The focus of the GHG-CCI project is on deriving parameters from satellite date, which when combined with models can add important missing global information on regional CO2 and CH4 (surface) sources and sinks required for better climate prediction. The ESA project GHG-CCI aims at delivering the high quality satellite retrievals needed for this application. Phase 1 of the GHG-CCI project started in 2010 and Phase 2 commenced in 2014.
The GHG-CCI core ECV data products, generated with ECV Core Algorithms (ECAs), are column-averaged mole fractions of CO2 and CH4 retrieved from SCIAMACHY on ENVISAT and TANSO on GOSAT. Other satellite instruments will be used to provide constraints for upper layers such as IASI, MIPAS and ACE-FTS. The corresponding retrieval algorithms are referred to as Additional Constraints Algorithms (ACAs) within the GHG-CCI project. Important aspects also covered by GHG-CCI are calibration, validation and user assessments.
GHG products & equivalent CMIP5/Obs4MIPs Parameters
The table below shows the GHG outputs that have equivalent CMIP5 parameters and hence are suitable for submission to Obs4MIPs (Observations for Model Intercomparisons), an activity to make observational products more accessible for climate model intercomparisons.
|CMIP5 Table||CMIP5 Matching Parameter : CMIP5 name||CMIP5 Priority|
|Near Surface Sensitive Dry-Air Column-averaged mole Fractions (mixing ratios) of CO2: XCO2 (in ppmv)||Amon||Mole Fraction of CO2 : co2||1|
|Near Surface Sensitive Dry-Air Column-averaged mole Fractions (mixing ratios) of CH4: XCH4 (in ppbv)||Amon||Mole Fraction of CO4 : ch4||1|
Parameter characteristics & GCOS/CMC Requirements
|Split at 3km is arbitrary|
|Types of errors|
|Single sensor uncertainty estimates for every observation (SSEOB)|
|Single sensor accuracy estimates for every observation (SSAOB)|
|Single sensor uncertainty estimates for TCDR (SSECDR)|
|Single sensor accuracy estimates for TCDR (SSACDR)|
|Error covariance matrix for TCDR (ERRCOV)|
|L3 merged product accuracy (ERRMERG)|