Aerosol particles over the Bay of Bengal – characteristic, variability and sources – a comprehensive measurement and analysis approach during the BIOCAT-IIOE2 (Aerosol-BIOCAT)

气溶胶粒子是重要的气候驱动因子，因为它们散射和吸收太阳辐射并影响云的形成和特征。为了更好地了解气溶胶颗粒的各种气候影响，需要对气溶胶的来源和处理过程有一个正确的了解，而这在很大程度上仍然是缺失的。迄今为止，关于气溶胶化学性质在时间和空间分辨率方面的变异性以及关于其混合状态的信息很少。一般来说，大陆和人为排放对海洋上空，特别是印度洋北部上空气溶胶颗粒的影响，人们对其强度了解甚少，量化也很差，因此在估计海洋气溶胶的气候效应方面存在很大的不确定性。在aerosol - biocat项目中，我们的目标是通过应用详细的现场测量和统计分析，填补关于孟加拉湾（BoB）气溶胶颗粒的可变性、来源和环境驱动因素的巨大知识空白。我们将与R/V Sonne （SO305/BIOCAT）和Aerosol-BIOCAT一起参加BIOCAT- iioe2研究巡航，我们将在这次巡航中执行主要的大气研究部分。为此，我们将使用与气溶胶和海洋表面微层（SML）的综合化学特征相关的在线气溶胶物理化学测量的组合。将获得一套独特的气溶胶特征数据集，并将在数据集上执行先进的受体模型，以便在东北季风期间在BoB的两个样带（南北和南北）上定量归因不同的气溶胶源。具有高时间分辨率的物理测量将允许观察气溶胶动力学（例如新粒子的形成）或气溶胶类型之间的转变。对海水的化学分析，特别是对SML的化学分析将提供第一个数据集，该数据集将为从海洋到大气的有机物转移以及BoB地区黑碳向海洋表面的沉积以及SML对冰成核颗粒（INP）的作用提供新的见解。这些调查将有助于正确了解海洋来源，并为TROPOS现有的增强SML数据集增加有价值的信息。总的来说，在提出的项目中，将获得有关东北季候风期间大气气溶胶颗粒的海洋和非海洋来源和进一步处理的新的定量信息。研究结果将有助于缩小关于受污染海洋区域自然（海洋、粉尘）和人为来源重要性的知识差距。预期的结果将对更好地模拟海洋上的粒子传输和改进对其气候影响的预测具有极大的价值。

Aerosol particles are important climate drivers as they scatter and absorb solar radiation and impact the formation and characteristics of clouds. To better understand the diverse climatic effects of aerosol particles, a proper understanding of the aerosol sources and processing is required that is to date still largely missing. Few information on the variability of aerosol chemical properties regarding their temporal and spatial resolution as well as information on their mixing state exist to date. The strength of continental and anthropogenic emissions on the aerosol particles over the ocean in general, and over northern part of the Indian Ocean in particular, is little understood and poorly-quantified, causing strong uncertainties in the estimation of the climate effect of marine aerosols. Within the project Aerosol-BIOCAT we aim to fill the big gaps of knowledge that exist concerning the variability, sources, and environmental drivers on the aerosol particles over the Bay of Bengal (BoB) by applying elaborated field measurements and statistical analysis. We will participate in the BIOCAT-IIOE2 research cruise with R/V Sonne (SO305/BIOCAT) and with Aerosol-BIOCAT we will perform the main atmospheric research component in this cruise. To this end, we will use a combination of online aerosol physico-chemical measurements associated to a comprehensive chemical characterization of the aerosols and the marine sea surface microlayer (SML). A unique data set of aerosol characteristics will be obtained, and advance receptor models will be performed on the dataset allowing a quantitative attribution of different aerosol sources during the North-East monsoon over two transects of the BoB (South-North and North-South). The physical measurements with the high temporal resolution will allow to observe aerosol dynamics (e.g. the formation of new particles) or transitions between aerosol types. The chemical analysis of seawater and especially of the SML will deliver a first-time dataset that will provide new insights into the transfer of organic matter from the ocean to the atmosphere as well as the deposition of black carbon to the ocean surface in the BoB region and the role of SML on Ice nucleating particles (INP). These investigations will allow a proper understanding of marine sources and add valuable information to the enhanced SML dataset existent at TROPOS. Overall, within the presented project new, quantitative information about the marine and non-marine origin and further processing of atmospheric aerosol particles in the BoB during the North-East monsoon will be obtained. The results will help to reduce the gaps of knowledge regarding the importance of natural (oceanic, dust) and anthropogenic sources in polluted marine regions. The expected results will be extremely valuable for better modeling particle transport over the ocean and improve the prediction on their climate effects.