We recently featured several important scientists who use Terra data in their research, including Dr. Rebecca Buchholz (check out the post here) who works with Dr. Helen Worden, the US Principal Investigator for the Measurements of Pollution in the Troposphere (MOPITT) sensor to evaluate spatial patterns of air pollution critical for natural hazard response and public health planning.
MOPITT data are used to derive carbon monoxide concentrations such as those released from burning vegetation, coal, and other combustible plant material. MOPITT carbon monoxide measurements are used to determine where wildfires are burning and to infer the presence of other air pollutants, too. After analyzing over 15 years of data, the MOPITT team found that overall carbon monoxide levels have decreased globally over the past decade, but with varying amounts related to regional land use differences. Additionally, the team also discovered that an increase in new seasonal peaks of air pollution– especially from summer wildfires burning in the American Pacific Northwest – contribute to increased health risks “downwind” of these fires – even impacting places as far away as Colorado! Find out more about this research in this NCAR/UCAR News article and this Earth Observatory Image of the Day!
With Terra’s 25th Anniversary only two years away (December 2024), we’re kicking off the celebration early in our News and Events section with a new series highlighting some of Terra’s researchers, data users, educators, and science communicators. We’re especially excited to promote current and proposed research that uses Terra data in unique or novel ways! (Do you know someone who’s made important contributions to the Terra mission? Or a groundbreaking Terra study that you feel made a substantial impact in the fields of earth science or remote sensing? We’d love to feature them – email us your ideas!)
Our first post in this series highlights three trailblazing women at NASA who have contributed to Terra’s scientific legacy, while showcasing the collaborative efforts among scientists at Goddard, JPL, and NCAR/UCAR. Check out their stories below!
Dr. Nai-Yung Christina Hsu (GSFC)
Dr. Christina Hsu, a researcher from GSFC, has incorporated data from many of Terra’s instruments into her research. Most notably, in 2004, she developed a Deep Blue algorithm for MODIS data that better characterizes aerosol properties over deserts and urban areas. (Read the groundbreaking article here!)
More recently, Dr. Hsu collaborated with a team studying regional differences in air pollution reductions, due to the global COVID-19 lockdowns of 2020. She used datasets from MODIS and MISR (two instruments on Terra) to analyze aerosol optical depth (click the link to learn more!). Learn more about Dr. Hsu’s research using this link, and access the full article here!
Abigail (Abbey) Nastan (JPL)
Check out this recent Earthdata feature of our own MISR instrument Applications and Communications lead, Abbey Nastan! This summary gives an overview of the diverse portfolio of projects that Abbey is currently working on, including MERLIN – a unique visualization tool that leverages the MISR Plume Height Project dataset, giving new life to “old-er” data.
Meet Dr. Rebecca Buchholz, a MOPITT Project Scientist who has worked at NCAR/UCAR since 2014 and has used MOPITT’s carbon monoxide dataset to study long-term patterns of air pollution transportation, especially that associated with wildfires. In a Scientific American news article last month, Dr. Buchholz summarized her recent research findings (published in Nature Communications) that show a significant increase in Western U.S. wildfire air pollution during the month of August, a new peak that largely negates California’s efforts to reduce annual air pollution. (She also gave Terra’s long data-record a shout-out!) Read more about her research here!
To return function to 16 printed wire assemblies, including the two most recent, Terra’s Flight Operations Team rebooted Terra’s solid state recorder, on September 22, 2021. The successful reboot of Terra’s solid state recorder returned Terra to a level that allows full science acquisitions from all five instruments (ASTER, CERES, MISR, MODIS, and MOPITT).
The recorder reboot took nearly 12 hours to complete. The board-by-board power up sequencing resulted in all 16 printed wire assemblies of the 16 offline assemblies returning to operational status. Terra now has all 58 assemblies in service, and Terra’s data storage capacity is at the same level it had at launch. There are currently no known hardware limitations to the operation of Terra or any of its sensors and there is currently no official passivation (mission end) date.
For over two decades Terra has collected valuable data about Earth’s systems. In February 2020 Terra stopped doing platform maneuvers that would control its equator crossing time in order to maintain fuel for collision avoidance maneuvers. The remaining fuel will also be used to lower Terra’s orbit as part of its eventual passivation process. Now with the printed wire assemblies being returned to full function, Terra will be able to collect full data acquisitions from all five instruments throughout this process.
Terra will also continue collecting data after an orbit lowering maneuver planned for Fall 2022. The maneuver upholds agreements to ensure Terra is a safe distance from the other missions in the 705-km Earth Observing Satellite Constellation when fuel to maintain Terra’s orbit has been depleted.
“The science community views the changes in crossing time and orbit altitude as continuation of normal data collection for those products not affected by the orbital changes as well as an opportunity to do novel science with those that are affected,” according to Kurtis Thome, Terra Project Scientist. The Terra Project fully expects the Terra platform and all five instruments to operate past 2026 allowing them to maintain their status as leaders in Earth science data production. Terra’s long-term data record will continue to contribute to the Earth Science Division’s key science questions:
How is the global Earth system changing?
What causes these changes in the Earth system?
How will the Earth system change in the future?
How can Earth system science provide societal benefit?
Terra, the flagship Earth Observing Satellite, continues to be a leader in Earth science data, contributing to scientific research and applications worldwide, now with data capacity levels restored by a successful solid state recorder reboot.
