Inomata Y, Ohizumi T, Saito T, Morohashi M, Yamashita N, Takahashi M, Sase H, Takahashi K, Kaneyasu N, Fujihara M, Iwasaki A, Nakagomi K, Shiroma T, Yamaguchi T
Kanazawa University, Kakuma, Kanazawa, Ishikawa 920-1156, Japan; Asia Center for Air Pollution Research, 1182, Sowa, Niigata, Niigata 950-2144, Japan.
Asia Center for Air Pollution Research, 1182, Sowa, Niigata, Niigata 950-2144, Japan.
Sci Total Environ. 2019 Nov 15;691:779-788. doi: 10.1016/j.scitotenv.2019.07.004. Epub 2019 Jul 6.
High emissions of air pollutants from Northeast Asia are strongly influenced by air quality as well as by ecosystems. This study investigated the spatiotemporal variations in the sulfur isotopic ratio (δS) in atmospheric deposition at eleven monitoring stations in Japan from 2011 to 2016 and estimated the amount of transboundary transported anthropogenic sulfate (TRB) deposition using mass balance calculations. The δS of sulfate in precipitation ranged from -0.42 to +22.7‰. Sea salt (SS), TRB, and domestic anthropogenic sources (DOM) were the dominant sources of sulfate deposition in Japan. TRB sulfate deposition was largest on the Sea of Japan side, with an annual average value of 1.5 ± 0.3-6.9 ± 0.5 mg m d (36-44%), followed by Mt. Happo (4.5 ± 0.1 mg m d; 88%), the Pacific Ocean side (1.5 ± 0.8, 4.3 ± 0.9 mg m d; 24-50%), and the remote islands in the North Pacific Ocean (1.1 ± 0.2, 2.0 ± 0.8 mg m d; 19-32%). TRB sulfate deposition on the Sea of Japan side was 2-12 times higher in winter and 1-2 times higher in summer than that of DOM. In contrast, TRB sulfate deposition on the Pacific Ocean side was 1.5-3 times higher in summer than in winter due to high precipitation levels. In Tokyo, the annual contribution from DOM sulfate deposition is approximately three times higher than that from TRB. Annual TRB sulfate deposition is lowest at Ogasawara at 1.1 ± 0.2 mg m d, and the annual oceanic DMS contribution to sulfate deposition is high, accounting for 1.3 mg m d (20 ± 6%). The contribution of Asian dust was estimated to be 1-5.2 mg m d(3-6%), which occurred in a single Asian dust event on the Sea of Japan side.
东北亚地区空气污染物的高排放受到空气质量以及生态系统的强烈影响。本研究调查了2011年至2016年日本11个监测站大气沉降中硫同位素比率（δS）的时空变化，并使用质量平衡计算估算了跨界传输人为硫酸盐（TRB）沉积量。降水中硫酸盐的δS范围为-0.42至+22.7‰。海盐（SS）、TRB和国内人为源（DOM）是日本硫酸盐沉积的主要来源。TRB硫酸盐沉积在日本海一侧最大，年平均值为1.5±0.3 - 6.9±0.5 mg m d（36 - 44%），其次是八方山（4.5±0.1 mg m d；88%）、太平洋一侧（1.5±0.8、4.3±0.9 mg m d；24 - 50%）以及北太平洋偏远岛屿（1.1±0.2、2.0±0.8 mg m d；19 - 32%）。日本海一侧冬季的TRB硫酸盐沉积比DOM高2至12倍，夏季高1至2倍。相比之下，由于降水量大，太平洋一侧夏季的TRB硫酸盐沉积比冬季高1.5至3倍。在东京，DOM硫酸盐沉积的年贡献量约是TRB的三倍。小笠原的年TRB硫酸盐沉积最低，为1.1±0.2 mg m d，海洋二甲基硫（DMS）对硫酸盐沉积的年贡献量较高，为1.3 mg m d（20±6%）。亚洲沙尘的贡献估计为1 - 5.2 mg m d（3 - 6%），发生在日本海一侧的一次亚洲沙尘事件中。
