimodal pattern, with notable peaks at altitudes of 700 to 800 feet and 1100 to 1200 feet. Although CO₂ levels were present at all measured altitudes, there was a noticeable drop in the mean concentration at 800 feet,which then stabilized until reaching 1,000 feet before rising again. This pattern indicates that the concentrations of this greenhouse gas are not uniformly distributed with altitude, but rather vary significantly, showing higher concentrations at certain elevations and lower concentrations at others. The CO₂ distribution fluctuates with altitude, showing higher or lower levels at specific heights rather than a smooth gradient, indicating that altitude impacts CO₂ concentrations. While we did not identify the drivers of this change, future studies could evaluate how factors such as surface emissions, atmospheric mixing, and local conditions may contribute to vertical CO₂ profiles, since the altitudes we considered in this research are within the troposphere.

      Camille Shaw
      Linking NDVI with CO₂ and CH₄ Fluxes: Insights into Vegetation and Urban Source-Sink Dynamics in the Great Dismal Swamp
      Camille Shaw
      In recent years, carbon dioxide, methane, and other greenhouse gases have gained attention because of their contribution to the rise in Earth’s global mean temperature. Methane and carbon dioxide have various sources and sinks, but an expanding array of sources have created a need to assess ongoing change in carbon balance. This study aims to quantify the relationship between Normalized Difference Vegetation Index, or NDVI, and methane and carbon dioxide fluxes. We measured carbon dioxide and methane concentrations within the boundary layer using the PICARRO instrument, focusing on the Great Dismal Swamp, a forested wetland, and surrounding areas in the Eastern Mid-Atlantic Region. Data collection occurred at various times of day and along different flight paths in 2016, 2017, and 2024, with each year representing data from a single season, either spring or fall, for temporal analysis. We calculated methane and carbon dioxide fluxes along the flight paths using airborne eddy covariance, a method for capturing accurate flux measurements while accounting for the mixing of gases in the boundary layer caused by heat. Additionally, we calculated NDVI for this area using NASA’s Landsat 8 and 9 satellite imagery. Analysis of the afternoon flight data revealed a negative linear correlation between NDVI and carbon dioxide flux. Urban areas, characterized by low NDVI, exhibit a positive carbon dioxide flux as a consequence of emissions from vehicles, while forested areas, with high NDVI, show a negative carbon dioxide flux because of photosynthesis. In contrast, methane flux shows minimal correlation with NDVI. The lack of correlation arises because forested wetlands, with high NDVI, emit substantial amounts of methane, while urban areas, despite having low NDVI, still produce significant methane emissions from landfills and industrial activities. Future research could further investigate how seasonal and diurnal variations influence the correlations between NDVI and greenhouse gases by collecting comprehensive data across all seasons within a given year and at various times of the day.

      Return to 2024 SARP Closeout Share
      Details
      Last Updated Nov 22, 2024 Related Terms
      General Explore More
      8 min read SARP East 2024 Ocean Remote Sensing Group
      Article 21 mins ago 10 min read SARP East 2024 Atmospheric Science Group
      Article 21 mins ago 10 min read SARP East 2024 Hydroecology Group
      Article 21 mins ago View the full article
  • Check out these Videos

×
×
  • Create New...