The Principal Investigator for the Measurements Of Pollution In the Troposphere (MOPITT) instrument on-board Terra, James R. Drummond, was awarded the Canadian Aeronautics and Space Insitut Alouette Award. The Alouette Award is awarded in recognition of outstanding contributions to the advancement of Canadian space technology, application, science, or engineering. Read the entire press release from CASI.
CASI Aloutte Award Press Release
Jim Drummond has been the Principal Investigator for a spectacularly successful Canadian satellite instrument for three decades, and also has made many invaluable contributions to Canada’s space program over the course of his long and distinguished career. These contributions, combined with his impassioned and tireless leadership in the satellite community, both nationally and internationally, have provided a body of research and accomplishments that make him an outstanding recipient of this prestigious award.
Jim is best-known in the space community for his leadership of the Canadian-led space instrument MOPITT (Measurement Of Pollution In The Troposphere) from conception to launch to celebrating its 20th anniversary on orbit. MOPITT was launched on NASA’s Terra satellite on December 18, 1999 and since then has made more than 1.3 billion measurements, resulting in over 470 publications. MOPITT measures carbon monoxide, and is notable for producing the first continuous global tropospheric chemical measurements from satellite and for mapping the global transport of pollution. MOPITT is a Canadian instrument; conceived, designed and constructed in Canada.
Jim began his scientific career at the University of Oxford where he completed his D.Phil. and a Post-Doctoral Fellowship, joining the Physics Department at the University of Toronto in 1979. Jim was the first person to thoroughly develop the concept of the length-modulated radiometer, recognizing the advantages that it offered over pressure-modulated radiometers. Jim and his students developed both balloon-borne and ground-based instruments based on these principles. In the late 1980s, he conceived the original concept for a nadir-viewing satellite instrument capable of measuring tropospheric constituents, including the acquisition of some vertical information using a combination of pressure-modulated cells to probe the upper troposphere and length-modulated cells for the lower troposphere.
Jim’s dedication culminated in the successful launch of the MOPITT instrument in 1999. Twenty years post-launch, Jim continues to be the Principal Investigator for MOPITT, leading an international team of Co-Investigators, including colleagues from the National Center for Atmospheric Research in Colorado, which is responsible for the retrievals.
MOPITT is the first satellite instrument to make long-term global measurements of tropospheric pollutants, focusing on carbon monoxide. It is an eight-channel scanning radiometer that measures upwelling thermal emission and reflected solar radiation from the Earth’s surface and atmosphere. As PI, Jim maintained an active participation in every aspect of the MOPITT instrument design, testing, and characterization, taking a hands-on approach. As one colleague remarked at an international meeting some years ago, after hearing Jim give a talk on the MOPITT instrument, “it’s impressive how well he knows every detail of that instrument inside-out”.
Jim and the Terra satellite team received the 2019 William T. Pecora Team Award from NASA and the U.S. Department of the Interior. The citation notes that “Terra is arguably one of the most successful Earth-sensing satellites ever deployed.” The citation also says that MOPITT was the first instrument “designed to observe the distribution and transport of tropospheric carbon monoxide and, along with other sensors, has helped advance our understanding of air quality and biomass burning emissions.”
Jim is a highly active contributor in the national and international scientific community including service on multiple high-level committees. Of particular relevance to space, he is currently a member of the federal government’s Space Advisory Board and a Member of CSA’s Atmospheric Science Advisory Committee. He was the founding President of the Canadian Network of Northern Research Operators (CNNRO), which was established to advance the collective interests of Canada’s northern research infrastructure operators. From 2014 to 2018, he was the Chair of the Forum of Arctic Research Operators (FARO), which has 20 member nations and aims to facilitate and optimise logistics and operational support for scientific research in the Arctic. Other international roles include Member of the Steering Committee for Network for the Detection of Atmospheric Composition Change, Member and Secretary of the International Commission on Atmospheric Chemistry and Global Pollution, and Canadian Representative to the International Association for Meteorology and Atmospheric Science.
MOPITT measurements continue to be widely used around the world, meeting a great desire for global tropospheric measurements. MOPITT produced the first long-term global maps of carbon monoxide, including movies that clearly show the transport of the products of pollution and biomass burning plumes around the world. Without Jim’s dedication, commitment, and outstanding grasp of experimental issues, MOPITT would not be the success that it is.
Difference of mean tropospheric OMI NO2 columns from 2005–2006 to 2008–2009, and from 2011–2012 to 2014–2015. The unit is 1015 mole/cm2. (G and H) same as A–F, but for MOPITT surface layer CO measurements with unit ppb (parts per billion).
A recent article published in PNAS points out that efforts to reduce nitrogen dioxide and carbon monoxide emissions between 2011 – 2015 have slowed in the United States, despite previous estimates that emissions were decreasing. These “bottom-up” estimates used ground-based measurements, inventories and models to predict these smog-producing emissions. However, when viewed from above, through satellite data from MOPITT and OMI, both nitrogen dioxide and carbon monoxide levels have not decreased.
Researchers concluded that emissions, especially for nitrogen dioxide, have not decreased as thought because of vehicle and industrial emissions. Industrial and construction equipment emissions are growing, while heavy duty truck diesel emissions may have been overlooked in ground-based measurements. Car emissions also continue to be a pollution source, but are now contributing a smaller proportion of total emissions.
One thing is certain, that viewing from above gives scientists the opportunity to see the whole United States, instead of relying on site specific ground based measurements.