# Satellite Climate Data Records: Development, Applications, and Societal Benefits
## 3 CDR Products and Applications
### CDRs and Scientific Applications
#### 3.1.2 ESA Climate Change Initiative  
Europe Space Agency's (ESA's) Climate Change Initiative (CCI [68]) is making full use of Europe's Earth observation space assets to exploit robust, long-term global records of essential climate variables, such as greenhouse-gas concentrations, sea-ice extent and thickness, and sea-surface temperature and salinity. This sub-section briefly describes some of the CCI initiatives:  
* _Aerosol CCI_: Aerosol CCI [69; 70] was a three year intensive algorithm development effort that incorporated sensitivity analysis, validation and inter-comparison activities [71], along with a round robin exercise of seven different retrieval algorithms [72]. It produced: (1) AOT and Angstrom exponent (AE); (2) Stratospheric extinction profiles and aerosol optical thickness; and (3) Absorbing aerosol index (AAI). AOT/AE datasets are provided for two main purposes: climate aerosol model evaluation, data assimilation into global aerosol re-analysis/forecasting model systems. The stratospheric dataset is provided as a correction to the total column AOT retrievals (mostly relevant in the case of major volcanic eruptions) and for stratospheric climate model evaluation. The AAI dataset so far is the only information for aerosol absorption (though only qualitative at present) has been prepared for comparison to model datasets by developing a model AAI simulator and analyzing major sensitivities. * Fourier Transform Spectrometer (TANSO-FTS) onboard Greenhouse gases Observing SATellite (GOSAT) (2009-ongoing). * _SST CCI_: The first version of the long-term SST CCI Analysis product version are derived from infrared imagery obtained from several Earth-observing satellite missions, combined to give daily, spatially complete information over the global oceans spanning 20 years [74]. The principal recommended applications are for climate research applications requiring \(\sim\)20 years of stable, low bias records of SST. The dataset is particularly valuable if a representation of global SST is required that is independent of _in situ_ SST measurements. * _Ocean-Color CCI_: The ESA-CCI ocean color ECV dataset [75] provides ocean color data, with a focus on Case 1 (open ocean, not coastal) waters, which can be used by climate change prediction and assessment models. The dataset is created by band-shifting and bias-correcting atmosphere corrected MEdium Resolution Imaging Spectrometer (MERIS) and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) data to match Sea-Viewing Wide Field-of-View Sensor (SeaWiFS) data, merging the datasets and computing per-pixel uncertainty estimates. * _CCI Sea Ice Concentration_: ESA-CCI Sea Ice Concentration (SIC) dataset [76] provides SIC and its uncertainties (both in % from 0 to 100) for both Northern hemisphere (NH) and Southern hemisphere (SH). Each file includes daily averaged SIC, processing status, three estimates of uncertainty, flags of SIC values retrieved outside the physical range of 0%-100%, and relevant metadata information. * _CCI Soil Moisture_: This soil moisture product is being developed and provided in the frame of the ESA Climate Change Initiative. The global soil moisture data set has been generated using active and passive microwave space-borne instruments and covers the 35-year period from November 1978 to December 2013 [77]. * _CCI Land Cover_: ESA--Land Cover (LC) CCI databases [78] consist of: (a) three global LC maps at 300 m spatial resolution for three epochs centered on the years 2010 (2008-2012), 2005 (2003-2007) and 2000 (1998-2002). The maps were obtained using the full MERIS archive (2003-2012) and the Satellite Pour l'Observation de la Terre (SPOT)-Vegetation time series.