Long-term temperature analysis and its future projection during post-monsoon and winter season in the alluvial, red laterite and costal region of West Bengal

Nine IMD stations (Alipore, Krishnagar, Sagar Island, Midnapore, Berhampore, Bankura, Contai, Shantiniketan, Haldia), distributed randomly in alluvial, red-laterite and coastal regions of West Bengal, were selected for studying the temperature change. First five stations have database of 105 years, sixth, seventh and eighth stations have database of 45years and the ninth station has the database of 15 years during the period of 1901-2005. Six GCMs simulations wore used for the purpose of model validation and future temperature change for the year 2050. First five stations showed drastic rise of temperature ranging from 1.24-3.67o C in 105 years in the post-monsoon season whereas the stations in the red laterite zone recorded a nominal change of 0 0 temperature ranging from 0.26-0.98 C during 1961-1990. The winter seasons showed the similar warming trend (0.75-2.81 C in 105years) alike post monsoon in the first five stations. Abrupt warming (~0.05-3.03oC) was recorded in last 15 years in the remaining four stations. All GCM models showed a rise of post-monsoon temperature by 0.8-1.8 oC indicating slightly under estimate the observed warming whereas the winter warming is well simulated by GCMs as 1.4-2.4oC. Irrespective of these two 0 seasons, future temperature may rise by 1.4-1.8 C with reference to 1961-90 at end of 2050. This temperature may rise have an important effect on growth and productivity of crops sown during October-March.