Evaluating the accuracy of APHRODITE and CHIRPS satellite-based Precipitation products for meteorological drought monitoring

The feasibility of calculating the Standardized Precipitation Index (SPI) at different meteorological ground stations (GS) using monthly precipitation data from Satellite-based Precipitation Products (SbPP) was investigated in this study. Iraq was divided into three Köppen climate zones for spatial comparisons. Monthly precipitation time series data from the Asian Precipitation Highly Resolved Observational Data Integration towards Evaluation (APHRODITE) 1983–2007 and Climate Hazards Group of Infra-Red Precipitation with Stations (CHIRPS) 1983–2017 were statistically compared against GS data from the three zones to estimate potential droughts at the timescales of SPI-3, SPI-6, and SPI-12. SbPPs not only had reasonable correlations with GS data, but also effectively represented the spatial distribution of rainfall. There was satisfactory consistency between APHRODITE and GS values in high-rainfall zones in the SPI estimation. This current work also found that APHRODITE was more dependable than CHIRPS when spatially and temporally determining drought over Iraq. These results are particularly significant as Iraq faces the twin difficulties of high drought risk and a lack of accurate meteorological data, making an improvement in monthly precipitation data of vital importance.