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Langley Celebrates Asian American, Native Hawaiian and Pacific Islander Heritage Month Recognizing SAGE III / DEVELOP Team Member

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NASA commemorates Asian American, Native Hawaiian and Pacific Islander (AANHPI) Heritage Month each May to celebrate the achievements of employees of AANHPI descent.

Daniel Mangosing, a software release administrator and web developer at NASA’s Langley Research Center in Hampton, Virginia, proudly celebrates his family’s Filipino heritage.

While his parents were born and raised in a small Philippine town called San Felipe, Mangosing and his older sister were born in Agana, Guam, where his father was stationed while serving in the U.S. Navy. The family then lived all over the United States before finally landing in Newport News, Virginia, where his father retired from the Navy. Mangosing’s two younger brothers were born during his family’s travels in the States.

“Some of my happiest childhood memories were from our time in Charleston, South Carolina, Kingsville, Texas, and Newport News,” said Mangosing. 

Mangosing (right) with his son Matthew and their family dog Milo.
Credit: Daniel Mangosing

Mangosing graduated from Christopher Newport University in Newport News with a bachelor’s degree in computer science and graduated from Thomas Nelson Community College with an associate degree in graphic and media design. He’s currently working towards a bachelor’s degree in graphic design at Old Dominion University in Norfolk, Virginia.

After college, Mangosing started his career as a contractor at NASA Langley in 1990 working as a computer resource specialist and ground support equipment engineer.

Mangosing began working in web development by designing and connecting his first contract company’s website to the Internet. Nine years later, he changed roles and assisted in developing the website for the Stratospheric Aerosol and Gas Experiment (SAGE) III/Meteor mission and helped manage and develop Langley’s Atmospheric Sciences Division’s web server.

“I’ve worked on most of the websites in the Science Directorate at NASA Langley,” said Mangosing. These include sites for many of Langley’s most important science missions, along with various websites supporting airborne and validation campaigns.

After working on an airborne data website, Mangosing had the opportunity to return to the SAGE team and help develop the mission’s public website.

Currently, Mangosing splits his time with the SAGE III team as a web developer and the NASA DEVELOP program as a software release administrator, web developer and mentor for the communications/outreach and geoinformatics teams.

“My career path at NASA has been steady. I like to think that my motto is ‘to work on cool things and learn something new every day,’” said Mangosing.

Day-to-day, Mangosing enjoys collaborating with people of varying backgrounds and expertise to accomplish the mission at hand. Having teams of scientists, engineers, science writers, and web developers working together at NASA is essential not only to achieve the NASA mission, but help the public understand advancements in space exploration, scientific discovery and aeronautics research.

“Communicating complex concepts, whether by dissecting those ideas into easier-to-understand formats or visualizing those concepts in illustrations or videos, helps spread the NASA mission to the American public,” said Mangosing.

Throughout his time at NASA, Mangosing’s experiences exceeded his career dreams.

“After the LITE and MAPS missions, I remember thinking that only a tiny percentage of people in the world ever get to work inside the mission control center in Houston and meet the astronauts who would then go into space working in the Space Shuttle program. This is something I would have never had the opportunity to experience if I didn’t work for NASA,” said Mangosing.

Mangosing worked as a mission planner for the Space Shuttle missions, Measurement of Air Pollution from Satellites (MAPS) and Lidar In-Space Technology Experiment (LITE), in the 1990s.
Credit: Daniel Mangosing

Mangosing is proud to be an Asian-American and live in a country that recognizes his culture and the contributions his heritage brings to the vibrant diversity of America.

“Asian-Americans have contributed to many areas, from cuisine, design, science and technology, medicine and law,” said Mangosing. “Celebrating AANHPI month to me means that America acknowledges and recognizes the contributions Asian-Americans have made in the country, not just at places like NASA, but in all walks of life.”

NASA Langley opens first new lab in nearly 30 years

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Read more in the Daily Press about the Measurement Systems Lab, NASA Langley Research Center‘s new, state-of-the-art research facility for developing, testing and implementing new sensor and instrument technologies, including the SAGE IV prototype.
Read more here. 

