Jump to content

The Marshall Star for October 23, 2024


NASA

Recommended Posts

  • Publishers
19 Min Read

The Marshall Star for October 23, 2024

An illustration of a black hole with a dark circle surrounded by light discs.

Editor’s Note: Starting Nov. 4, the Office of Communications at NASA’s Marshall Space Flight Center will no longer publish the Marshall Star on nasa.gov. The last public issue will be Oct. 30. To continue reading Marshall news, visit nasa.gov/marshall.

Habitation Systems Business Unit Spotlight: Living and Working in Space

For centuries, humans have dreamed of the ability to live safely on the Moon and Mars. At NASA’s Marshall Space Flight Center, team members supporting habitation systems development bring that dream closer to reality by envisioning and shaping humanity’s future in deep space and on the surface of other worlds.

Marshall’s Habitation Systems business unit – the center’s featured organization for October – develops the next generation of habitation systems to make living and working in space and on planetary bodies possible. These efforts are carried out through the Habitation Systems Development Office, in which the team works across programmatic and engineering organizations to support formulation activities for planetary surface habitation (Moon and Mars), transit habitats for deep space exploration, and the Gateway program. In addition, the Marshall team collaborates with commercial partners on future habitation concept development and risk reduction activities through NextSTEP Appendix A: Habitation Systems and Reimbursable Space Act Agreements.   

Seth Bell
Seth Bell
NASA

Seth Bell is currently the technical monitor for NASA’s commercial partner Sierra Space. Sierra has executed both full scale and subscale inflatable habitat burst tests at Marshall’s East Test Area. Bell has worked as a subsystem manager for the Mars Ascent Vehicle and as a system’s engineer and Engineering Directorate integrator.

“I am excited to eventually see softgood inflatables in low Earth orbit,” Bell said. “Seeing the success of the many teams working in this office is exciting, especially after developing so many lasting relationships and putting so much time and energy into this work.”

Yancy Young
Yancy Young
NASA

Since joining NASA in 2008, Yancy Young has served in multiple positions, including manager of several International Space Station research projects and Launch Package manager for Gateway Co-manifested Payloads. Currently, Young is the technical monitor for Boeing efforts under NASA’s NextSTEP Appendix A Broad Agency Announcement (BAA) for the development of deep space habitation concepts.

“I love being a part of laying the foundation for long term deep space exploration,” Young said.

Boeing’s current focus is a Design Analysis Cycle investigating the benefits and challenges of using composite materials in a pressurized Lunar Surface Habitat.

Brooke Thornton
Brooke Thornton
NASA

In her 25-plus years at NASA, Brooke Thornton has worked on everything from ionized space radiation analysis to Earth observing satellites. Currently, Thornton is the industry engagement manager for the Habitation Systems Development Office and Strategy and Architecture Office. Thornton manages NextSTEP-2 Appendix A-Habitation Systems and Appendix R-Logistics and Mobility Systems BAA. In addition, Thornton fosters collaboration between industry and NASA for the Moon to Mars mission.

“I am excited about working with industry to develop the elements and concepts of operations for humans to live on the Moon and beyond,” Thornton said.

› Back to Top

Team Members Enjoy Marshall Exchange BBQ Fest

Joseph Pelfrey, center, director of NASA’s Marshall Space Flight Center, talks with team members during the BBQ Fest hosted by the Marshall Exchange on Oct. 21. The event was held on the walking trail behind the Wellness Center and was open to team members, their family members, and retirees. "My thanks to those who came out to this year's BBQ – and especially to those who helped make it happen,” Pelfrey said. “I could not have asked for better weather or a better group of people to spend the afternoon with. It was great to see everyone's families join us on site to celebrate the hard work our teams have put in this year.”

Joseph Pelfrey, center, director of NASA’s Marshall Space Flight Center, talks with team members during the BBQ Fest hosted by the Marshall Exchange on Oct. 21. The event was held on the walking trail behind the Wellness Center and was open to team members, their family members, and retirees. “My thanks to those who came out to this year’s BBQ – and especially to those who helped make it happen,” Pelfrey said. “I could not have asked for better weather or a better group of people to spend the afternoon with. It was great to see everyone’s families join us on site to celebrate the hard work our teams have put in this year.” (NASA/Charles Beason)

Children play on an inflatable at the BBQ Fest with a space shuttle inflatable in the background.

Children play on an inflatable at the BBQ Fest with a space shuttle inflatable in the background. (NASA/Charles Beason)

Marshall team members participate in Bingo during the BBQ hosted by the Marshall Exchange.

