Dust storms that sweep northern India during the summer reach as far as the top of the Himalayas blanketing the snow cover and potentially contributing to climate change, Indian scientists have cautioned.
Images obtained by American Landsat satellites show layers of dust over the snow and glaciers in the high altitude Himalayan terrains, according to Ramesh Singh and Anup Prasad of the Indian Institute of Technology (IIT), Kanpur.
"Intense dust storms, depending upon the wind direction, influence the snow cover," the scientists said in a report released on Tuesday in a journal of the American Geophysical Union. "A deposition of dust over snow and glacier cover every year may influence the melting rate of snow and glaciers," they said.
While western and central Himalayas were affected, the eastern parts of the mountain range showed no influence of the dust storms, researchers said.
The scientists said that snow and glacier cover in the western Himalaya region are very important because four major rivers - the Indus, Ganges, Brahmaputra, and Yamuna - originate there. "Changes in snow and glacier cover influence the discharge and flow of these perennial rivers," they said.
Analysis of satellite data by the IIT scientists showed that the extent of snow cover has been decreasing faster during the 1990s as compared with the 1970s. Besides influencing the hydrological regime of the basin, this shrinking snow cover can affect the climatic conditions of the Indian subcontinent, they said.