The effects of sand dust storms on greenhouse gases

In Asia, sand dust storms (SDSs) occur nearly every year, especially in northern China. However, there is little research about the relationship between SDSs and greenhouse gases (GHGs). In this article, we selected four SDSs that occurred in Asia in the spring of 2009 and 2010. We monitored the areas covered by these SDSs using Moderate Resolution Imaging Spectroradiometer (MODIS) data, then we used Greenhouse Gases Observing Satellite (GOSAT) data to check how the SDSs affected the concentrations of CO2 and CH4. We then compared the concentrations of CO2 and CH4 on SDS days with the monthly mean values of the months in which SDSs occurred. We also compared the concentrations of CO2 and CH4 on SDS days with the values before and after the SDSs. After analysis, we found that SDSs had increased the concentrations of CO2 and CH4 in the atmosphere. When the SDSs occurred, the concentrations of CO2 and CH4 increased and reached peak values on the last or penultimate days of the storms and then decreased to their normal values. Atmospheric flow is the main reason for the increase in concentration of CO2, and the lack of the free radical (OH) during SDSs and the presence of CH4 sources in southeast China are the main reasons for the increase in concentration of CH4. We also found that in arid and semi-arid areas, SDSs had little effect on the concentration of these two GHGs.