Response of Regional Air Quality to Severe Drought

EPA Grant Number: R835191
Title: Response of Regional Air Quality to Severe Drought
Investigators: Allen, David T. , McDonald-Buller, Elena
Current Investigators: Allen, David T. , Huang, Ling , Kimura, Yosuke , McDonald-Buller, Elena , McGaughey, Gary , Zheng, Jeff
Institution: The University of Texas at Austin
EPA Project Officer: Chung, Serena
Project Period: June 1, 2012 through May 31, 2015 (Extended to May 31, 2016)
Project Amount: $750,000
RFA: Extreme Event Impacts on Air Quality and Water Quality with a Changing Global Climate (2011) RFA Text |  Recipients Lists
Research Category: Air Quality and Air Toxics , Global Climate Change , Water and Watersheds , Climate Change , Air , Water


Severe droughts are a recurring phenomenon throughout the southwestern United States, and most climate models suggest that these droughts will become more severe as climate changes in response to increased concentrations of greenhouse gases and other radiative forcing species in the atmosphere. Results from the US Global Change Research Program suggest that Texas will see substantially decreased rainfall during summer and fall under future climate scenarios, making the State an appropriate test bed for examining how air quality will respond to drought.


Three categories of drought-induced changes in natural systems will be examined:

  1. Changes in biogenic emissions caused by changes in land cover and changes in water availability due to drought
  2. Changes in dry deposition caused by changes in land cover and changes in stomatal resistances due to drought
  3. Changes in atmospheric mixing heights and atmospheric water content caused by changes in soil moisture due to drought

Drought induced changes in agricultural operations will also be examined

  1. Changes in ammonia emissions, dry deposition, and biogenic emissions caused by changes in agricultural operations due to drought

Each of these four categories of drought induced changes will be examined individually, and in combination. While these are not the only changes that might influence air quality in response to drought, they are potentially some of the most important, and understanding the direction magnitude, and synergies between these effects will help advance our understanding of how air quality will respond to severe drought.


The approach will be to (i) develop air quality modeling tools that can be used to assess the impacts of regional droughts on ozone and speciated particulate matter concentrations, (ii) evaluate the modeling tools using comparisons between ensemble model predictions and observations in drought and non-drought years in Texas, and (iii) to make the modeling tools available to air quality managers by incorporating them into a widely used regulatory model.

Expected Results:

The proposed work will develop tools for incorporating drought stress into regional air quality models, test the models using historical data, and provide air quality managers access to these tools by incorporating them into a commonly used regulatory model.

Publications and Presentations:

Publications have been submitted on this project: View all 11 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 4 journal articles for this project

Progress and Final Reports:

  • 2012 Progress Report
  • 2013 Progress Report
  • 2014 Progress Report
  • Final Report