Impact of preceding winter sea surface temperature on the spring smoke aerosol dipole over the Indochina Peninsula

IF 4.4 2区地球科学 Q1 METEOROLOGY & ATMOSPHERIC SCIENCES

Atmospheric Research Pub Date : 2025-09-26 DOI:10.1016/j.atmosres.2025.108513

Yurun Liu , Ke Gui , Quanliang Chen , Liangliang Feng , Hengheng Zhao , Ruowen Yang , Huizheng Che

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引用次数: 0

Abstract

Smoke aerosols from biomass burning (BB) in the Indochina Peninsula (ICP) constitute a globally significant source of absorptive aerosols, substantially impacting regional climate and air quality. Over the past four decades, the second dominant mode of spring smoke aerosol distribution over the ICP has exhibited a characteristic north-south dipole pattern. To investigate its driving mechanisms, this study analyzes smoke aerosols and meteorological variables using climate statistics (1980–2024), with a focus on interactions among sea surface temperature (SST), atmospheric circulation, and smoke absorptive aerosol optical depth (SAAOD). Results demonstrate high sensitivity of the SAAOD dipole to meteorological conditions: positive SAAOD anomalies in the northern ICP correspond to decreased humidity, elevated temperatures, and reduced precipitation, while negative anomalies in the southern ICP correlate with increased humidity, enhanced upward motion, and greater precipitation. Singular value decomposition (SVD) analysis reveals a significant correlation (correlation coefficient = 0.41) between the interannual variability of the SAAOD dipole and preceding winter SST anomalies in the Arabian Sea (AS), Bay of Bengal (BOB), and South China Sea (SCS). Mechanistically, warm SST anomalies in these regions drive anomalously strong equatorial westerlies, triggering a coupled cyclone system spanning the BOB and SCS. Convergence of BOB-derived westerly moisture and SCS-derived easterly moisture over the southern ICP fuels intense convection and high precipitation, suppressing BB. Moreover, warm SST anomalies induce a meridional overturning circulation, causing downdrafts over the northern ICP. The anomalous cyclone over the SCS enhances transport of dry continental northeasterlies to the northern ICP. These winds warm the leeward slopes of the Yungui Plateau, generating localized hot, dry conditions conducive to BB.

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冬季前海面温度对中南半岛春季烟雾气溶胶偶极子的影响

印度支那半岛（ICP）生物质燃烧（BB）产生的烟雾气溶胶是全球重要的吸附性气溶胶来源，对区域气候和空气质量产生重大影响。在过去的40年里，春季烟尘气溶胶分布的第二主导模式呈现出典型的南北偶极子模式。为了探讨烟雾气溶胶的驱动机制，本研究利用1980-2024年的气候统计数据分析了烟雾气溶胶与气象变量的关系，重点研究了海表温度（SST）、大气环流和烟雾吸收气溶胶光学深度（SAAOD）之间的相互作用。结果表明，SAAOD偶极子对气象条件具有较高的敏感性：ICP北部的SAAOD正异常对应湿度减少、温度升高和降水减少，而ICP南部的SAAOD负异常对应湿度增加、上升运动增强和降水增加。奇异值分解（SVD）分析表明，SAAOD偶极子的年际变化与阿拉伯海（AS）、孟加拉湾（BOB）和南海（SCS）冬季海温异常具有显著的相关（相关系数= 0.41）。从机制上讲，这些地区温暖的海温异常驱动了异常强烈的赤道西风带，引发了一个跨越BOB和SCS的耦合气旋系统。在南ICP上空，由bob引起的西风水汽和由scs引起的东风水汽的辐合引发了强对流和强降水，抑制了BB。此外，温暖的海温异常引起经向翻转环流，导致北ICP上空的下降气流。南海上空的异常气旋增强了干燥大陆东北风向北ICP的输送。这些风使云贵高原的背风斜坡变暖，产生局部炎热干燥的条件，有利于BB的形成。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Atmospheric Research 地学-气象与大气科学

CiteScore

9.40

自引率

10.90%

发文量

460

审稿时长

47 days

期刊介绍： The journal publishes scientific papers (research papers, review articles, letters and notes) dealing with the part of the atmosphere where meteorological events occur. Attention is given to all processes extending from the earth surface to the tropopause, but special emphasis continues to be devoted to the physics of clouds, mesoscale meteorology and air pollution, i.e. atmospheric aerosols; microphysical processes; cloud dynamics and thermodynamics; numerical simulation, climatology, climate change and weather modification.