ESTIMATES OF TEMPERATURE TRENDS IN THE FREE ATMOSPHERE FROM REANALYSIS DATA AND RADIOSONDE OBSERVATIONS

V. M. Khan, A. M. Sterin, and K. G. Rubinshtein

Results are presented of the comparison of signs and estimated values of temperature trends in the troposphere and lower stratosphere, as obtained from the NCAR/NCEP reanalysis and radiosonde data. It is shown that, for most areas with a good data coverage, in the upper troposphere and lower stratosphere, the trends derived from the two sources have the same signs. Cooling in the lower tropical stratosphere and warming in the troposphere are confirmed. The temperature trend estimates from the two sources are also close. The conclusion is drawn that the four-dimensional data assimilation scheme used for the NCAR/NCEP reanalysis produces no significant distortions in the upper-air temperature trends, and the reanalysis data can be reasonably used for the trend analysis.