Department of Energy • Office of Science • Biological and Environmental Research1 CESD Overview

Objective● Study the impacts of dust on the North

American summer monsoon system

Approach● WRF-Chem is used to conduct numerical

experiments over 15 years using the MADE/SORGAM aerosol scheme coupled with the GOCART dust emission scheme

● Simulations performed for April-September 1995-2009 at 36 km horizontal resolution with and without dust

Impact● Simulated dust concentration and AOD

compared well with observations● Dust from the U.S. Southwest deserts

induces surface cooling of 1 W m-2 and atmospheric heating of 0.4 W m-2

● Dust heating of 0.3 K day-1 in the lower atmosphere strengthens the low-level meridional winds, leading to a 10-40% increase in the NAM precipitation

Desert Dust Impact on the Summer Monsoon System over Southwestern North America

Zhao C, X Liu, and LR Leung. 2012. “Impact of the Desert Dust on the Summer Monsoon System Over Southwestern North America,” Atmospheric Chemistry and Physics, 12, 3717-3731, DOI:10.5194/acp-12-3717-2012.

Dust induced diabatic heating over the desert (contours) and precipitation changes over Texas and New Mexico.

Dust induced change of zonal and meridional moisture fluxes in the monsoon system.