More on SAGE IV: 

The Stratospheric Aerosol and Gas Experiment IV (SAGE IV) Pathfinder is the next generation in a line of instruments that have been monitoring stratospheric ozone, aerosols, and trace gases for over four decades. Over the years, these instruments have collected data on the decline of ozone in the Earth’s atmosphere and have hinted at a potential recovery in the ozone hole. The SAGE IV instrument will maintain the long-term data record of measurements monitoring the Earth’s atmosphere, but in an innovative and cost-efficient way.

Compared to the large SAGE III instrument making measurements from the International Space Station, the SAGE IV solar occultation imager will be the size of a large shoebox. The SAGE III/ISS instrument makes its occultation measurements by scanning the sun back and forth within a small field of view each time. With its simplified measurement technique and hardware, SAGE IV will have the capability to capture an image of the entire solar disk eliminating major technological and algorithmic challenges that were present in previous solar occultation instruments.

Photo Credit: David Bowman

SAGE III Observes ISS Contamination Environment

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Operating a science instrument aboard a crewed, frequently visited space station the size of a football field poses many challenges to data collection and quality. The Stratospheric Aerosol and Gas Experiment (SAGE) III instrument, currently on board the International Space Station (ISS), is equipped with the tools necessary to deal with these challenges.

Commanded from NASA’s Langley Research Center in Hampton, VA, SAGE III is a solar and lunar occultation instrument mounted externally on the ISS on ExPRESS Logistics Carrier-4 (ELC-4) measuring Earth’s stratospheric ozone, aerosols, water vapor, and other trace gases. Every time the sun, or moon, rises and sets, SAGE uses the light that passes through the atmosphere to measure gases and particles in that region of the atmosphere.

The ISS environment has proved to be an incredibly dynamic platform, with many factors affecting payload operations and Earth science data collection. Ideally, SAGE III would have a clean line of sight to make measurements with no mechanical disturbances or vehicles visiting the ISS. Because this is not always the case, the instrument payload was designed with several sensors that closely monitor local environmental conditions. SAGE III was the first on ISS to be built with two Contamination Monitoring Packages (CMPs) designated CMP1 and CMP2, to manage contamination events as they arise.

CMP1 and CMP2 each have multiple microbalance sensors containing quartz crystals that vibrate at frequencies dependent on how much molecular contamination is deposited onto the sensors. The image below illustrates where CMP1 and CMP2 are located on the SAGE III/ISS payload and the orientations of their respective contamination sensors. Each microbalance sensor can detect contaminant deposition to a precision of about 1.5 nanograms.

Credits: IEST / NASA

Two CMP modules are required for effective contamination monitoring because the layout of the SAGE III payload could obstruct the view of an individual CMP sensor at a single location. The image below illustrates the combined fields of view for both CMP modules’ sensors relative to the ISS. There is some overlap in the sensors’ visibility in case sensor failure occurs.

Credits: IEST / NASA

Data from the CMP modules have allowed the SAGE III mission operations team to develop flight rules for visiting vehicles and ISS attitude changes to proactively protect the payload and telescope optics from contamination by commanding the contamination door closed during these ISS activities. In addition to the commands sent before an event to protect the optics and payload, if real-time data from the CMP modules indicate an unacceptable accretion rate of contamination, the payload’s flight computer will automatically close the contamination door to protect the optics and allow quality science data collection to continue safely. The instrument scan head can then rotate and stow the telescope aperture in the cleanest available direction. Fortunately, unexpected contamination levels have never been high enough to cause the automatic closure of the contamination door.

Prior to the SAGE III launch, the contamination budget estimated that the ISS solar panel outgassing would be the largest source of contamination in the ELC-4 environment. After further studying the CMP data on-orbit, the SAGE III team has determined that the numerous visiting vehicles have actually been the largest measured source of contamination. The analyses and information below have been recently published as a paper in the Journal of IEST last December titled “Contamination Analyses of ISS Vehicle Visits.”

During SAGE III’s time in orbit, the following vehicles have visited the ISS: Russian Soyuz and Progress, SpaceX Cargo Dragon Commercial Resupply Services (CRS) and Crew Dragon, Japanese H-II Transfer Vehicle (HTV), and Northrup Grumman’s Cygnus capsule. Both CMPs have direct and partial views of many of the ISS docking ports as indicated in the table below.

