Analysis of extreme high temperature conditions over uttar pradesh, india

Abstract

The state of Uttar Pradesh (Fig. 1) is in the heart of Indo-Gangetic plain with river Ganges flowing right through it, Himalayas to the north and the Chota Nagpur plateau and the Vindhya hills to the south. The climate of Uttar Pradesh varies from temperate in eastern Uttar Pradesh, extreme in western UP to semi arid in Bundelkhand and Agra zone. Therefore it is extremely difficult to categorize it in a particular climatic frame. Nevertheless, summers are very hot and winters are chilly. Generally heat waves develop in the north west parts of India or over the northern parts of Pakistan and expand into the neighbouring subdivisions of the country including Uttar Pradesh. Heat wave may also develop in situ over the region in case of development of an upper-air anticyclone circulation. The temperatures start to increase over Uttar Pradesh in March and by April the land area becomes hot with day time maximum temperature reaching about 40 °C at many locations. During this season the range of maximum and minimum temperatures is found to be more than 15 °C at many stations. Maximum temperatures rise sharply exceeding 45 °C by the end of May and early June, resulting in harsh summers particularly over SW-U.P. (Bundelkhand). Heat waves form when high pressure aloft (3,000-7,600 m) strengthens and remains over a region for several days to several weeks. Under high pressure, the air subsides (sinks) toward the surface. This sinking air acts as a dome capping the atmosphere. This cap helps to trap heat instead of allowing it to lift. This results in a continuous build-up of heat at the surface that is experienced as a heat wave.