XI. Heidelberger Graduiertenkurse Physik

Satellite observations of atmospheric trace gases

Thomas Wagner
Uni Heidelberg

Major topics of current atmospheric research include climate change and human influence on the atmospheric trace gas composition as well as possible feedback mechanisms between both phenomena. Studies of these problems require measurements and modelling studies on a global scale.

Since 1995 a new generation of UV/vis satellite instruments for the global monitoring of atmospheric trace gases are in operation: Global Ozone Monitoring Experiment (GOME), 1995 – present; SCanning Imaging Absorption SpectroMeter for Atmospheric ChartographY (SCIAMACHY), 2002 – present. In contrast to earlier satellite instruments they measure a large variety of atmospheric trace gases (like O₃, NO₂, SO₂, BrO, H₂O, HCHO, OClO, O₂, O₄), which are partly located also in the troposphere, the lowest layer of the atmosphere (about 0 - 10 km altitude). Such measurements allow the investigation of several important aspects:

-Stratospheric O₃ (-hole) chemistry

-Tropospheric pollution (traffic, power plants, etc.)

-The oxidation capacity of the atmosphere

-Biomass burning

-Intercontinental transport of pollutants 

-Clouds and aerosols and their impact on the radiative transfer and energy balance of the atmosphere

The detailed analysis of these aspects includes also the comparison of the satellite measurements with data from atmospheric models and other independent measurements (e.g. from ground or balloon).

The lesson includes the following parts: 

A) Overview on the atmospheric radiative properties and composition. Summary of the current research topics in atmospheric composition and climate change.

B) Overview on remote sensing methods

C) Spectral analysis of UV/vis satellite observations

D) Modelling of the radiative transfer through the atmosphere, influence of aerosols and clouds