The GOME ozone monitoring instrument

• General introduction
• Monitoring of ozone and other species
• Example: retrieval of the ozone column from the spectra
• ERS orbit and GOME's global coverage
• Data delivery

Monitoring of ozone and other species

The spectral features around 330 nm, for example, are used to retrieve the ozone column: the total ozone concentration in a column of air between the Earth's surface and the top of the atmosphere. Information about the vertical distribution of the ozone is retrieved from the data in the range between 260 and 350 nm. The ozone columns are combined (by a technique called data assimilation) with a model of the transport of ozone in the atmosphere and the chemical reactions involving ozone. This combination of observations and model results in global ozone maps.

Ozone absorbs ultraviolet (UV) light, and the amount of harmful UV reaching the surface is directly related to the ozone column above. Based on the total ozone column maps, a clear-sky UV-index is computed.

Important for the analysis of the data of ozone and other species is information on clouds, which can be derived from the so-called oxygen-A band around 760 nm.

Monitoring ozone is the primary function of GOME. But the spectra it measures also give unique information on other atmospheric species, such as the total concentration of nitrogen-dioxide, bromine and chlorine species, formaldehyde, sulphur-dioxide and the abundance of aerosols (particles) in the atmosphere. See for example the products at the GOME page of the University of Bremen

Observing the world-wide concentration and distribution of ozone is important to monitor the evolution of the ozone layer, to derive the amount of UV, to provide ozone and UV forecasts, and to improve the weather forecasts. Furthermore, the data sets are of great importance to climate research, as changes in the concentration and distribution of ozone, nitrogen-dioxide and other trace gases reflect possible consequences of human activities on the Earth's atmosphere.

A wide range of important issues is studied based on the data sets provided by instruments such as GOME: the trend in the ozone hole and a possible recovery of the ozone layer in the future; the amount and global distribution of air pollution; changes in the amount of human-related emissions (such as fossil fuel and biomass burning) and natural emissions (e.g. emissions from soils and vegetation, lightning); trends in ozone in the lower atmosphere related to these changes in the atmospheric composition; the relation between changes in ozone and the greenhouse effect; etc.
 

Subjects:

• General introduction
• Monitoring of ozone and other species
• Example: retrieval of the ozone column from the spectra
• ERS orbit and GOME's global coverage
• Data delivery