Marshall team members participate in Bingo during the BBQ hosted by the Marshall Exchange. (NASA/Charles Beason)

› Back to Top

Tony Clark Named Deputy Director of Marshall’s Engineering Directorate

Tony Clark has been named to the Senior Executive Service position of deputy director of the Engineering Directorate at NASA’s Marshall Space Flight Center, effective immediately. In this role, Clark will be help lead the center’s largest organization, comprised of more than 2,500 civil service and contractor personnel, who design, test, evaluate, and operate flight hardware and software associated with Marshall-developed space transportation and spacecraft systems, science instruments, and payloads.

Tony Lee Clark.
Tony Clark has been named to the Senior Executive Service position of deputy director of the Engineering Directorate at NASA’s Marshall Space Flight Center.
NASA

Clark previously served as deputy director of the Space Systems Department at Marshall from 2021-2024 and served as acting director in 2024. In this role, Clark led the design, development, assembly, integration, testing, and delivery of flight, ground, prototype, and development products for NASA human spaceflight programs, science investigations, and exploration initiatives. He aided in the oversight of an annual budget of approximately $70 million and helped manage a diverse, highly technical workforce of approximately 660 civil service employees and contractors.

Over his three decades of service to NASA, Clark has held numerous key leadership roles, bringing a wealth of technical and supervisory experience to Marshall’s broad range of engineering endeavors. He served as manager of the vehicle equipment area in Johnson Space Center’s Vehicle Systems Integration Office of the Gateway Program from 2018-2021. He was also manager of the Engineering Resource Management Office in Marshall’s Engineering Directorate from 2014-2018, tasked with leading and coordinating resources among eight engineering departments, laboratories and offices staffed by more than 2,300 civil service and contract personnel.

He was acting deputy manager of the Engineering Directorate’s Spacecraft and Vehicle Systems Department from February 2014 to October 2014. Prior to that, Clark was chief of the directorate’s Electrical Integration and Fabrication Division from 2007-2014, and chief of the Electromagnetic Environmental Effects and Electrical Integration Branch from 2004-2007. He joined Marshall in September 1991 as an electromagnetic environmental effects engineer.

Clark earned a bachelor’s degree in electrical engineering from Tennessee Technological University in Cookeville in 1989 and a master’s degree in electrical engineering from The Ohio State University in Columbus in 1991.

Among his many professional awards and honors, Clark received the NASA Exceptional Achievement Medal in 2010 for his work on the Ares IX, the launch vehicle which informed development of NASA’s new rocket, the Space Launch System. He also received a Silver Snoopy award in 1999, reflecting outstanding service and the highest dedication to safe human spaceflight.

Clark was a founding member in 2004 of the Huntsville Chapter of the Institute of Electrical and Electronic Engineers’ Electromagnetic Compatibility Society.

› Back to Top

I Am Artemis: Sarah Ryan

A passion for puzzles, problem-solving, and propulsion led Sarah Ryan – a native of Columbus, Ohio – to her current position as Raptor engine lead for NASA’s HLS (Human Landing System) insight team at NASA’s Marshall Space Flight Center. The SpaceX Raptor rocket engine powers the company’s Starship and Super Heavy rocket. SpaceX will land astronauts on the Moon for NASA’s Artemis III and Artemis IV missions using the Starship HLS. NASA’s Artemis campaign aims to land the first woman, first person of color, and first international partner astronaut on the Moon.

NASA Human Landing System Program Raptor engine insight lead Sarah Ryan poses in front of a model of SpaceX’s Starship human landing system. Sarah is in a navy shirt and khaki pants. She poses with her arms crossed in front of her chest. The black and white lander is just over her right shoulder.
NASA’s Sarah Ryan is the Raptor engine lead for NASA’s HLS (Human Landing System) Program at NASA’s Marshall Space Flight Center. “With Artemis, we’re moving beyond what NASA did with Apollo and that’s really inspiring, especially to our younger workforce. We’re trying to push farther and it’s really going to drive a lot of technology development on the way there,” Ryan said. “This is a dream come true to be working on Artemis and solving problems so humanity can get back to the Moon then on to Mars.”
NASA/Ken Hall

“My team looks at how the components of the Raptor engine work together. Then, we evaluate the performance of the full system to make sure it will accomplish the NASA HLS and Artemis missions,” Ryan said. “I get to see lots of pieces and parts of the puzzle and then look at the system as a whole to make sure it meets NASA’s needs.”

