WP 3 - Validation Process


The objectives of this workpackage are "to come to a harmonized approach for each ECV/CDR/FCDR", "to propose a distributed validation network and strategy" and to "report on consistency of CDRs". This workpackage will be split into two tasks:

Task 3.1 Coordinating a harmonized approach for validating each ECV/CDR.

The generation of ECVs needs to put strong emphasis on the generation of fully described, error-characterized and consistent satellite-based ECV products. These have to be assessed against the updated maturity index as generated in WP2.

For example, generation of many ECVs (such as in the ESA CCI projects) requires ancillary information about the state of the atmosphere (e.g., cloud screening for SST, atmospheric correction for space-borne altimeters). As such, the consistency between the various ECV products (e.g. cloud flags in one ECV and non flag in another one) extends to ensuring consistency in the approaches of CDR generation.

It is essential that the climate data records of the ECV products measure up to generic verification and validation standards in order to comply with the required maturity index levels. Due to EUMETSAT’s experience in defining scientific procedures to evaluate the quality and the maturity of CDR/ECV products and their vitality for operational and research purposes, they will advise in this work package on generic strategies for verifying and validating FCDRs and TCDRs. EUMETSAT will contribute to the assessment of existing verification and validation methodologies, consulting on which standard metrics, trend models, variability estimators, etc should be used. Building upon this assessment a generic strategy will be suggested for verifying, monitoring, calibrating and validating FCDRs and TCDRs of the ECV products.

A strong coordination will be established with existing activities in coordinating validation processes, in particular with the GMES/COPERNICUS in-situ Coordination (GISC) project.

This will help identify gaps in gridded information in the interactions and exchanges between the domains atmosphere, ocean and land. The closing of the hydrological cycle should receive specific attention, in terms of land and ocean interactions, the runoff from continents should be validated in the gridded reanalysis products. Coordination will take place with the following relevant COPERNICUS projects: MACC II, GeoLand2, MyOcean 2, CARBONES, EURO4M, MONARCH-A, CryoLand and other none COPERNICUS FP7 projects such as ERA-CLIM and ICE2SEA. 

Task 3.2. Analysis of ECV/CDR validation network and strategy.

All ECVs require continued reference measurements for validation and calibration of satellite products. This is also valid for refined satellite products which cannot rely on less exact, older satellite products. These reference measurements are either in-situ measurements that are conducted at representative sites at sufficient number (so-called “Direct Comparison Method”), or Earth observation data from instruments that measure with a superior quality (“Scaling Method”). A different physical measurement principle as the measurements that are being used to generate the ECV product should be used, in order to ensure independency from this product.

European contributions to WGCV (CEOS Working group in Calibration and Validation) current activities are mainly focused on the requirements for validation and calibration identified by the Group on Earth Observations (GEO) and their goal to achieve a Global Earth Observation System of Systems (GEOSS). The WGCV is taking a lead role in the GEO tasks related to this calibration and validation. CORE-CLIMAX will therefore coordinate with the WGCV group's current activities.

Key in situ networks used to ground-truth satellite observations include, but are not limited to, the GCOS Reference Upper Air Network (GRUAN), the Argo Ocean Buoy Network, the AErosol RObotic NETwork (AERONET), WMO’s Global Atmosphere Watch (GAW), Regional Basic Synoptic Network (RBSN) and Regional Basic Climatological Network (RBCN), the CEOS ground-based calibration and validation sites, as well as the Third Pole Environment flagship observation sites on the Tibetan Plateau and surroundings. The combination of satellite products and these in situ observations are essential in order to provide broad spatial coverage, i.e. regional or global, and high measurement accuracy.

As such the coordination activity here will focus on establishing the overall strategy for the validation processes.

Coordination with the FP7 funded “GMES/COPERNICUS In-situ Coordination (GISC)” aiming at an innovative and sustainable framework for open access to in-situ data for the future operational phase of COPERNICUS will take place focusing on validating ECV/CDR/FCDRs. GISC has done a preliminary analysis of the collection, assessment and evaluation of in-situ requirements of the different COPERNICUS services for Land, Marine environment, Atmosphere monitoring and Emergency management as outlined in the GIO regulation (the COPERNICUS programme and its initial operations from 2011–2013 (GIO) to allow an operational COPERNICUS system by 2014. The regulation entered into force in November 2010.). As such, CORE-CLIMAX can benefit by consolidating what has been available . It is noted that the Climate Change service is still in the conceptual phase therefore CORE-CLIMAX will coordinate and identify the capability of ongoing activities and contribute to the formulation of the COPERNICUS climate service theme and lay the observational basis for service activities.

This task will help to substantiate how COPERNICUS observations and products can contribute to climate change analyses, by establishing the extent to which observations complement existing Climate Data Records.

Gaps in the ongoing activities will be identified, thereby contributing to the formulation of the COPERNICUS climate service theme and laying the observational basis for service activities. Apart from recent gaps it is also important to conduct analysis on the continuity of the ECVs in the future, bearing in mind the approaching end of a number of EO satellites (VGT, MODIS, MERIS) and the scheduled launch of new, but similar sensors (OLCI, SLSRT, Proba-V, VIIRS). This task will identify and carry out a user requirements review process to feed the climate monitoring requirements to the COPERNICUS space component. COPERNICUS Climate Services have to impose their requirements into the multipurpose Sentinel missions and other complementary multipurpose missions, such as the operational meteorological missions. As such, this continuity analysis will also benefit the atmosphere and ocean requirements for (future) COPERNICUS missions for climate services.

CORE-CLIMAX will coordinate closely with other initiatives and projects (and in particular FP7 COPERNICUS projects) and identify gaps in gridded information in the interactions and exchanges between the domains atmosphere, ocean and land. The closing of the hydrological cycle will receive specific attention, in terms of land and ocean interactions, the runoff from continental areas will be validated in the gridded reanalysis products. Available discharge data from the Global Runoff Data Centre and from consortium partners will be used to assess the closing of the hydrological cycle in terms of land and ocean interactions as in the gridded reanalysis products. As such CORE-CLIMAX will coordinate to assess the situation within Europe for European producers. We will concentrate on GLOBAL data records with highest priority. Some parameters may only be measured in certain areas, such as snow and ice cover, a field of expertise covered by FMI and the ICPC participants ITP and CAREERI.