| Summary: | We use the Weather Research and Forecast model using the GOCART dust module (WRF-CHEM) to simulate the particulate matter variations in the Sahel during the winter seasons (January-March) of 1960-2014. Two simulations are undertaken where the direct aerosol feedback is turned off, and only transport is considered and where the direct aerosol feedback is turned on. We find that simulated Sahelian PM10 and PM2.5 concentrations were lower in the 1960s and after 2003, and higher during the period between 1988 and 2002. Higher Sahelian PM10 concentrations are due to stronger winds between the surface and 925 hPa over the Sahara, which transport dust into the Sahel. Negative PM10 concentration anomalies are found over the Bodele Depression and associated with weaker 925 wind anomalies after 1997 through 2014. Further west, positive PM10 concentration anomalies are found across the Adrar Plateau in the Sahara and responsible for dust transport to the Western Sahel. The North Atlantic Oscillation (NAO) is positively correlated to Sahelian dust concentrations especially during the periods of 1960-1970 and 1988-2002. The temporal/spatial patterns of PM10 concentrations have significant respiratory health implications for inhabitants of the Sahel. jfm6014nofeedTime averaged January-february-march monthly 1960-2014 WRF-CHEM data files.janmar6014feedmTime-averaged January-March netcdf file with variables from WRF-CHEM model. Aerosol direct radiation feedback included.sahara_pm10_naoPM10 anomalies for the Sahara and sub-regions around Bodele and Adrar mountains and the NAO index for 1960-2014 JFM.sahel_pm10_naoPM10 anomalies for the Sahel, West, Central and Eastern Sahel regions.
|
|---|