While earning a bachelor’s degree from Case Western Reserve University in Cleveland with a dual major in aerospace engineering and mechanical engineering, Ryan had an internship at Marshall, working on a payload for a science mission onboard the International Space Station.

After working for a year on satellite design, Ryan returned to Marshall. She noted that the opportunity to work in Marshall’s Engine Systems branch, to be involved with pushing technology forward, and to work on Artemis, really drew her back to NASA. Ryan later earned a master’s degree in aerospace systems from the University of Alabama in Huntsville.

When not occupied with rocket engine development, Ryan likes to work on quieter hobbies in her free time, including reading, board games, crocheting, and solving all manner of puzzles – crosswords, number games, word games, and more. Her interest for solving puzzles carries over into her work on the Raptor rocket engines for HLS.

“My favorite tasks are the ones that most resemble a puzzle,” Ryan said. “If we’re investigating an issue and have a lot of information to assess, I love putting all the pieces together and figuring out what happened, why, and the path forward. I enjoy digging into the data and solving those puzzles.”

With Artemis, NASA will explore more of the Moon than ever before, learn how to live and work away from home, and prepare for future human exploration of Mars. NASA’s SLS (Space Launch System) rocket, exploration ground systems, and Orion spacecraft, along with the HLS, next-generation spacesuits, Gateway lunar space station, and future rovers are NASA’s foundation for deep space exploration.

› Back to Top

I Am Artemis: Casey Wolfe

While precision, perseverance, and engineering are necessary skills in building a Moon rocket, Casey Wolfe knows that one of the most important aspects for the job is teamwork.

“Engineering is vital, but to get this type of work done, you need to take care of the human element,” said Wolfe, the assistant branch chief of the advanced manufacturing branch in the Materials and Processes Laboratory at NASA’s Marshall Space Flight Center.

Casey Wolfe is developing and producing the next generation payload adapter for NASA’s SLS (Space Launch System) super-heavy lift rocket. The adapter is made with some of the world’s most advanced composite manufacturing techniques.
Casey Wolfe is developing and producing the next generation payload adapter for NASA’s SLS (Space Launch System) super-heavy lift rocket. The adapter is made with some of the world’s most advanced composite manufacturing techniques.
NASA/Sam Lott

Together with her team, Wolfe is developing and producing the next generation payload adapter for NASA’s SLS (Space Launch System) super-heavy lift rocket. The adapter is made with some of the world’s most advanced composite manufacturing techniques.

Wolfe’s work integrates the technical day-to-day operations and personnel management of the composites manufacturing team and additive manufacturing team, balancing production of SLS hardware with the creation of new engines using the latest manufacturing technologies. 

“A lot of my day to day is in managing our two teams, making connections, building relationships, and making sure people feel supported,” Wolfe said. “I conduct individual tag ups with each team member so we can be proactive about anticipating and addressing problems.”

Wolfe grew up in Huntsville, a place known as the “Rocket City,” but it wasn’t until she visited a job fair while studying at Auburn University for a polymer and fiber engineering degree that she began to consider a career at Marshall. Wolfe applied for and was selected to be a NASA intern through the Pathways Program, working in the non-metallic materials branch of the Materials and Processes Laboratory.

Wolfe supported a coating system for electrostatic discharge on the first uncrewed test flight of the Orion spacecraft. Launching Dec. 5, 2014, Orion traveled to an altitude of 3,600 miles, orbited Earth twice, and splashed down in the Pacific Ocean. It was during her internship that Wolfe realized how inspirational it felt to be treated like a vital part of a team.

“The SLS program gave everyone permission to sign the hardware, even me – even though I was just an intern,” Wolfe said. “It was impactful to me, knowing that something I had worked on had my name on it and went to space.” 

Since being hired by NASA, Wolfe’s work has supported development of the Orion stage adapter diaphragms for Artemis II and Artemis III, and the payload adapters for Artemis IV and beyond. The first three Artemis flights use the SLS Block 1 rocket variant, which can send more than 27 metric tons (59,500 pounds) to the Moon in a single launch. Beginning with Artemis IV, the SLS Block 1B variant will use the new, more powerful exploration upper stage to enable more ambitious missions to deep space, with the cone-shaped payload adapter situated atop the rocket’s exploration upper stage. The new variant will be capable of launching more than 38 metric tons (84,000 pounds) to the Moon in a single launch.

“While the engineering development unit of the payload adapter is undergoing large-scale testing, our team is working on the production of the qualification article, which will also be tested,” Wolfe said. “Flight components should be starting fabrication in the next six months.”

