Review of trend detection methods and their application to detect temperature changes in India

SummaryPresent study performs the spatial and temporal trend analysis of annual, monthly and seasonal maximum and minimum temperatures (tmax, tmin) in India. Recent trends in annual, monthly, winter, pre-monsoon, monsoon and post-monsoon extreme temperatures (tmax, tmin) have been analyzed for three time slots viz. 1901–2003, 1948–2003 and 1970–2003. For this purpose, time series of extreme temperatures of India as a whole and seven homogeneous regions, viz. Western Himalaya (WH), Northwest (NW), Northeast (NE), North Central (NC), East coast (EC), West coast (WC) and Interior Peninsula (IP) are considered. Rigorous trend detection analysis has been exercised using variety of non-parametric methods which consider the effect of serial correlation during analysis. During the last three decades minimum temperature trend is present in All India as well as in all temperature homogeneous regions of India either at annual or at any seasonal level (winter, pre-monsoon, monsoon, post-monsoon). Results agree with the earlier observation that the trend in minimum temperature is significant in the last three decades over India (Kothawale et al., 2010). Sequential MK test reveals that most of the trend both in maximum and minimum temperature began after 1970 either in annual or seasonal levels.

► Review of methods for trend detection in the presence of serial correlation.
► Identification of temporal and spatial changes in maximum and minimum temperature over India.
► More than one method should be used to detect temporal changes satisfactorily.
► Substantial change in minimum temperature during 1970–2003 over India.
► Significant temporal changes in temperature are found over North Central region of India.