Credits: IEST / NASA

When a visiting vehicle is docking, undocking, or outgassing contamination levels are high, the SAGE III mission operations team can perform a Thermogravimetric Analysis (TGA) characterization of the CMP sensors.

“TGAs are essentially science on the CMPs,” said SAGE III CMP Lead Tyler Dawson. “We want stuff to stick to the CMPs so we can monitor what’s on the overall payload itself. The CMPs getting dirty is kind of their point.”

During a TGA, the missions operations team slowly increases the temperature of the CMP crystals, typically kept at –10°C, to burn off contamination.

“If we find during a TGA that contamination burns off at a specific temperature, we can determine what type of contamination we are burning off by matching to something that is already ‘known’ to burn off at that particular temperature,” said Dawson.

After over four years of collecting and studying the CMPs’ data, the SAGE III team found that Cargo Dragon vehicles consistently had the highest rates of chemisorbed deposition on the CMP sensors. When contamination is chemisorbed onto the sensor, it cannot be burned off and removed. Without chemisorption, contaminants would spontaneously desorb from the sensors over time as is seen for most other sources of SAGE III contamination.

The figure below shows how the total amount of contamination on the CMP1 Node 2 sensors has slowly increased since the beginning of the SAGE III mission in 2017 and has not since returned to its original beat frequency levels. These results strongly suggest that contamination has continued to chemisorb onto the CMP sensors and has not burned off during TGAs.

Credits: NASA

The figure also illustrates the relationship between the ISS’s solar beta angle, vehicle visits, and contamination levels. (Intermittent noise on the Node 2 Focused sensor is a known problem but has low impact on data analyses.)

During a high negative solar beta angle, there is less shading on the areas of the space station near the SAGE III payload, and the heating can cause increased vehicle outgassing towards ELC-4.

“This is information we did not know going into the SAGE III/ISS mission,” said Dawson.

Throughout the mission, when Cargo Dragon vehicles have visited the space station during a high negative solar beta angle, the SAGE III CMP Node 2 beat frequency increased without returning to previous contamination levels.

The CMP2 PMM sensor also experienced similar results. Despite multiple TGAs performed, a new increased beat frequency baseline persisted correlating with Cargo Dragon visits.

“The CMP data really help characterize what is being brought to the ISS, which is typically a closed environment, except for what these vehicles are bringing from Earth,” said Dawson.

Without continuous contamination monitoring by the CMPs and exercising of the contamination door, it is likely the SAGE III atmospheric science data products would have been degraded. Future external ISS payloads should consider the dynamic environment of the space station to be able to protect and monitor sensitive science instruments for potential contamination.

Not only do the CMPs protect the payload and improve the science data products, but the CMP data also validate what external partners expect to see as ISS contamination sources. The SAGE III team provides the ISS Program and other relevant parties with contamination data correlated with station events which aid in closing the knowledge gap of on-orbit sources of contamination.

For more information about the SAGE III/ISS Contamination Monitoring Package data and studies, the paper SAGE III/ISS Contamination Monitoring Package: Observations in Orbit can be accessed online on the NASA Technical Reports Server.

SAGE III Instrument Detects Stratospheric Effects of Indonesian Volcanic Eruption

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Dec. 4, 2021, Mount Semeru, one of the largest and most active volcanoes on the Indonesian island of Java, erupted. Ash, avalanches, and rivers of water and volcanic debris called lahars resulted in the tragic deaths of more than 50 people.

At the time of the eruption, the Stratospheric Aerosol and Gas Experiment (SAGE) III instrument on the International Space Station (ISS) was observing other areas of the planet. One month later, SAGE III took measurements within the latitude band of Mount Semeru (8°S) and detected an enhancement of aerosols in Earth’s stratosphere at an altitude of approximately 19 km. Because of the orbital path of the ISS, SAGE III observations usually pass through a given geographical area of Earth’s atmosphere once per month.

These observations are important because they help NASA scientists understand global climate change better. Stratospheric aerosols from eruptions such as Mount Semeru can actively cool the Earth’s surface by reflecting sunlight back to space. In terms of climate impact, Semeru’s effect is small, similar to the eruption of Fukutoku-Okanoba in the Philippine Sea in August 2021. It is important to note, though, that multiple eruptions of this same degree have a cumulative effect in Earth’s atmosphere.

