A Model Study of Heat Waves over North America: Meteorological Aspects and Projections for the 21st Century
The goal of this research is to evaluate the fidelity of GFDL climate models in reproducing the characteristics of summertime heat waves in North America, and to examine the model-projected changes of these characteristics in the 21st century.
North American incurs considerable economic costs due to heat waves. Understanding of the processes contributing to heat waves, and projecting changes in their characteristics in the 21st century, are an integral part of the NOAA mission to provide scientific information on the present and future states of the climate system.
This study analyzes output from comprehensive suites of model experiments with present and future climate settings, and considers heat waves in different parts of North America. It provides spatial and temporal details of the present and future behavior of heat waves.
Output from two climate models with 50- and 200-km resolution (HiRam and CM2.1, respectively) is subjected to rotated empirical orthogonal function analysis, so as to select regions with enhanced and coherent surface temperature variability. A heat wave identification scheme is then applied to these regions using model data for both present and future climate scenarios. Trends of heat wave intensity, duration and frequency are then deduced by comparing the heat wave statistics for the 20th and 21st centuries.
Present findings based on GFDL models need to be compared with those derived from other models. Robustness of the results presented herein needs to the evaluated by application of alternative identification schemes of heat waves.