When Wolfe isn’t working, she enjoys hiking, gardening, and hanging out with her dogs and large family. Recently, she signed another piece of SLS hardware headed to space: the Orion stage adapter for the second Artemis mission.

With as many responsibilities as Wolfe juggles, it’s easy to lose sight of her work’s impact. “I work in the lab around the hardware all the time, and in many ways, it can become very rote,” she said.

But Wolfe won’t forget what she saw one evening when she worked late: “Everybody was gone, and as I walked past the launch vehicle stage adapter, there were two security guards taking pictures of each other in front of it. It was one of those things that made me step back and reflect on what my team accomplishes every day: making history happen.”

NASA is working to land the first woman, first person of color, and its first international partner astronaut on the Moon under Artemis. SLS is part of NASA’s backbone for deep space exploration, along with the Orion spacecraft, supporting ground systems, advanced spacesuits and rovers, the Gateway in orbit around the Moon, and commercial human landing systems. SLS is the only rocket that can send Orion, astronauts, and supplies to the Moon in a single launch.

› Back to Top

NASA’s IXPE Helps Researchers Determine Shape of Black Hole Corona

By Rick Smith

New findings using data from NASA’s IXPE (Imaging X-ray Polarimetry Explorer) mission offer unprecedented insight into the shape and nature of a structure important to black holes called a corona.

A corona is a shifting plasma region that is part of the flow of matter onto a black hole, about which scientists have only a theoretical understanding. The new results reveal the corona’s shape for the first time, and may aid scientists’ understanding of the corona’s role in feeding and sustaining black holes.

An illustration of a black hole with a dark circle surrounded by light discs.
This illustration of material swirling around a black hole highlights a particular feature, called the “corona,” which can be seen as a purple haze floating above the underlying accretion disk and extending slightly inside its inner edge. The material within the inner accretion disk is incredibly hot and would glow with a blinding blue-white light, but here has been reduced in brightness to make the corona stand out with better contrast. Its purple color is purely illustrative, standing in for the X-ray glow that would not be obvious in visible light. The warp in the disk is a realistic representation of how the black hole’s immense gravity acts like an optical lens, distorting our view of the flat disk that encircles it.
NASA/Caltech-IPAC/Robert Hurt

Many black holes, so named because not even light can escape their titanic gravity, are surrounded by accretion disks, debris-cluttered whirlpools of gas. Some black holes also have relativistic jets – ultra-powerful outbursts of matter hurled into space at high speed by black holes that are actively eating material in their surroundings.

Less well known, perhaps, is that snacking black holes, much like Earth’s Sun and other stars, also possess a superheated corona. While the Sun’s corona, which is the star’s outermost atmosphere, burns at roughly 1.8 million degrees Fahrenheit, the temperature of a black hole corona is estimated at billions of degrees.

Astrophysicists previously identified coronae among stellar-mass black holes – those formed by a star’s collapse – and supermassive black holes such as the one at the heart of the Milky Way galaxy.

“Scientists have long speculated on the makeup and geometry of the corona,” said Lynne Saade, a postdoctoral researcher at NASA’s Marshall Space Flight Center and lead author of the new findings. “Is it a sphere above and below the black hole, or an atmosphere generated by the accretion disk, or perhaps plasma located at the base of the jets?”

Enter IXPE, which specializes in X-ray polarization, the characteristic of light that helps map the shape and structure of even the most powerful energy sources, illuminating their inner workings even when the objects are too small, bright, or distant to see directly. Just as we can safely observe the Sun’s corona during a total solar eclipse, IXPE provides the means to clearly study the black hole’s accretion geometry, or the shape and structure of its accretion disk and related structures, including the corona.

“X-ray polarization provides a new way to examine black hole accretion geometry,” Saade said. “If the accretion geometry of black holes is similar regardless of mass, we expect the same to be true of their polarization properties.”

IXPE demonstrated that, among all black holes for which coronal properties could be directly measured via polarization, the corona was found to be extended in the same direction as the accretion disk – providing, for the first time, clues to the corona’s shape and clear evidence of its relationship to the accretion disk. The results rule out the possibility that the corona is shaped like a lamppost hovering over the disk. 

The research team studied data from IXPE’s observations of 12 black holes, among them Cygnus X-1 and Cygnus X-3, stellar-mass binary black hole systems about 7,000 and 37,000 light-years from Earth, respectively, and LMC X-1 and LMC X-3, stellar-mass black holes in the Large Magellanic Cloud more than 165,000 light-years away. IXPE also observed a number of supermassive black holes, including the one at the center of the Circinus galaxy, 13 million light-years from Earth, and those in galaxies NGC 1068 and NGC 4151, 47 million light-years away and nearly 62 million light-years away, respectively.

