What Drives Warming Rates of Extreme Temperatures Relative to the Mean?
This work compares the warming rate of Northern Hemisphere summer hot extremes against the mean. The study finds that the warming rate of hot extremes relative to the mean is determined by the local hydroclimate conditions.
Heat extremes pose significant challenges for different sectors of society and the economy, such as human health, agriculture, animal discomfort, and energy demand. Identifying regions where extremes are rising faster or will rise faster in the future informs decision-makers and policyholders to take necessary steps for planning and adaptation. The physical mechanism identified in this work is useful for process-based evaluation of climate models.
This work examines the warming rate of summertime extreme temperatures relative to the local mean in the Northern Hemisphere. The relative warming pattern of extreme temperatures is analyzed using a generalized extreme value distribution framework. This study shows extreme temperatures are rising slower than the local mean in generally arid and moist regions. In contrast, the extremes are rising faster than the local mean in dry-subhumid regions. The evaluation based on the response of the surface fluxes during mean and extreme heat days suggests that the local hydroclimate conditions drive the relative warming rates of extreme temperatures.