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Extended range prediction of heat waves in India

Monday 13 May 2019, 16:00 - 17:00
SEE seminar rooms 1 & 2
Dr Atul Kumar Sahai, Indian Institute of Tropical Meteorology

Joint ICAS/ Priestley Seminar


Heat waves are one of the hazardous extreme weather events that happen during March-June (MAMJ) in India. Most parts of the country suffers from heat waves during this period, with high frequency over north, northwest, central and the eastern coastal regions of India. Studies indicate that with increasing global warming/climate change, the frequency and intensity of heat waves will increase. Therefore, understanding and predicting the extreme temperatures leading to heatwaves, are of greatest importance.

A criterion has been developed based on the observed daily gridded maximum temperature (Tmax) datasets for the period 1981-2010. According to the proposed criterion, a heat wave day is identified when the Tmax is either (1) equal to or more than its climatological 95th percentile (averaged over March-June and during 1981-2010), (2) more than 36°C and (3) the departure from normal is more than 3.5°C, Or, directly when the Tmax is more than 44°C. Three heat wave prone regions, namely, northwest, southeast and northwest-southeast regions are recognized and heat wave spells are identified for each region during 1981-2018. It is noticed that the multi-model ensemble prediction system, developed at Indian Institute of Tropical Meteorology, India has reasonable skill in predicting the heat waves over heat wave prone regions of India. Based on the forecast verification of heat wave spells during the period 2003-2018, it is found that the newly proposed prediction system has great potential in providing an overall indication about the onset, duration and demise of the forthcoming heat wave spell with sufficient lead time with some spatio-temporal error.


Dr. A. K. Sahai, is a senior scientist at Indian Institute of Tropical Meteorology, Pune. He has obtained his M. Sc. Degree in Mathematics from the University of Allahabad and also completed Ph. D. in 1992 from the same University.  Dr. A. K. Sahai has made significant contribution in the field of climate science through his research on understanding, predictability and operational prediction of rainfall/temperature on different time scales focusing over Indian Region. He also specializes in the application of non-linear methods in understanding several aspects of Indian summer monsoon. He made noteworthy contribution in understanding regional aspects of climate change over Indian subcontinent. He has published more than 100 scientific research papers in peer reviewed journals and provided guidance to several M. Sc./M. Tech. and Ph. D. students.

Dr Sahai has done pioneering work in developing a Dynamical Ensemble Prediction System for the extended range prediction of intraseasonal fluctuation over Indian continent under the Monsoon Mission Program of Ministry of Earth Sciences. The system has been found very skilful/useful in predicting 2-4 weeks in advance, the onset, active/break spells and withdrawal phases of the Indian summer monsoon and is also successful in predicting heavy rainfall events, cold waves, heat waves, Madden-Julian Oscillation, cyclogenesis and fluctuations in summer/winter monsoon. Due to the remarkable skill of this system, it has been awarded the ISO 9001:2008 standard certification in the year 2016, and has been transferred to India Meteorological Department for operational use. These forecasts are extensively used in Agriculture, Hydrology, Health, Energy and disaster management. Keeping in view of his active role in Indian climate services and forecasting community, and several original research contributions, he was given additional charge as Head of Climate Research and Services of India Meteorological Department Pune, and also Co-ordinator of India-UK Water Centre.

Considering his scientific contributions, he has been conferred with various awards, viz., IITM Silver Jubilee award in 2003 and 2008, IITM Golden Jubilee award in 2017, Certificate of Merit Award of Ministry of Earth Sciences (MoES), and many visiting fellowships. He has been nominated in various WMO experts team including Member of Scientific Steering Committee of World Weather Research Programme. He is also working as an Associate Editor of Journal of Earth System Sciences and been invited to write review articles in national and international journals/books.

Dr. Sahai has served as the Chairman of Indian Meteorological Society (IMS), Pune Chapter during 2014-2016, and is currently the Vice-President of IMS National council. He has worked extensively for popularization of meteorology in society through IMS.