The Global Precipitation Climatology Project (GPCP): Current Status and Transfer to Operations at NCDC

Homogenized, quality controlled datasets are hugely important for studies wishing to accurately quantify trends and variability in the global climate system. As such, the creation and routine production of Climate Data Records (CDRs) for essential climate variables such as precipitation has become a high priority for the climate community. One such example of a long-standing CDR is the Global Precipitation Climatology Project (GPCP) which has been in continuous production since the late 1990s and offers a 33+ year record of globally complete precipitation by merging the highest quality satellite and gauge estimates to produce a the highest quality, homogenous dataset. The GPCP datasets (monthly, pentad and daily) are very heavily used with over 1500 journal citations.

A project is currently underway, funded by NOAA's National Climatic Data Center (NCDC), to transfer routine processing (and reprocessing) from the various GPCP centers to a single processing center at NCDC. The multi-sensor nature of GPCP is its primary strength, but the collection and merger of these different input datasets provides a unique challenge. Up to now, the processing of GPCP has been executed at several different centers where experts are able to process and check data and then supply rainfall rates to the merge center. In many cases, this involves a high level of manual intervention in both running and quality controlling the products. The NCDC project involves streamlining and better organizing the legacy code that handles every aspect (from brightness temperature to final product) of GPCP v2.2 and transferring that code to NCDC for full archive of the GPCP. Automated quality assurance checks will be a part of the NCDC system.

One of the goals of transferring operations to NCDC is that it will allow the GPCP team to focus on the development of the next generation of merged precipitation datasets (GPCP V3). This presentation will outline the goals and current progress of the effort to transfer V2.2 to NOAA/NCDC as well as outlining some of the plans for the next generation of GPCP.