Department of Earth System Science, Ministry of Education Key Laboratory for Earth System Modeling, Institute for Global Change Studies, Tsinghua University, Beijing, 100084, China.
Department of Atmospheric Sciences, Texas A&M University, College Station, TX, 77843, USA.
Nat Commun. 2022 Apr 5;13(1):1839. doi: 10.1038/s41467-022-29468-1.
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.
印度作为空气污染的热点地区，其大气中含有大量的黑碳（BC）和粉尘（DU）。BC 已被确定为对印度气候有重大影响。然而，BC 与气候的相互作用是否在季风前季节调节印度 DU 尚不清楚。在这里，我们利用长期再分析数据表明，印度 DU 与印度北部的 BC 呈正相关，而与印度南部的 BC 呈负相关。我们进一步确定了 COVID-19 期间揭示的 BC-粉尘-气候相互作用的机制。由于封锁，印度北部的 BC 减少，导致大气中的太阳加热减少，青藏高原（TP）的地表反照率增加，从而引起大气下降运动。来自 TP 的冷空气与受生物质燃烧 BC 加热的温暖的印度南部空气一起导致东风异常，从而减少了从中东和撒哈拉地区的尘埃输送以及本地尘埃排放。季风前气溶胶-气候相互作用延迟了随后的印度夏季季风的爆发。
