NASA-funded climate change study focus of meeting at Clark


Christopher Williams, Feng Gao, Yanmin Shuai, Crystal Schaaf, Jeff Masek Christopher Williams, assistant professor of geography; Feng Gao, physical scientist at the USDA Agricultural Research Service; Yanmin Shuai, Crystal Schaaf, professor at UMass Boston; and Jeff Masek, NASA research scientist.

Christopher Williams, assistant professor of geography, welcomed a group of distinguished colleagues to a Nov. 22 project meeting at Clark University, where they continued to develop methods for more accurately measuring climate change.

Williams and his fellow team members, whom he describes as “leaders in the field of remote sensing,” are in their third year of a study titled Albedo Trends Related to Land Cover Change and Disturbance: A Multi-sensor Approach,” funded by NASA’s Science of Terra and Aqua Program.

Surface albedo, the fraction of sunlight reflected off of earth’s surfaces, varies with land cover type. Changes in reflectance resulting from alterations in land cover (for example, from forest to cropland or savanna to grassland) can cause the earth’s temperature to rise or fall, contributing to climate change. By carefully measuring the albedo of different land cover types and combining that information with historical and projected future land cover over the globe, the team is improving estimates of regional and global climate variations.

Project findings displaying (a) the global distribution of historical land cover conversions, primarily to croplands (CRO) and (b) the associated changes in surface albedo. Project findings displaying (a) the global distribution of historical land cover conversions, primarily to croplands (CRO) and (b) the associated changes in surface albedo.

The scientists are charged with developing data products to determine the impact of land cover change on albedo trends. 

“Our findings should help reduce uncertainty about the magnitude of global climate change caused by land-cover conversions, and help inform how we might manage lands to mitigate climate change,” Williams said.

The research team is collecting reflectance data from remote-sensing technology aboard Landsat satellites and from MODIS (Moderate Resolution Imaging Spectroradiometer), a key instrument aboard the Terra (EOS AM) and Aqua (EOS PM) satellites. According to NASA, MODIS plays “a vital role in the development of validated, global, interactive Earth system models able to predict global change accurately enough to assist policy-makers in making sound decisions concerning the protection of our environment.”

The day concluded with an informal reception for the research team along with invited undergraduates, graduate students, and faculty.

The pioneering research of one of Clark’s early 20th century instructors in physics did not go unremarked.

Williams noted that the group “had fun connecting to Clark’s rocketry heritage through Robert Goddard, whose work laid an important foundation for the space-based earth observation that we explore today.”

Participating in the day’s events alongside Williams were Jeff Masek, research scientist in the Biospheric Sciences Laboratory of NASA’s Goddard Space Flight Center in Greenbelt, Md.; Feng Gao, physical scientist with the Hydrology and Remote Sensing Laboratory of the USDA Agricultural Research Service in Beltsville, Md., and Crystal Schaaf, professor in the Department of Environmental, Earth, and Ocean Sciences at the University of Massachusetts Boston.