资源环境科技发展态势分析平台

This study evaluates the validity of the Integrated Multi-satellite Retrievals for Global Precipitation Measurement (IMERG) in scaling extreme precipitation with temperature (termed scaling factor, SF). To this end, we use Hadley-Integrated Surface Database (HadISD) dataset at 1-hourly, 6-hourly, and 24-hourly scales between 2000-2020 over the contiguous United States (CONUS) as a reference dataset. Our findings reveal that IMERG can capture changes in precipitation extremes with the temperature at 6-hourly, and 24-hourly scales, especially over dry regions. The difference between IMERG’s SF and HadISD’s SF at 6-hourly scale is less than 0.3%/°C in dry areas. However, IMERG underestimates SF in wet regions, especially at 1-hourly scale, up to ∼5%/°C. It is found that IMERG’s performance is dependent on temperature, particularly at 1-hourly scale. IMERG overestimates extreme precipitations when temperatures are below 5-11 ^oC while the opposite is true at higher temperatures, indicating the need for considering temperature in adjusting IMERG.