The map below illustrates the geographic area of the January 2022 SAGE III measurements.

Credits: NASA/Kevin Leavor

The data plot below displays the spike in stratospheric aerosols from the eruption above the tropopause, the area in Earth’s atmosphere directly below the stratosphere. The data from SAGE III did not show much ash within the aerosol cloud.

Credits: NASA/Kevin Leavor

Below, you can see the change in aerosol particle size due to the sulfur dioxide injected into the atmosphere. The sulfur dioxide from the eruption reacts with water in Earth’s atmosphere to form sulfuric acid, which then condenses into new sulfate droplets which are detected by the SAGE III instrument.

Credits: NASA/Kevin Leavor

After further analysis of additional SAGE III January 2022 data, NASA scientists have seen the aerosol cloud from the eruption remain in the Southern Hemisphere tropics, but not spread much in longitude as it is driven around the globe by stratospheric wind patterns.

As SAGE III visits the tropics over the following months, the SAGE team will be watching to see how the Semeru aerosol cloud mixes with the rest of the stratosphere.


SAGE III/ISS Team Announces the Second Official Release of V5.2 Science Data Products

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The SAGE III/ISS Team is proud to announce the second official release of SAGE III/ISS products (V5.2) that are suitable for use in both validation and research studies for the data products as described in the Data Product User’s Guide (DPUG). The nominal monthly release of new SAGE III/ISS events will be processed only with V5.2 algorithm starting with March 2021. Version 5.1 remains publicly available for events from June 2017 through February 2021. This statement applies to SAGE III/ISS Version 5.2 Solar Level 1B, Solar Level 2, and Lunar Level 2 data products. The SAGE III/ISS Team recommends using Version 5.2 instead of Version 5.1 because of the modifications and improvements mentioned below.

Vertical profiles of ozone, nitrogen dioxide (NO2), and water vapor (H2O) concentrations, as well as multi-wavelength aerosol extinction coefficient, are included in the solar Level 2 data product files. Three ozone profiles are available in this release of the solar products: a UV based mesospheric product (i.e., “Ozone_Mes” in the product files) and two Chappuis-based products. One Chappuis-based product uses a spectrally-focused fitting retrieval (i.e., “Ozone_MLR”) while the other uses a broad-spectrum retrieval scheme that is similar to that of SAGE II (i.e., “Ozone_AO3”). Composite ozone and retrieved temperature/pressure products are not included in the V5.2 data set. Vertical profiles of ozone, nitrogen dioxide (NO2), and nitrogen trioxide (NO3) concentrations are included in the lunar Level 2 product files. Chlorine Dioxide (OClO) from lunar occultation is not included in this release. The channel wavelengths used in solar and lunar retrievals are available in the Data Product User’s Guide (DPUG).

Version 5.2 improvements and bug fixes recovered 311 more solar events (increase of 1.0%) compared to v5.1; 104 more lunar events (increase of 4.3%) compared to v5.1; improvements and the number of water vapor profiles withheld by QA was reduced from 570 (v5.1) to 30 (v5.2).

Reader Software:

Both IDL and Python reader software are available to access the products in the native format and a Python reader is available for the HDF format. The product formats have changed slightly, so the new readers are required for this release. Readers for previous versions of SAGE III data are not compatible with this version. However, the new IDL and Python data readers are backwards compatible with the previous version of the data product, in both formats.

Data Access Methods:

Direct Data Download

Earthdata Search

For questions regarding data usage, please ask us on the Earthdata Forum

Related URLS:

Enhanced Stratospheric Aerosols from Fukutoku-Okanoba Eruption

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Did you know active volcanoes lie beneath the ocean’s surface? The Stratospheric Aerosol and Gas Experiment (SAGE) III on the International Space Station (ISS) instrument spotted remnants of the Fukutoku-Okanoba undersea volcanic eruption in Earth’s stratosphere.

Fukutoku-Okanoba erupted vigorously in the Philippine Sea on Aug. 13, 2021. Although the volcano’s summit is approximately 80 feet under water, the powerful eruption was still forceful enough to send ash and sulfate aerosol particles high above the sea’s surface and well up into the lower stratosphere at an altitude of approximately 16 km. While SAGE III was not measuring in the immediate vicinity to capture data at the time of the eruption, SAGE III observations passed through the same latitude one week later, and measurements discerned a new aerosol layer in the lower stratosphere.

