Task 230

Joint Aerosol-Monsoon Experiment

Principal Investigator(s):

C. Li

Sponsor(s):

S-C. Tsay

Last Updated:

May 14, 2013 16:46:20

Description of Problem

Atmospheric aerosols, through interaction with clouds and alteration of the radiation, may influence the Asian Monsoon system, a critical component in the water cycle for this most populated continent of the world. Climate modeling studies of the aerosol-cloud-water cycle require detailed information about aerosol distribution and properties, which are highly variable and necessitate intense field deployments.

Scientific Objectives and Approach

Following the JAMEX/TIGERZ/RAJO-MEGHA field experiment conducted in Nepal and northern India during the pre-monsoon season (April to June) of 2009, we have analyzed data collected with sun photometers, radiometers, weather transmitters, and lidar. Using the data set, we looked into the properties and spatiotemporal distribution of aerosols in the region, and estimated their direct radiative effects.

Another field experiment, 7-SEAS/Dongsha, was conducted in South China Sea in spring 2010, as a pilot study of 7-SEAS (Seven SouthEast Asian Studies). A comprehensive suite of in situ instruments and lidar were deployed to measure the continental pollution outflow from the mainland of China, as well as the biomass burning smoke from Southeast Asia. Data analysis is currently underway. We are also planning for another major field campaign to be conducted in Southeast Asia in 2012, under the auspices of NASA SEAC4RS mission.

In addition to field experiments, we are also exploring the applications of NASA EOS satellite data in understanding the sources, properties, and impacts of aerosols and precursor gases. We have experimented methods to combine field measurements, satellite retrievals, and atmospheric modeling to study regional aerosol transport events.

Accomplishments

We have analyzed data from the JAMEX/ TIGERZ/RAJO-MEGHA field experiment. The results indicate the accumulation of aerosols along the southern slopes of the Himalayan mountain range. Radiative transfer modeling suggests very strong influences of aerosols on the surface radiation flux. A paper presently under preparation will report the findings to the scientific community (coauthor).

During the 7-SEAS/Dongsha experiment, a strong dust storm originating from NW China was captured for the first time in South China Sea. A paper describing this rare event and its potential impact has been submitted (coauthor).

We have analyzed some data from the field deployment in NW China in spring 2008. In a paper published in 2010 (Li et al., 2010a), we reported that dust leaving the Gobi deserts could have already been mixed with anthropogenic pollutants, and further interaction between them during long-range transport may alter the large-scale effects of Asian dust.

In collaboration with scientists in China and Argonne National Laboratory, we employed satellite data to investigate the efficacy of emission abatement measures in some Chinese Power Plants (Li et al., 2010b). This study demonstrates the potential of satellites in air pollution monitoring and management, and was highlighted by the American Geophysical Union as a research spotlight.

Refereed Journal Publications

Li, C., S.-C. Tsay, J. S. Fu, R. R. Dickerson, Q. Ji, S. W. Bell, Y. Gao, W. Zhang, J. Huang, Z. Li, and H. Chen (2010a), Anthropogenic air pollution observed near dust source regions in northwestern China during springtime 2008, J. Geophys. Res., 115, D00K22, doi:10.1029/2009JD013659.

Li, C., Q. Zhang, N. A. Krotkov, D. G. Streets, K. He, S.-C. Tsay, and J. F. Gleason (2010b), Recent large reduction in sulfur dioxide emissions from Chinese power plants observed by the Ozone Monitoring Instrument, Geophys. Res. Lett., 37, L08807, doi:10.1029/2010GL042594.

Li, C., T. Wen, Z. Li, R. R. Dickerson, Y. Yang, Y. Zhao, Y. Wang, and S.-C. Tsay (2010c), Concentrations and origins of atmospheric lead and other trace species at a rural site in northern China, J. Geophys. Res., 115, D00K23, doi:10.1029/2009JD013639.

Other Publications and Conferences

Awards:
Laboratory for Atmospheres, NASA/GSFC: Outstanding Performance Award – Science, December 8, 2010.