Intercontinental difference in extreme weather events for the Northern Hemisphere over the past half century

Abstract:

Weather events that are located in the tails of a weather distribution are called weather extremes. Weather extremes, including severe drought, flooding, heat and cold waves, usually can cause greatest damage to human lives and properties, and have profound implication on ecosystem productivity and carbon cycles. There is mounting evidence suggests that the frequency of temperature and hydrological weather extremes have steadily increased over the last decades, largely due to the ongoing climate change. On the other hand, the distribution and trend of weather extremes can be regionally heterogeneous, which have not been well understood. Here we investigate the spatial distribution and temporal trend of weather extremes in the Northern Hemisphere (NH) over the past half century (1961-2010), with emphasis on the intercontinental comparisons. Our results suggest that warming extremes have increased significantly in East Asia and West Europe; while coldness extremes have decreased globally. Heavy precipitation extremes significantly increased in eastern Northern America, boreal Eurasia, and some parts of China; while drought events showed an increasing trend in northern China-southern Mongolia and some parts of western United States. Our results highlight the regional difference in the trend of weather extremes, which need to be incorporated in the mitigation measures.