These are important observations for SAGE III to make, because they help scientists understand global climate change better. Stratospheric aerosols such as these act to cool the Earth’s surface by reflecting sunlight back to space.

It is worth noting that sulfate aerosols don’t blast straight from the mouth of an underwater volcano into the stratosphere. Sulfuric dioxide from the volcano reacts with water to form sulfuric acid, which then condenses into the sulfate droplets spotted by SAGE III.

The map below illustrates the geographic area of the late August 2021 SAGE III measurements.

The data plot below shows the clear spike in aerosols right above the tropopause (dotted line) from the eruption of Fukutoku-Okanoba. Although this was a comparably small eruption in relation to some in the historical record, multiple minor and moderate eruptions causing aerosol enhancements in the stratosphere have a cumulative effect. The result has been shown to be important when studying past changes in Earth’s climate, as well as predicting future changes.

Higher in the stratosphere around 23 km, SAGE III also saw an enhanced layer of aerosols remaining from the eruption of the La Soufrière volcano in April 2021.

The SAGE III team continues to examine the evolution of these volcanic disturbances in the stratosphere as the instrument samples the tropics/sub-tropics in the coming months.

Summer Interns Successfully Accomplish Science and Engineering Projects for SAGE III Mission

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While the COVID 19 pandemic caused another summer of virtual internships, it didn’t stop students from across the country from furthering their education and professional experience with NASA.

With over 1,000 applicants to the mission’s internship program, the Stratospheric Aerosol and Gas Experiment (SAGE) III team at Langley Research Center in Hampton, VA selected a team of six student interns to work on a variety of science and engineering projects during the 10-week summer session.

Maggie Zheng, a rising senior at the Massachusetts Institute of Technology (MIT) studying aerospace engineering, worked with the SAGE III science validation team on the code base and documentation for a new automated Quick Look tool of SAGE III’s atmospheric ozone and water vapor measurements. Typically, there is a period of two months between SAGE III collecting data and when that data is released to the public. Zheng’s development of a Quick Look tool will allow the SAGE III team to examine data before this post-processing period.

“The Quick Look tool will give scientists insights from our data on current events and will allow SAGE III data to contribute to ongoing conversations in the scientific community,” said Zheng.

Zheng will be further working with the SAGE III team on this project during the fall session of NASA internships.

SAGE III intern Thomas Nicewicz attended NASA’s Boeing Orbital Flight Test-2 Launch in August 2021 and toured some of Kennedy Space Center’s facilities such as the Vehicle Assembly Building (VAB).

Thomas Nicewicz, a student at Washington and Jefferson College, worked to improve the coordinate transformation from the Disturbance Monitoring Package (DMP) to the Sensor Assembly (SA) on the SAGE III instrument. The coordinate transformation is needed to map small changes in attitude seen by the DMP to the SA and improves the team’s knowledge of SAGE III’s pointing.

In honor of National Interns Day, Nicewicz was randomly selected by the NASA internship program to attend the Boeing Orbital Flight Test-2 launch at NASA’s Kennedy Space Center in Florida with interns from across the agency. This uncrewed mission tested the end-to-end capabilities of the Starliner spacecraft and Atlas V rocket from launch to docking to a return to Earth in the desert of the western United States. Interns were able to view the launch to the International Space Station (ISS) from the coast of Cape Canaveral and tour some of the center’s iconic facilities.

Anya Lomsadze, a junior at Yale University studying Statistics and Data Science and Energy Studies, completed a project to study the low aerosol extinction values in the SAGE III data set. Lomsadze created a software tool that automates identifying and modeling low aerosol values in the data set and identifies how reliable SAGE’s measurements are at these low values. Her analysis points to a possible detection limit of the SAGE III instrument for measuring low aerosol values in the lower altitudes of the stratosphere.

“Through working on this project, collaborating with the other SAGE interns, and attending SAGE mission meetings, I learned about everything from atmospheric chemistry to collaborative code development to how ISS dockings can impact data collection. I’ve learned invaluable lessons this summer at Langley about the scientific process, collaboration, and lifelong learning that I am excited to apply in school, work, and life,” said Lomsadze.

