Organic Geochemical Studies of Polar Aerosols : Long distance transport and photochemical transformation of natural and anthropogenic materials

极地气溶胶的有机地球化学研究：天然和人为材料的长距离传输和光化学转化

基本信息

批准号：
06453009
负责人：
KAWAMURA Kimitaka
金额：
$ 5.38万
依托单位：
HOKKAIDO UNIVERSITY (1996)Tokyo Metropolitan University (1994-1995)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1996
项目状态：
已结题

项目摘要

Homologous series of low molecular weight dicarboxylic acids (C2-C11) have been measured in the arctic aerosol samples collected from July 1987 to June 1988 in Alert. Oxalic acid (C2) was found as the dominant species followed by malonic (C3) or succinic (C4) acid. At the time of polar sunrise, certain dicarboxylic acids in arctic haze aerosols became 5 to 20 times more abundant than in the preceding dark winter months. Furthermore, they are correlated with tropospheric ozone depletion events marked by particulate bromine. Here, we report, for the first time, homologous series of dicarboxylic acids in the polar atmosphere and discuss the formation of these organic acids in terms of photochemical oxidation of pollutant precursors that reach the Arctic by long range atmospheric transport from midlatitudes.Antarctic aerosols collected at Syowa Station were also studied for water soluble organic compounds. Total carbon and nitrogen were also determined. Succinic (C4) or oxalic (C2) acid was found as the dominant diacid species followed by azelaic (C9), adipic (C6) or malonic (C3) acid. Concentration range of the total diacids was 5.9-88 ngm-3 with an average of 29 ngm-3. Highest concentrations were observed in the summer sample with a predominance of succinic acid (61.5 ngm-3), which comprised of ca. 70% of the total diacids and accounted for 3.5% of total aerosol carbon (1020 ngm-3). The succinic acid (C4) is likely produced by photooxidation fo 4-oxocarboxylic acids, which are present in the atmosphere as intermediates of the photooxidation of unsaturated fatty acids. These results indicate that the antarctic organic aerosols originate from marine-derived lipids and are transformed largely by photochemical oxidations. w-Oxocarboxylic acids (C2-C9,0.36-3.0 ngm-3) also showed the highest concentration in the summer sample, again suggesting a secondarily production in the atmosphere of the Antarctic and Southern Oceans.

在1987年7月至1988年6月收集的北极气溶胶样品中，已经测量了一系列低分子量二羧酸（C2-C11）的同源系列。草酸（C2）被发现为主要物种，其次是马洛克（C3）或琥珀酸（C4）酸。在极性日出时，北极雾剂气溶胶中的某些二羧酸的丰富性比上一月份的冬季更丰富5至20倍。此外，它们与颗粒溴标记的对流层臭氧耗竭事件相关。在这里，我们首次报道了极性大气中的一系列同源二羧酸，并根据在Syowa Station收集的Syowa Antarosols在Syowa Aerosols中收集的水溶液的污染物氧化剂的光化学前体对这些有机酸的形成。还确定了总碳和氮。发现琥珀酸（C4）或草酸（C2）酸是主要的二酮物种，其次是硫酸二酮（C9），脂肪（C6）或马洛克（C3）酸。总尿素的浓度范围为5.9-88 NGM-3，平均为29 NGM-3。在夏季样品中观察到最高的浓度，琥珀酸占主导地位（61.5 ngm-3），该酸（61.5 ngm-3）由Ca组成。总二肽的70％，占气溶胶总碳的3.5％（1020 NGM-3）。琥珀酸（C4）可能是由4-氧化羧酸的光氧化产生的，它们是在大气中作为非饱和脂肪酸光氧化的中间体中产生的。这些结果表明，南极有机气溶胶起源于海洋衍生的脂质，并主要通过光化学氧化而转化。 W-氧化羧酸（C2-C9,0.36-3.0 NGM-3）在夏季样品中也显示出最高的浓度，再次表明在南极和南方大洋的大气中第二次产生。