A comparison of model produced maximum and minimum temperature trends with observed trends for the 20th and 21st centuries

Observed changes in maximum and minimum temperatures, and the diurnal temperature range for the 20th century generally show stronger warming in the minimum temperature compared to the maximum temperature, resulting in a decrease in the diurnal temperature range (DTR: max minus min). These observed changes, in particular in the DTR, have been related to observed changes in cloudiness, precipitation, and aerosols. In this study we compare results from our recent work updating observed maximum/minimum/DTR trends for the globe (Vose et al. 2005) with those from a number of general circulation model simulations for the 20th century using observed greenhouse gas and other forcings produced for the IPCC Fourth Assessment Report. In addition to the trend analysis, we also examine characteristics of the diurnal cycle of temperature produced by the models.