Early Validation of Vertical Profiles from the ENVISAT Atmospheric

• Main Authors: K. H. Fricke, U. Blum
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Andøya; Arctic; Esrange; Kiruna; Norway; Northern Norway
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.212.4774; http://envisat.esa.int/pub/ESA_DOC/envisat_val_1202/proceedings/ACV/ground_based/16_AOID222.pdf

The vertical structure of the terrestrial atmosphere is governed by hydrostatic equilibrium, which relates altitude, temperature, and pressure (or density). The mixing ratios derived for the chemically important trace gases depend on a precise knowledge of this basic atmospheric structure. The Bonn University backscatter lidar on the Esrange (68N, 21E) near Kiruna, Sweden, was operated from mid-July to the end of August 2002 to obtain atmospheric structure data, i.e. altitude profiles of temperature and relative density for Envisat validation. In all we could perform 36 measurement runs with the lidar, of which 34 yielded usable density and temperature profiles as well as several observations of tropospheric and mesospheric clouds. The three Envisat atmospheric instruments Gomos, Mipas, and Sciamachy measure altitude profiles of temperature and density or pressure. This validation report reflects the state of the operational inversion software for these three instruments up to mid-November 2002. Comparisons of 38 Gomos profiles with lidar data in the altitude range 30 to 70 km show the shape of the density profiles to agree to better than 2 % and the mean deviation for temperatures does not exceed 1.4 % or 3-4 K. The Gomos altitude registration agrees with the lidar altitudes to better than 300 m. Independently Envisat instrument profiles were compared to an empirical model of the middle atmosphere in Arctic summer above northern Scandinavia, which is based on a decade with falling sphere measurements from the Andøya Rocket Range in northern Norway. Comparing 48 Gomos profiles to the falling sphere statistics in the altitude range 35 to 93 km