Did you know that high school students can apply to the NASA internship program? Sophia Steven, a rising high school senior at Peak to Peak Charter School in Lafayette, Colorado joined the SAGE III internship team this summer. She created a user-friendly interface for extracting SAGE III science data from the database on the SAGE-PRIME data processing server. Based on a user’s requests, the interface can query the SAGE III database and return a collection containing the user’s specific data request, as well as a plot of the returned data all using Python.

Liam Hunsberger, a rising senior at Purdue University studying Applied Physics and Planetary Science, worked on a solution to better process limb scattering events measured by the SAGE III instrument. To process a limb scattering event, the raw data is retrieved, relevant telemetry is extracted, and a dataset is built for each limb event from the spectral data. Through the existing software, this process is done manually. Hunsberger worked to automate the process in Python by completing a script that can batch process multiple science events, and also created a functionality to continually search for and process events.

Michael Villordon, a senior at the University of Texas at Dallas majoring in computer science, worked on the Aerosol Classification Machine Learning project. The goal of Villordon’s project was to create a process that could automatically identify if any given point in a SAGE III data profile contained clouds via machine learning. Clouds often interfere with SAGE III measurements and are physically and chemically distinct from other atmospheric aerosols. An automated process to filter or to identify clouds can ultimately improve the quality of the data set and analyses using those data. Villordon’s work advanced the machine learning algorithm to make this process faster, more efficient, and highly extensible within a Python framework.

Although the SAGE III team of interns did not physically gather in person this summer, they still found the virtual internship experience to be rewarding.

“I was able to meet often with my mentors and collaborate with the other SAGE III interns virtually through Microsoft Teams and Git. I really appreciated how much time the mentors spent in training us in skills that will be useful to us later in our careers as well. And of course, I also loved getting to know the mentors and interns a bit outside of trainings and work,” said Zheng.

The NASA internship program wouldn’t be successful without the team of mentors across the agency that dedicate their time to support, educate, and train interns each year.

“The comprehensive training modules developed by the SAGE III/ISS mentors equip interns with skills and knowledge to put into practice wherever their careers take them, maybe even as future NASA employees. These are skills interns often do not have exposure to in their college careers, but are very beneficial in both the academic and professional environments,” said Dr. Charles Hill, lead SAGE III/ISS mentor.

The LaRC team of mentors hosted a couple of “Fireside Chats” to socialize with the SAGE interns, and even held a virtual Bob Ross painting night.

SAGE III interns and mentors display their finished art after enjoying a virtual Bob Ross painting lesson.

The innovation, hard work, and dedication of the SAGE III summer internship team will continue to support and benefit the Langley mission team for the foreseeable future.

To apply for the next session of NASA internships, please visit

Studying Earth’s Stratospheric Water Vapor

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What does water vapor have in common with Sisyphus, the mythological Greek character cursed to roll a rock uphill only to have it roll back down again? Water is continuously cycling on Earth between bodies of water such as oceans, lakes and rivers, land surfaces, and in the atmosphere. When water warms and evaporates from the Earth’s surface it becomes gaseous in the form of water vapor, H2O. As water vapor rises into the atmosphere, it cools and can condense into clouds which can produce rain or snow bringing water back to the Earth’s surface. And the cycle begins again.

Water vapor is also an important component in Earth’s evolving climate system. As a major greenhouse gas – a gas that traps heat – water vapor absorbs heat produced by Earth’s surface and the shining Sun. The water molecules then emit that heat back to Earth’s surface which can increase the temperature. This relationship between an increase in water vapor in the atmosphere contributing to warming temperatures, and warmer temperatures causing an increase in water vapor is called a positive feedback loop.

Although water vapor in the stratosphere is only a few molecules per million air molecules, this positive feedback relationship between water vapor and temperature is important as scientists study to better understand how much this impacts Earth’s changing climate.

In addition to measuring stratospheric ozone and aerosols, the Stratospheric Aerosol and Gas Experiment (SAGE) III instrument on the International Space Station (ISS) measures trace gases including water vapor. Unlike many other science data instruments, SAGE III provides a very precise and highly accurate measurement of water vapor in the upper troposphere and throughout the stratosphere.

