Ozone is strongly linked to climate due to its influence on Earth’s radiative budget, absorbing solar UV radiation in the stratosphere and terrestrial infrared radiation in the troposphere. Due to these dual processes, the climate impact of changes in ozone concentrations varies with the altitude.
Human-produced chlorine and bromine-containing gases are responsible for major ozone losses in the lower atmosphere resulting in a cooling effect on the Earth's surface. In contrast, increases in tropospheric ozone, a result of air pollution, have a warming effect on the Earth's surface, thereby contributing to the greenhouse effect.
The Ozone project has been part of the ESA Climate Change Initiative (CCI) programme since it was initiated in early 2010. This project focuses on the generation of multi-decadal time series of harmonised and consistent ozone data suitable to assess long-term changes in the total ozone column, the tropospheric ozone column as well as its vertical distribution across the UT/LS and stratosphere.
Ozone_CCI climate data records are based on satellite nadir sensors such as GOME, SCIAMACHY, GOME-2, IASI, OMI and TROPOMI complemented by a series of limb-viewing instruments allowing for a comprehensive characterization of the ozone columns and vertical profiles at various horizontal scales. These data products are freely distributed to the international user community and several of these feed the Copernicus Climate Change Service (C3S).
Main activities include
- Development of state-of-the-art level-2 and level-3 ozone retrieval algorithms
- Long-term data record generation and reprocessing of historical data sets
- Data characterisation and uncertainty analysis including geophysical validation
- Fully traceable documentation on all steps of the data generation
- User assessment by the project Climate Research Group (CRG) and the Climate Modelling User Group (CMUG)
The Ozone CCI project’s objectives are:
- Develop advanced level-2 and level-3 retrieval algorithms applicable to nadir and limb sensor types, and apply them to long times-series of measurements with the aim to realize the full potential of existing and historical sensors
- Improve the information content of ozone measurements in critical altitude regions (troposphere and UTLS) using the synergy between nadir and limb-type sensors
- Link European data records to historical non-European data series to create consistent long-series of observations covering several decades, as required for climate change-related studies
- Bring a significant impact on ozone related research at the international level, through active involvement in the WMO/GAW Scientific Assessments of Ozone Depletion, that are compiled every four years