India as a hotspot for air pollution has heavy black carbon (BC) and dust (DU) loadings. BC has been identified to significantly impact the Indian climate. However, whether BC-climate interactions regulate Indian DU during the premonsoon season is unclear. Here, using long-term Reanalysis data, we show that Indian DU is positively correlated to northern Indian BC while negatively correlated to southern Indian BC. We further identify the mechanism of BC-dust-climate interactions revealed during COVID-19. BC reduction in northern India due to lockdown decreases solar heating in the atmosphere and increases surface albedo of the Tibetan Plateau (TP), inducing a descending atmospheric motion. Colder air from the TP together with warmer southern Indian air heated by biomass burning BC results in easterly wind anomalies, which reduces dust transport from the Middle East and Sahara and local dust emissions. The premonsoon aerosol-climate interactions delay the outbreak of the subsequent Indian summer monsoon.

The importance of the effects of anthropogenic activities on modulating the global dust cycle has been increasingly recognized. Over the Middle East, we find in observations that there has been a significant decrease in dust optical depth from 2007 to 2019 during which global irrigated areas especially in the Middle East and South Asia have rapidly expanded. Whether irrigation expansion contributes to the decrease of dust in the Middle East is investigated based on observations/reanalyses and global climate model simulations with and without irrigation. Results show that irrigation over the northeast Middle East and Pakistan supplements water to the soil. By increasing local evaporation and moisture advection, irrigation enhances precipitation over the whole Middle East and the northwest Indian subcontinent. As a result, dust wet deposition by precipitation is elevated. Owing to irrigation‐induced land surface cooling, surface wind speed decreases as the planetary boundary layer becomes stable. Along with increased soil moisture, reduced surface wind speed suppresses local dust emissions. Enhanced dust wet deposition and suppressed dust emissions cause atmospheric dust reduction over the Middle East. Vegetation greening in the Middle East as the climate warms has no contribution because there is no obvious trend found in observations.