Abstract The quantitative and qualitative characterization of ions and inorganic nitrogen in precipitation assists in understanding the accompanying sources and chemistry of regional precipitation. A total of 212 event-based precipitation samples were collected from four sites in Bangladesh in 2017 to investigate the physicochemical characteristics, sources, and deposition of atmospheric ionic constituents and inorganic nitrogen. During the entire monitoring period, 5.7% of the total samples were acidic (i.e., pH Cox's Bazar > Dinajpur > Sylhet, whereas the anthropogenic species exhibited the order of Dinajpur > Satkhira > Sylhet > Cox's Bazar, underlining the local and regional impacts of these species in Bangladesh. Based on the source apportionment, the sources were categorized as marine (Na+ and Cl−), terrigenous (Ca2+, Mg2+, and HCO3−), fossil fuel combustion (NO3− and SO42−), agriculture (NH4+), and biomass burning (K+). The Cl− in Sylhet and Satkhira suggests additional sources associated with anthropogenic activities. The back-trajectory analyses and the National Centers for Environmental Prediction's final (NCEP FNL) datasets illustrate the presence of significantly diverse air masses with contributions from various sources in the monsoon and non-monsoon climates. Both the amount of precipitation and the ionic quantity governs the fluxes in Bangladesh. The Na+ % and SAR lie under the safe category suggesting a good precipitation water quality for agriculture and soil in Bangladesh, while the deposition of inorganic nitrogen has resulted in a value above the threshold line (10 kg ha−1 y−1). Thus, this study conveys a comprehensive picture of the ionic composition, providing a baseline dataset to assess the atmospheric environment in this lowland region.

中文翻译：

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孟加拉国主要离子成分和无机氮的大气湿沉降：对时空变化和来源分配的影响

摘要 降水中离子和无机氮的定量和定性表征有助于理解区域降水的伴随来源和化学性质。2017 年从孟加拉国的四个地点总共收集了 212 个基于事件的降水样本，以研究大气离子成分和无机氮的理化特征、来源和沉积。在整个监测期间，总样本的 5.7% 是酸性的（即 pH 值 Cox's Bazar > Dinajpur > Sylhet，而人为物种表现出 Dinajpur > Satkhira > Sylhet > Cox's Bazar 的顺序，强调了这些对当地和区域的影响孟加拉国的物种。根据来源分配，来源分为海洋（Na+ 和 Cl-）、陆源（Ca2+、Mg2+ 和 HCO3−)、化石燃料燃烧（NO3− 和 SO42−）、农业 (NH4+) 和生物质燃烧 (K+)。Sylhet 和 Satkhira 中的 Cl− 表明与人为活动相关的其他来源。反向轨迹分析和美国国家环境预测中心 (NCEP FNL) 的最终数据集说明了在季风和非季风气候中存在来自各种来源的显着不同的气团。降水量和离子量都控制着孟加拉国的通量。Na+ % 和 SAR 属于安全类别，表明孟加拉国农业和土壤的降水水质良好，而无机氮的沉积导致值高于阈值线 (10 kg ha-1 y-1)。因此，