Chemical characteristics of aerosols transported from Asia to the East China Sea: an evaluation of anthropogenic combined nitrogen deposition in autumn
Chemical characteristics of aerosols transported from Asia to the East China Sea: an evaluation of anthropogenic combined nitrogen deposition in autumn
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DOI：
10.1016/j.atmosenv.2004.11.037
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发表时间：
2005-03-01
影响因子：
5
通讯作者：
Uematsu, M
中科院分区：
文献类型：
--
作者：
Nakamura, T;Matsumoto, K;Uematsu, M
陆地气溶胶沉降是贫营养海洋沃茨污染的主要途径之一。为了了解从亚洲大陆输送到东海沉积的气溶胶的地球化学意义，我们利用白凤丸号（R/V Hakuho Maru）在秋季（沙尘事件较少的季节）对东海上空的气溶胶进行了连续观测，并观测了人为物质的流出。气溶胶中非海盐盐（nss）-SO 42-的平均浓度为8.7 +/- 6.8 μ g m（-3），这是中国南方高度工业化城市地区污染大气的典型值。细态NH 4+主要以（NH 4）（2）SO 4和/或NH 4 HSO 4的形式存在，粗态NH 4+则是由细、粗粒气溶胶中铵离子的交互凝聚形成。另一方面，NO3-的平均浓度（1.8 +/- 1.2 μ g m（-3））低于城市大气中的浓度。非海盐SO_（42-）主要来源于燃烧源和海洋生物过程，后者占0- 38%。估算的东海大气气溶胶NH 4+和NO3-的年沉降通量分别为270 Gg N yr（-1）和160 Gg N yr（-1）。这些大气输入与长江的河流输入相当。总的氮沉降可以解释约2.5 TgC的生物固定（约0.1-9%的新产品）在东海每年，这实际上可能是更大的，因为秋季经历最小的沙尘暴。(c)2005爱思唯尔有限公司保留所有权利。
Deposition of terrestrial aerosols is one of the major means of fertilizing the oligotrophic ocean waters. In order to understand the biogeochemical significance of aerosols transported from the Asian continent, and deposited over the East China Sea, we studied their chemical properties by making continuous measurements on board R/V Hakuho Maru in autumn, a season of lower dust events.Outflows of anthropogenic substances were observed over the East China Sea. The average concentration of non-sea-salt , salt (nss)-SO42- in aerosols was 8.7 +/- 6.8 mu g m(-3) a value typical for polluted atmosphere of a highly industrialized urban area in South China. Fine mode NH4+ mainly occurred as (NH4)(2)SO4 and/or NH4HSO4 while in coarse mode it was formed from intermodal coagulation of ammonium particles in fine and coarse aeorosols. On the other hand, the mean concentration of NO3- (1.8 +/- 1.2 mu g m(-3)) was lower than that in the urban atmosphere. Non-sea-salt SO42- were derived 4 from combustion sources and marine biological processes, the latter accounting to 0-38%. Nitrate in coarse mode was associated with Ca2+ and Na+ perhaps due to replacement reactions.Our estimates of the annual atmospheric aerosol deposition fluxes of NH4+ and NO3- to the East China Sea were 270 Gg N yr(-1) and 160 Gg N yr(-1), respectively. These atmospheric inputs are comparable to the riverine inputs of the Changjiang River. The total combined nitrogen deposition could account for a biological fixation of about 2.5 TgC (approximately 0.1-9% of the new production) in the East China Sea annually, which could actually be larger since the autumn season experience minimal dust storms. (c) 2005 Elsevier Ltd. All rights reserved.