Heat waves and cold spells in a warming climate

This study investigates trends and uncertainties in heat waves and cold spells in a warming climate at decadal and regional scales in the 21st century. Projections of heat waves and cold spells are developed by analyzing temperature outputs from the Community Climate System Model version 3 (CCSM3) forced with IPCC SRES scenarios. Standard definitions of temperature extremes used in the prior literature are used directly or further developed in this study. Reanalysis data from the National Center for Environmental Prediction (NCEP) are used to compare with model simulations and produce estimates of bias and uncertainty. The differences in climate model projected extremes versus proxies of observations based on reanalysis are investigated in detail at regional and decadal scales and as functions of related variables. Known trends in climate extremes are confirmed while new and interesting insights are suggested.