Contributors: Hans Gleisner (DMI)
History of modifications
List of datasets covered by this document
Related documents
Acronyms
General definitions
Scope of the document
This document is the Product Quality Assurance Document (PQAD) for Gridded Tropospheric Humidity Profiles (product C3S_D312b_Lot1.3.3.9) based on GNSS Radio Occultation (RO) measurements. It provides references to descriptions of the product validation methodology. The PQAD is valid for both the Climate Data Records (CDRs) and the corresponding Interim Climate Data Records (ICDRs).
The data products covered by this PQAD are provided as a brokered service from the EUMETSAT ROM SAF. The original ROM SAF documents, to which the present document refers, are the "ROM SAF Validation Report: Reprocessed Level 2B and 2C 1D-Var products [D1], the "ROM SAF Validation Report: Reprocessed Level 3 gridded data" [D2], and the "ROM SAF Validation Report: Interim Climate Data Record (ICDR)" [D3]. They are found at the ROM SAF web site [http://www.romsaf.org|http://www.romsaf.org].
Executive summary
The project C3S_312b_Lot1 includes brokering of tropospheric humidity gridded monthly-mean data from the EUMETSAT ROM SAF. This document refers to the ROM SAF documentation [D1-3] describing the product validation methodology, and providing examples of validation results.
The ROM SAF documentation covers both the CDR (ROM SAF product GRM-29-L3-H-R1) and the ICDR (ROM SAF product GRM-29-L3-H-I1). The CDR covers the time period December 2006 to December 2016, while the ICDR covers the time period from January 2017 and onward, being regularly updated with a two-month delay. The regularly updated ICDR has the same characteristics as the CDR, which has been generated in a ROM SAF reprocessing activity.
1. Validated products
The validation includes the ROM SAF products GRM-29-L3-H-R1 and GRM-29-L3-H-I1, both containing gridded monthly mean tropospheric humidity data and associated variables. These products are described by the ROM SAF Product User Manual [D4].
2. Description of validating datasets
The validation is primarily based on comparisons with ERA-Interim reanalysis data. However, for the ICDR v1.1 (from August 2019 and onward) the validation is made against the ERA5 reanalysis. The reference dataset is described in Sections 2.4 and 4.2 in the ROM SAF Level3 Validation Report [D2], and the consequences of switching from ERA-Interim to ERA5 in August 2019 is described in some detail in Section 3.2 of the ROM SAF ICDR Validation Report [D3].
3. Description of product validation methodology
The validation methodology is outlined in Sections 4.1 and 4.2, and is further discussed in Section 5, of the ROM SAF Level 3 Validation Report [D2].
4. Summary of validation results
The main validation results are summarized in Sections 4.2.5, 5.3, and 7 of the ROM SAF Level 3 Validation Report [D2], and in Section 4 of the ROM SAF ICDR Validation Report [D3].
References
References are found in Section 1.2 of the ROM SAF Level 3 Validation Report [D2] and in Section 1.2 of the ROM SAF ICDR Validation Report [D3].
