First ozone and nitrogen dioxide measurements from MetOp-A

This marks the start of a long-term European commitment to monitor the recovery of the ozone layer and to support the monitoring and forecasting of air quality, both for European citizens and at a global level. The products have been developed by the German Aerospace Center (DLR) in partnership with EUMETSAT’s Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M SAF), which is coordinated by the Finnish Meteorological Institute (FMI). The O3M SAF generates, validates, archives and distributes atmospheric ozone, trace gases, aerosols and surface-ultraviolet radiation data products using measurements from MetOp-A.

GOME-2, a scanning spectrometer, follows on from successful GOME flown on ESA’s ERS-2 satellite launched in April 1995, and provides near-global coverage on a daily basis. The instrument measures profiles of atmospheric ozone and the distribution of other trace gases in the atmosphere that are related to the depletion of ozone in the stratosphere, and to natural and anthropogenic sources of pollution.

The amount of surface ultraviolet radiation is also derived from GOME-2 measurements. The ozone layer at an altitude of 20-30 kilometres shields the Earth from harmful ultra-violet radiation. However, the depletion of this protective ozone layer, which is most noticeable over the Arctic and Antarctic regions, is of particular environmental concern. The resulting increased levels of ultraviolet radiation reaching the surface of the Earth can cause serious damage to human health, agriculture, forests and water ecosystems. High levels of atmospheric pollutants such as nitrogen dioxide produced by fossil fuel combustion, can damage respiratory health and contribute to acid deposition which harms soil and vegetation.

Global Ozone
The first image above shows total ozone in the atmosphere as measured by the GOME-2 instrument on 11 January 2007 during one day of successive orbits of MetOp-A. This picture illustrates the large variability within the ozone layer, with ozone-rich air at the northern mid-latitudes and smaller levels of ozone over the (sub)-tropical region. GOME-2 monitors the ozone layer amount from day to day on a global basis, and will track the evolution of the ozone-hole above Antarctica during austral spring.

Regional Nitrogen dioxide
The image shows total nitrogen dioxide in the atmosphere over Europe on 4 February 2007, as measured by the GOME-2 instrument on MetOp-A. Nitrogen dioxide is one of the most important contributors to air pollution. With the GOME-2 instrument, nitrogen dioxide can be measured worldwide on a daily basis, and at a city-size scale. Clearly visible in this picture are high tropospheric nitrogen dioxide concentrations over large urban and industrial areas of Europe. Note that the pollution patterns seen on a daily basis are also affected by the prevailing weather conditions and the resulting movement of clean and polluted air.