Other satellite-based instruments, such as the Microwave Limb Sounder (MLS) on NASA’s Aura and the High-Altitude Lidar Observatory (HALO), measure atmospheric water vapor in the upper troposphere and stratosphere. SAGE III uses the solar occultation technique, which is unique, in that it can take more precise measurements covering vertical layers of atmosphere.

“Because SAGE III provides such a high accuracy data set, we can look at different levels of the atmosphere in more detail than ever before. We can see every kilometer in the vertical profiles of data,” said Mijeong Park, Project Scientist at the National Center for Atmospheric Research in Boulder, CO.

In partnership with the National Center for Atmospheric Research (NCAR), the National Oceanic and Atmospheric Administration (NOAA), and the Jet Propulsion Laboratory (JPL), the SAGE III team at NASA’s Langley Research Center in Hampton, Virginia released initial analyses of the SAGE III water vapor data version 5.1 in the paper “Near-Global Variability of Stratospheric Water Vapor Observed by SAGE III/ISS.”

Throughout the paper, the SAGE III version 5.1 water vapor data are validated against MLS version 5 retrievals and show overall first-rate agreement between the two data sets. The relatively young SAGE III/ISS dataset is recording water vapor seasonal variability that agrees well with MLS from the tropopause through the middle stratosphere (∼16–30 km).

By looking at SAGE III data between 2017 and 2020, scientists were given some insight into the year-to-year variability of H2O during boreal summer monsoon season. A monsoon is a seasonal change in wind and rain patterns observed in certain parts of the world, including North America.

“By looking at multiple years of data, we can understand how much water vapor is going into the stratosphere through the summer monsoon circulation each year,” said Park.

In the figure above, SAGE III (a and c) is compared to MLS (b and d) for August 2017 (top) and January 2018 (bottom). In August of 2017, SAGE III H2O showed that water vapor over the North American monsoon region was relatively higher than over the Asian monsoon region. While the SAGE III instrument takes about one month to cover the latitude range ∼60N–60S, scientists have found that this monthly sampling captures more localized values of water vapor in the lower stratosphere.

Although the summer monsoon season varies year by year, SAGE’s ability to detect the interannual variability of stratospheric water vapor during monsoon season helps scientists better understand how changes in water vapor are contributing to Earth’s climate.

Scientists are also able to study relative humidity (RH) with SAGE III’s water vapor data. Relative humidity tells us how much water vapor is in the air, relative to how much water vapor the air could hold at a given temperature. As air temperatures rise, warmer air can hold more water vapor increasing the saturation point. Cold air can hold less water vapor.

The RH-temperature relationships captured by SAGE III agree with the near-tropopause data derived from high-resolution Upper Troposphere/Lower Stratosphere (UTLS) aircraft measurements, which enhances the science community’s confidence in the quality of the SAGE III data set.

“The SAGE III data can be used for more detailed studies of relative humidity distribution and its variability because of the accuracy. It will also help scientists to better simulate our climate using global climate models,” said Park.

While SAGE III will continue to measure water vapor from ISS over the coming years, a longer record of water vapor data is needed.

“It is very important to have a continuous measurement of water vapor anywhere on Earth. There are many ways to measure water vapor, by satellite, like SAGE, by airplane, or by ground-based instruments. There is only one continuous water vapor record of 30-plus years from balloon measurements in Boulder, Colorado. Satellite missions have limited lifetimes. We need continuous measurements of water vapor to really understand how water vapor affects our climate,” said Park.

Using SAGE III water vapor data collected from June 2017 – February 2021, the visualization illustrates the transport of water vapor in Earth’s stratosphere at various altitudes and latitudes. In the equatorial region, notable masses of dry air (blue/green colors) are seen rising upward from the tropopause, the transition point between the troposphere and stratosphere denoted by the grey dashed line, through the lower to mid-stratosphere. The orbit of the International Space Station enables SAGE III to observe the southern mid-latitudes, tropics and northern mid-latitudes every month, with the exception of July and December when data is confined to the mid-latitudes.
Credits: Mijeong Park/National Center for Atmospheric Research

New SAGE III Science Team Members Selected

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NASA’s Science Mission Directorate has selected proposals for the solicited SAGE III on ISS Science Team program. The individuals selected for this team, from a variety of diverse institutions, will conduct studies using the data from the SAGE III instrument to help better understand the composition of Earth’s atmosphere and how it’s evolving. These ten individuals, selected by competitive solicitation, will provide data analysis and independent validation, limb scatter retrieval algorithm development and adaptation, assessments of atmospheric composition, studies of clouds and aerosols, contributions to modeling efforts, and multi-sensor data product development. You can find descriptions of each member’s proposed work here.

