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 User Guide and Specification (PUGS) for Gridded Tropospheric Humidity Profiles (product C3S_D312b_Lot1.3.3.9) based on GNSS Radio Occultation (RO) measurements. It provides a brief guide to the use of the data product, and describes the contents and format of the data files. The PUGS is valid for both the Climate Data Records (CDRs) and the corresponding Interim Climate Data Records (ICDRs).
The data products covered by this PUGS are provided as a brokered service from the EUMETSAT ROM SAF. The original ROM SAF user manuals, to which the present document refers, are the "ROM SAF Product User Manual: Level 1B and 2 products [D1] and the "ROM SAF Product User Manual: Level 3 gridded products" [D2]. 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 monthly-mean humidity data from the EUMETSAT ROM SAF. This document refers to the ROM SAF documentation [D1,2] providing a user guide and data format specification of the brokered water vapour data products.
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. Tropospheric Water Vapour Profiles
1.1 Product description
The input data to the ROM SAF processing, as well as the auxiliary data used in the retrieval process, are described in Section 3 of the ROM SAF Level 1B and 2 PUM [D1] and in Section 3 of the ROM SAF Level 3 PUM [D2]. The gridded data product brokered by the C3S project is specifically described in Section 4.2.7 of the ROM SAF Level 3 PUM [D2].
1.2 Target requirements
Section 4.2 of the ROM SAF Level 3 PUM [D2] states rough target accuracies used for monitoring of the operational data generation. The actual estimated accuracies are often better than this. Estimates of the measurement uncertainties and sampling errors are delivered as parts of the data product. Section 4.2 of the ROM SAF Level 3 PUM [D2] also lists fundamental properties of the data, such as spatial and temporal coverage.
1.3 Data usage information
The gridded tropospheric humidity monthly-mean data are described in the ROM SAF Level 3 PUM. The data product itself is described in Section 4.2.7, the file formats and products contents are described in Section 5, and the data quality and limitations are described in Section 6 [D2].
2. Data access information
The product availability from the ROM SAF is described in Section 7 of the ROM SAF Level 3 PUM [D2]. However, the data are also available in the C3S Climate Data Store through a brokered service.
Appendix A - Specifications for Tropospheric Water Vapour Profiles
The netCDF file format, the applicable conventions, and the contents of the data files, are described in Section 5 of the ROM SAF Level 3 PUM [D2].
References
References are found in Section 1.2 of the ROM SAF Level 3 PUM [D2].
