Long-term variations of surface air temperature during summer in India

摘要

Increase in our earth's surface air temperature has been a subject of major concern in the recent years, as it may destroy the existing ecosystem and exert varied adverse effects on mankind and vegetation. In view of the gravity of the impending crises, the changes in surface air temperature during summer (March-June), their expected statistical critical limits and possible association with the changes in stratospheric ozone, aerosol concentration and solar irradiance have been investigated for different Indian regions over a period of 103 years from 1901 to 2003. It is observed that the overall air temperature is higher in the northwest (NW), north central (NC) and interior peninsula (IP) regions of India compared to the east coast (EC), west coast (WC), northeast (NE) and western Himalayan (WH) regions. However. the surface air temperature during summer is found to exhibit a small decreasing trend in the NW and WH regions and a small increasing trend in the IP, EC, NC, NE and WC regions. The results are discussed in light of observed decreasing trend in stratospheric column ozone (SCO), solar irradiance, concentration of aerosols and overall wind direction during summer. The maximum surface air temperatures for different Indian regions are observed to be well within the statistically computed critical limits.