Upper-air temperature changes in models and radiosonde observations

Despite significant surface warming, earlier radiosonde datasets showed only minimal warming in the troposphere in the satellite era, in contrast to model projections showing greater warming in the troposphere than at the surface. The data also showed greater than expected cooling in the tropical stratosphere. Newer homogeneity-adjusted datasets show increased warming trends in the troposphere and reduced cooling trends in the stratosphere. We compare NOAA's RATPAC temperature data for the troposphere and stratosphere to coupled climate model simulations produced for the fourth IPCC report. Removal of inhomogeneities in the radiosonde data generally improves agreement between trends in the observations and those in the models, but differences remain.