Climatic Effects of Ice Nucleation by Typical Natural and Anthropogenic Aerosols in East Asia Using a Developed Version of RegCM‐Chem

Abstract Aerosol‐ice cloud interaction represents a critical issue in the climate system. Unlike warm clouds, ice clouds still lack parameterizations in current Regional Climate and Chemistry Model (RegCM‐Chem), leading to uncertainties in investigating the regional climate in East Asia. This study introduces an ice‐nucleation parameterization into RegCM‐Chem to investigate the climatic effects of ice nucleation by typical natural (dust) and anthropogenic (carbonaceous and sulfate) aerosols. Model results indicate that the ice nucleation of aerosols exerts a radiative heating effect over East Asia. Ice clouds could reflect incoming shortwaves and trap outgoing longwaves simultaneously, with the longwave effect dominant. Dust is the dominant aerosol in the ice cloud effect, contributing ∼70% of the total warming. Dust‐induced nucleation could lead to widespread surface warming (0.17 K) and generates cyclonic anomalies, ultimately resulting in reduced precipitation over inland China (−0.28 mm·day −1 ) and increased precipitation over the Indochina Peninsula and eastern India (0.34 and 0.17 mm·day −1 , respectively). Ice nucleation of typical anthropogenic aerosols might result in cyclonic anomalies over northeastern China and anticyclonic anomaly over southern China. This effect subsequently affects moisture transportation, which suppresses low‐level cloud formation and precipitation over southern China (−0.61% and −0.13 mm·day −1 ) while enhancing them over northeastern China (0.46% and 0.08 mm·day −1 ). The ice cloud effect of anthropogenic aerosols mainly arises from the impact of low‐level clouds on the radiative budget. Changes in low‐level cloud cover are accompanied by an inverse temperature response.