Occurrence of More Heat Waves Over the Central East Coast of India in the Recent Warming Era

Abstract

The increased temperature and humidity in the atmosphere under global warming is the primary cause of the upsurge of heat waves in the tropical belt. The central east coast of India (CECI; Odisha, Andhra Pradesh, and Telangana) is one of the most heavily affected areas in terms of casualties due to heat waves during pre-monsoon (March–May; MAM). Thus, there is a need to analyze the characteristics of pre-monsoon weekly maximum temperature (Tmax) and associated heat waves over the CECI. In the present study, characteristics of weekly Tmax from 23 March to 31 May over the CECI associated with heat waves have been analyzed using the India Meteorological Department gridded (1o × 1o) analysis data set of daily maximum temperature for the period 1980–2015. The recent changes in the weekly Tmax and frequency of various heat-wave spells (1-, 2-, 3-, and 5-day) were also evaluated. The results suggest that the climatological weekly Tmax along the coastal region is less than that in the interior parts for all 10 weeks, and the inter-annual variability and coefficient of variation exhibit similar patterns. The continuous increase in Tmax and its variability is observed as the season progresses, leading to increased intensity and frequency of heat waves in most parts of the CECI. In the recent period, a notable increase in the weekly Tmax and its variability has been observed over most parts of the CECI that has resulted in more heat waves. This study is very beneficial for determining the effects on various sectors for the planning of adaptation methodologies through appropriate strategies for a tolerable future over the CECI in the context of global warming.