Stellar mass black holes typically have a mass roughly 10 to 30 times that of Earth’s Sun, whereas supermassive black holes may have a mass that is millions to tens of billions of times larger. Despite these vast differences in scale, IXPE data suggests both types of black holes create accretion disks of similar geometry.

That’s surprising, said Marshall astrophysicist Philip Kaaret, principal investigator for the IXPE mission, because the way the two types are fed is completely different.

“Stellar-mass black holes rip mass from their companion stars, whereas supermassive black holes devour everything around them,” he said. “Yet the accretion mechanism functions much the same way.”

That’s an exciting prospect, Saade said, because it suggests that studies of stellar-mass black holes – typically much closer to Earth than their much more massive cousins – can help shed new light on properties of supermassive black holes as well. The team next hopes to make additional examinations of both types.

Saade anticipates there’s much more to glean from X-ray studies of these behemoths. “IXPE has provided the first opportunity in a long time for X-ray astronomy to reveal the underlying processes of accretion and unlock new findings about black holes,” she said.

The complete findings are available in the latest issue of The Astrophysical Journal.

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

› Back to Top

Michoud Gets a Rare Visitor

The night sky goes from blue to pink as you look from top to bottom. In the middle is a comet; it looks like a relatively bright yellow dot with a long, diffuse yellow tail. Some stars are visible in the blue portion of the sky.

The Oort Cloud comet, called C/2023 A3 Tsuchinshan-ATLAS, passes over Southeast Louisiana near New Orleans, home of NASA’s Michoud Assembly Facility on Oct. 13. The comet is making its first appearance in documented human history; it was last seen in the night sky 80,000 years ago. The Tsuchinshan-ATLAS comet made its first close pass by Earth in mid-October and will remain visible to viewers in the Northern Hemisphere just between the star Arcturus and planet Venus through early November. Eric Bordelon, a photographer for Michoud, captured the image, which was featured as NASA’s image of the day. “On Sunday evening I decided to head out to find the comet I’ve read so much about,” Bordelon said. “Struggling at first to see it, once my eyes adjusted to the darkness I could faintly see it. I pulled my camera out and set up a tripod, with a longer exposure around six seconds I was able to capture this shot with a single frame. The far off setting sun made a beautiful color gradient in the dark sky with the other stars just beginning to appear.” Read more about the comet. (NASA/Eric Bordelon)

› Back to Top

Hubble Captures New View of Galaxy M90

A new NASA/ESA Hubble Space Telescope image features the striking spiral galaxy Messier 90 (M90, also NGC 4569), located in the constellation Virgo. In 2019, Hubble released an image of M90 created with Wide Field and Planetary Camera 2 (WFPC2) data taken in 1994, soon after its installation. That WFPC2 image has a distinctive stair-step pattern due to the layout of its sensors. Wide Field Camera 3 (WFC3) replaced WFPC2 in 2009 and Hubble used WFC3 when it turned its aperture to Messier 90 again in 2019 and 2023. That data resulted in this stunning new image, providing a much fuller view of the galaxy’s dusty disk, its gaseous halo, and its bright core.

This eye-catching image offers us a new view of the spiral galaxy Messier 90 from the NASA/ESA Hubble Space Telescope.
This eye-catching image offers us a new view of the spiral galaxy Messier 90 from the NASA/ESA Hubble Space Telescope.
ESA/Hubble & NASA, D. Thilker, J. Lee and the PHANGS-HST Team

The inner regions of M90’s disk are sites of star formation, seen here in red H-alpha light from nebulae. M90 sits among the galaxies of the relatively nearby Virgo Cluster, and its orbit took M90 on a path near the cluster’s center about three hundred million years ago. The density of gas in the inner cluster weighed on M90 like a strong headwind, stripping enormous quantities of gas from the galaxy and creating the diffuse halo we see around it. This gas is no longer available to form new stars in M90, with the spiral galaxy eventually fading as a result.

M90 is located 55 million light-years from Earth, but it’s one of the very few galaxies getting closer to us. Its orbit through the Virgo cluster has accelerated so much that M90 is in the process of escaping the cluster entirely. By happenstance, it’s moving in our direction. Astronomers have measured other galaxies in the Virgo cluster at similar speeds, but in the opposite direction. As M90 continues to move toward us over billions of years, it will also be evolving into a lenticular galaxy.

› 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...