Yuxuan Wang Receives NASA Grant to Study Drought Stress on Biogenic Emissions

Three-Year Grant Funded at $586K

Drought, a naturally recurring hazard, has adverse effects that can reach beyond causing water shortage and damaging agriculture.

Yuxuan Wang

According to Yuxuan Wang, assistant professor of atmospheric chemistry in the Department of Earth and Atmospheric Sciences at the University of Houston, “air quality typically gets worse during drought periods, which cause damages to public health, but the scientific community does not yet have the ability to accurately predict how drought would change sources and sinks of air pollutants.”

Wang recently received a three-year grant of $586,102 from NASA to study an important aspect of drought’s influence on air quality: vegetative emissions. Vegetation, particularly broadleaf trees, emits biogenic volatile organic compounds, or BVOCs, which are known precursors to ozone and particulate matter, two criteria air pollutants that are regulated worldwide.

While people have long known that BVOCs are important, Wang says the impact of drought on emissions from vegetation has only recently begun to be recognized, with new algorithms developed to attempt to account for that. The parameters in the algorithms, however, require measurement data collected over the life cycle of droughts for testing, verification, and refinement. Such field data is scarce even in rich countries like the United States.

Recognizing the problem, Wang and her colleagues decided to turn to remote-sensing data collected by satellites.

Satellite data have large spatial and temporal coverage and do not miss large-scale droughts. The challenge is to correctly interpret remote-sensing signals picked up by satellites and tease out the response of BVOCs emissions to droughts when they start, intensify, and dissipate.

With the NASA funding, Wang’s project will tackle this challenge through integrated use of state-of-the-art models that simulate atmospheric chemistry and transport, mathematical methods called inversion, and other datasets such as surface observations and aircraft data.

The outcome of the project will be an improved scientific understanding and better-constrained algorithms that quantify the response of vegetative BVOC emissions to droughts. Such algorithms will be useful to improve air quality forecasts during drought and to predict atmosphere-biosphere interactions under a warmer climate with droughts likely to become more frequent and intensive.

Other investigators involved with the project include Alex Guenther and Saewung Kim at the University of California, Irvine.