Performance of IMERG as a Function of Spatiotemporal Scale

Area of Science:

• * Earth Science
• * Atmospheric Science
• * Hydrology

Background:

• * The Integrated Multi-satellitE Retrievals for GPM (IMERG) provides global, high-resolution gridded precipitation data.
• * Applications in hydrology and climate modeling require precipitation estimates at various spatial and temporal scales.
• * Scaling precipitation data can impact its reliability.

Purpose of the Study:

• * Evaluate the performance of IMERG Final Run precipitation estimates.
• * Assess IMERG's reliability across different spatial resolutions and accumulation periods.
• * Compare IMERG with ground-based measurements and the TRMM Multi satellite Precipitation Analysis (TMPA).

Main Methods:

• * Evaluated IMERG performance against ground-based radar and gauge data.
• * Analyzed performance across spatial resolutions (0.1° to 2.5°) and accumulation periods (0.5 h to 24 h).
• * Included TMPA as a benchmark for comparison.

Main Results:

• * Both IMERG and TMPA showed improved performance with increased spatial and temporal scales.
• * Rain occurrence identification and rain rate errors (systematic and random) improved at coarser scales.
• * IMERG generally demonstrated slightly better performance than TMPA.

Conclusions:

• * IMERG reliability is scale-dependent, generally improving at coarser resolutions and longer accumulation periods.
• * IMERG is a reliable dataset for hydrological and climate studies, with performance insights provided for various scales.
• * Users can leverage these findings to understand IMERG's suitability for their specific research needs.