Spatial analysis of climate change in Inner Mongolia during 1961–2012, China

Abstract

Global warming has changed the distribution of climate resources with previous studies indicating that the arid and semi-arid areas have become drier because of decreasing precipitation. Based on daily meteorological data collected at 46 meteorological stations in Inner Mongolia, we analyzed the spatial distribution and trends of major climate variables (precipitation, daily mean, minimum and maximum temperatures) at monthly and annual scales over the past 52 years. Variation of humid index was also analyzed.An increasing trend was identified for the daily mean temperature in the study area, and the trend (0.37 °C/decade) is higher than the global warming rate (0.14 °C/decade). Compared to daily mean temperature and daily maximum temperature, daily minimum temperature showed a greater increasing trend (0.51 °C/decade). As for most stations, the largest trends for daily mean, minimum and maximum temperatures occurred in the last ten days of February. Through a series of regression analyses, it was found that the change of vapor pressure had a high correlation coefficient with temperature trends and both temperature and vapor pressure showed the strongest increasing trend in February. Annual precipitation showed a slightly decreasing trend, mainly because of a decrease of precipitation in July and August. Forty-three out of 46 stations exhibited negative slopes in the time series of humid index, which indicates that Inner Mongolia has become drier in the past 52 years.In summary, Inner Mongolia has become warmer and drier with increasing temperature and decreasing precipitation during the past several decades.