SAGE III/ISS Science Team Members:

Peter Bernath/Old Dominion University
Mian Chin/Goddard Space Flight Center
Sean Davis/Office of Oceanic and Atmospheric Research, Boulder
Glenn Jaross/Goddard Space Flight Center
Lars Kalnajs/University of Colorado, Boulder
Travis Knepp/Langley Research Center
Katherine Emma Knowland/Universities Space Research Association, Columbia
Stanley Sander/Jet Propulsion Laboratory
Jean-Paul Vernier/National Institute of Aerospace Associates
Hsiang-Jui (Ray) Wang/Georgia Institute of Technology
Jun Wang/University of Iowa, Iowa City

SAGE III Carries on Critical Measurements of Stratospheric Aerosols and Ozone

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On the fourth anniversary of its first-light measurements, we are taking a look at some of the critical data collected by NASA’s Stratospheric Aerosol and Gas Experiment III (SAGE III) aboard the International Space Station. Launched to the station in February 2017, SAGE III is the most recent in a series of SAGE instruments that have measured stratospheric gases and aerosols from space. The SAGE family of instruments started in 1979 and is one of NASA’s longest-running Earth-observing programs.

Data from SAGE II helped confirm human-driven changes to the ozone layer, which contributed to the 1987 Montreal Protocol that banned some of the most destructive industrially-produced ozone-depleting chemicals. Stratospheric ozone acts as a sunscreen for the Earth, filtering out harmful solar radiation by absorbing some of the Sun’s ultraviolet rays, providing people, animals and plants some protection from that harmful radiation.

This latest SAGE III instrument is helping scientists monitor the recovery of ozone resulting from the reduction in emissions of ozone-depleting substances called for under the Montreal Protocol. SAGE III has also measured the intrusion of aerosols into the stratosphere from intense wildfires in Australia and California, and from volcanic eruptions. Those aerosols, which can remain in the stratosphere for months or even years, can lead to variability in the climate record. Water vapor, a potent greenhouse gas that can be lofted into the stratosphere by extreme storms, is also visible to SAGE III. Though it’s normal to have some water vapor in the stratosphere, using SAGE data, scientists can better understand how year-to-year changes in tropical weather affect the amount of water vapor in regions of the stratosphere influenced by the tropical weather circulation.

SAGE III makes measurements using solar and lunar occultation, a technique that involves looking at light from the Sun or Moon as it passes through Earth’s atmosphere at the edge, or limb, of the planet. The SAGE III payload on the space station is managed by NASA’s Langley Research Center in Hampton, Virginia and was developed in partnership with the European Space Agency, Ball Aerospace Technology Corporation, and NASA’s Johnson Space Center in Houston.

Allison McMahon (SSAI): Producer
Haley Reed (ADNET): Producer
David Flittner (NASA/LaRC): Scientist
Marilee Roell (NASA/LaRC): Scientist
Jamie Nehrir (NASA/LaRC): Engineer
Kevin Leavor (SSAI): Scientist
NASA’s Goddard Space Flight Center Conceptual Image Lab
NASA’s Scientific Visualization Studio

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Space Station Live: Wise Eye in the Sky


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NASA X Episode I: SAGE III Monitoring Earth


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SAGE III Integration and Test Timelapse


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Space Station Live: Studying Earth’s Sunscreen


SAGE III Sun Look Test Video

SAGE III Sunlook Test





NASA Real World: Ozone

NASA Real World: Good Ozone, Bad Ozone


NASA's Our World: Sunsets

NASA’s Our World: Sunsets and Atmosphere


SAGE III/ISS Overview Video

SAGE III/ISS Overview Video

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Mission Brochure





The SAGE Legacy's Next Chapter: SAGE III on the International Space Station

SAGE Earth Observer Article


SAGE III International Collaboration

SAGE III/ISS International Collaboration

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