Climate monitoring and climatic change

The earth climate shows great variability over different time scales spanning from decades to thousands of years and more. Past climate are studied by analysing ice cores, sea/lake sediments, shorelines movements, tree pollen, etc.. Numerical experiments are also run in which a Global Circulation Model is used to explore the possible climatic changes related to, e.g. to the earth axis oscillations. The knowledge of past climate can help in predicting the future. Abrupt changes may serve in the identification of thresholds values that can trigger a non-linear behaviour of the earth system (and hence may cause high variations). The overlapping of climate variability on different time scales is the very challenge in predicting climatic changes.

A fundamental role in the determination of the earth climate is played by the solar radiation reaching the earth affecting the ground surface energy balance. The radiation spectrum at the earth is strongly influenced by atmospheric constituents: not only the amount of radiation but also its spectral distribution is crucial.

Present relevant climatic issues concern man-induced climatic change as well as interannual climatic variability (e.g. El Nino). In this section various themes are addressed with attention on the application of ERS data.

Index

The ESA programs related to ozone and other atmospheric constituents monitoring

ERS data for El Nino - Southern Oscillations (ENSO) monitoring

The ESA programs related to ozone and other atmospheric constituents monitoring

Ozone monitoring is important at stratospheric level as well as in the troposphere. An increase of the solar UltraViolet component, related to the "ozone hole" is harmful for the biosphere, while the tropospheric ozone is a pollutant. Ozone chemistry includes other atmospheric trace gases that have to be monitored as well.

The ESA program for continuous monitoring of the ozone and of other atmospheric constituents has begun with the launch of the ERS-2 satellite (1995), carrying a new instrument: the GOME (Global Ozone Monitoring Experiment). Its potential for atmospheric monitoring is becoming more and more evident. A more sophisticated instrument: the SCHIAMACHY, is planned to be launched in 1999, on the ENVISAT platform. A GOME2 instrument is planned to be flown on the European METOP series.

Keywords: ESA European Space Agency - Agence spatiale europeenne, observation de la terre, earth observation, satellite remote sensing, teledetection, geophysique, altimetrie, radar, chimique atmospherique, geophysics, altimetry, radar, atmospheric chemistry