The Day-to-day Variability of Mesospheric Water Vapor at High Latitude - a Comparison Between Microwave Observations and Calculations by Means of the GCM LIMA
Abstract
Water vapor measurements in the mesosphere employing the microwave technique were carried out in high latitudes at ALOMAR (69.29 N, 16.03 E), Norway. The observed water vapor mixing ratios are marked by pronounced variations with planetary time scale. As the chemical lifetime of water vapor is very large in the mesosphere the variations reflect transport processes triggered by the planetary wave activity. A prominent signature is the quasi 5-day wave, actually having a period varying around this value. Using our real-date GCM LIMA (Leibniz-Institute Middle Atmosphere model) of the Leibniz-Institute of Atmospheric Physics in Kühlungsborn, Germany, the model output satisfactory reproduces the measured variations although in detail various differences occur between observations and calculations. In particular, the annual variation including intra-annual variations as caused by sudden stratospheric warmings is mirrored by the model. We discuss the results for different years in terms of dynamics and chemistry.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2007
- Bibcode:
- 2007AGUFM.A43A0865S
- Keywords:
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- 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0317 Chemical kinetic and photochemical properties;
- 0322 Constituent sources and sinks;
- 0340 Middle atmosphere: composition and chemistry;
- 0341 Middle atmosphere: constituent transport and chemistry (3334)