By Amita Thapa Magar, Binod Dawadi, and Pankaj KC
The study was done taking the reference dates from 12th Feb to 16th Feb 2010. Based on these references, the prediction was made for 23rd Feb. Giovanni and NAAPS were used in order to make the prediction.
This figures derived (shown above) are self-explanatory. It clearly shows the prevalence of westerly wind in transporting the pollutants from western Indian provinces to Nepal and down to Bangladesh. Although the value of AOD is quite high (0.47) for 12 February, Nepal seems to be quite clear of any pollutants on that particular day. This might be because of recent rainfall in Kathmandu Valley. Again after 12th February, the average AOD for the region decreases, but the figure indicates that the AOD for Nepal is increasing. This also clearly indicates the prevalence of westerly wind in the region.
The major pollutant in this region seems to be dust particles. This conclusion is based on the prediction made by NAAPS (see figure below)
The above mentioned images clearly indicate that the major pollutant contributing to the increased AOD in the region is the dust particles. And because of the prevalence of the westerly wind, these dust particles (probably from Sahara desert and Rajasthan) is being transported to Nepal and down to Bangladesh. Hence, the prediction for 23rd February is quite dusty for Nepal with the concentration ranging from 20-24 micrograms/cubic meter.Posted by Amy Huff at February 15, 2010 11:49 PM