Overview of the mesospheric temperature trend and factors of uncertainty

The mesosphere is gradually gaining importance under the new concept of global change debate in recent time. The analysis of systematic changes and trends in the temperature of the mesosphere and lower thermosphere (MLT) has not been as comprehensive as in the lower part of the atmosphere. The reported results on temperature trends in this region are diverse and not much effort was made until recently to synthesize these results to present a global picture. It appears that the understanding of several sources of uncertainties, their bias characteristics and subsequent corrections are the key for correct attribution of mesospheric temperature trend from the existing data sets. The interactive model study is essential component to enhance our knowledge in understanding the observed features in the vertical distribution of trends. This article briefly describes some important factors of errors, which are likely to contaminate the observed data and play a major role in temperature trend analysis. It also summarizes the similarities and differences in various results on temperature trend for MLT region obtained by both experimental and model studies. (C) 2002 Elsevier Science Ltd. All rights reserved.