The main scope of this project is to make use of ESA and ESA Third-Party Mission data to establish climate-quality stratospheric data records from satellite instruments for the four essential climate variables of ozone, aerosol, water vapour and temperature.The first priority is to focus on the stratosphere but future potential activities shall also be exploited (e.g. retrieval of temperature information in the upper troposphere). The achievement of the objective shall be pursued through (and not limited to) the following steps:

• to perform a critical review of the requirements for temperature and water vapour CDRs as defined in A1 (see Technical Proposal)
• to identify and explore ESA and ESA-TPM data that could provide essential contributions to this activity but where the quality of the data first needs to be improved (e.g. GOMOS bright limb ozone measurements)
• to identify and collect ESA and ESA-TPM data that have suitable accuracy for this purpose (e.g. GOMOS Level 2 ozone data)
• to do dedicated algorithm development to improve the data quality of selected ESA and ESA-TPM data to make them compliant with accuracy requirements as defined in A1-3
• to establish stratospheric temperature climatologies based on ESA and ESA-TPM data to develop new methods/algorithms to enable the merging of ESA and ESA-TPM data with historical non ESA data sets (e.g. merging of GOMOS ozone data with SAGE data)
• to clearly demonstrate the quality of the newly generated data sets achieved through intercomparison with independent measurements (geophysical validation)
• to define detailed plans for future climate data record generation