Vol.:(0123456789) 1 3 Meteorology and Atmospheric Physics https://doi.org/10.1007/s00703-018-0621-6 ORIGINAL PAPER Pre‑monsoon rainfall and surface air temperature trends over India and its global linkages Palash Sinha 1  · M. M. Nageswararao 1  · Guru Prasad Dash 1  · Archana Nair 1  · U. C. Mohanty 1 Received: 12 December 2017 / Accepted: 25 June 2018 © Springer-Verlag GmbH Austria, part of Springer Nature 2018 Abstract An evidence of a changing climate is already sensed in India where there is a large diversity from region to region and from season to season. The rainfall pattern in the pre-monsoon (March–April–May) season is important as it helps in determin- ing many crop-related activities in many parts of the country. In the present study, an attempt is made to analyze the current trends in pre-monsoon season rainfall and temperatures over 34 meteorological subdivisions in India using the India Mete- orological Department observed analysis datasets of rainfall (1951–2013) and temperatures (1981–2013). The results suggest that a signifcant decreasing trend in the pre-monsoon rainfall at all-India level and the maximum reduction is found in the month of March. From the regional scale analysis, the south peninsular India is found to have an increasing trend, whereas a decreasing trend is observed over Jammu and Kashmir, Himachal Pradesh and northeast parts of the country. The analyses reveal an association of pre-monsoon rainfall over India with precipitation over China and temperature over the South China Sea, which may act as a precursor for the pre-monsoon rainfall that ultimately could afect the Indian summer monsoon rainfall. The increase of rainfall activity over south peninsular India is attributed to increases in the meridional temperature gradient with an increase of specifc humidity. The results of the study will be useful for a long-term risk management in various sectors and would aid in adapting new technologies for a sustainable development in the changing climate scenario. 1 Introduction There is no doubt that the climate is changing with the warming of the atmosphere and ocean system (Gleckler et al. 2016). Many of the associated impacts such as sea level change, melting of glaciers/ice sheets, and increase in carbon dioxide level in the atmosphere have occurred since 1950s at rates unprecedented in the historical record (Mimura 2013). Evidences of changes in the global water cycle, with an increase in disparity between wet and dry regions, as well as wet and dry seasons have been found (IPCC 2007). The global climate change can result in corresponding changes in precipitation amounts, temperature, and the increase of food/drought events at a regional level as well. It is also noted that increase in heavy precipitation events has been observed even in places where total rainfall amounts have decreased (Trenberth 2005). The IPCC reports stated that India is one such country, which is at a higher risk of cli- mate change. Studies carried out by several investigators (Pant and Rupa Kumar 1997; Arora et al. 2005; Dash et al. 2007, Nageswararao et al. 2015) have shown that the trend and magnitude of warming over India over the last century are broadly consistent with the global trend and magnitude. Pant and Rupa Kumar (1997) noticed an increase in mean annual temperature, at the rate of 0.57 °C per 100 years. A recent study by Kumar et al. (2013) has reported that by the end of the twenty-frst century, a robust increase in monsoon precipitation is likely to occur with regional diferences in strength. Many studies (Goswami et al. 2006; Dash et al. 2009, 2011; Kulkarni et al. 2012; Nageswararao et al. 2016a, 2016b) have clearly highlighted the consistent changes in the amount, intensity and frequency of precipitation events during summer/winter monsoon over India. The trends in pattern, distribution and periodicities of rainfall in southwest monsoon rainfall over India have been addressed by sev- eral researchers such as Guhathakurta and Rajeevan (2008); Kumar et al. (2010). It is clear from the previous studies that the climate change is prevalent in the summer monsoon Responsible Editor: A.-P. Dimri. * U. C. Mohanty ucmohanty@gmail.com 1 School of Earth Ocean and Climate Sciences, Indian Institute of Technology Bhubaneswar, Argul, Jatni, Odisha 752050, India