The Newly Released Global Precipitation Climatology Project (GPCP) V3.3 Daily and Monthly Products and the Future Plans

The Global Precipitation Climatology Project (GPCP) provides a widely used satellite–gauge merged precipitation dataset designed to meet Climate Data Record (CDR) standards for long-term consistency and homogeneity. The latest release, Version 3.3 of the GPCP Daily (1998–2024) and Monthly (1983–2024) products, issued in February 2025, represents the final generation before the transition to GPCP Version 4. This presentation summarizes the V3.3 products and their satellite–gauge inputs, compares them with Version 3.2, and highlights major updates. It also includes evaluations over the global oceans using Passive Aquatic Listeners (PALs), buoys, and atolls, assessments over sea ice using snow-depth data from ICESat-2, CryoSat-2, and ERA5, and analyses over Antarctica using CloudSat, together with insights from GPM Version 07. Key upgrades in GPCP V3.3 include adoption of GPROF 2021 for passive microwave retrievals, a revised ocean climatology based on updated GPM and TRMM radar and microwave data, sensor-specific adjustments to GPROF-calibrated PERSIANN-CDR, and the introduction of a new absolute bias error variable. Relative to V3.2, V3.3 shows an approximately 11% increase in global ocean precipitation and a 9% global increase, driven mainly by ocean changes, while land precipitation changes are small (about 1%). Initial ocean evaluations using limited in situ data indicate a slight overestimation in V3.3, although energy-budget closure supports the overall increase. Interannual variability is also slightly larger, while regional and global precipitation trends remain largely unchanged. Enhancements in the GPCP V3.3 Daily product stem from updates to the Monthly analysis and incorporation of IMERG V07B Final Run, which uses GridSat to extend daily coverage back to January 1998 through May 2000. The presentation concludes with plans for GPCP V4, focusing on higher resolution, lower latency, and more advanced retrieval and gauge-analysis techniques.