Wang Shanshan, Jiao Liping, Yan Jinpei, Zhao Shuhui, Tian Rong, Sun Xia, Dai Siying, Zhang Xiaoke, Zhang Miming
Key Laboratory of Global Change and Marine Atmospheric Chemistry, MNR, China; Third Institute of Oceanography, Ministry of Natural Resources of China, China.
Xiamen Environmental Monitoring Station, Xiamen, China.
Sci Total Environ. 2024 Nov 1;949:175135. doi: 10.1016/j.scitotenv.2024.175135. Epub 2024 Jul 30.
Marine aerosols (MA) can be influenced by sea ice concentration, potentially playing a pivotal role in the formation of cloud condensation nuclei and exerting an impact on regional climate. In this study, a high-resolution aerosol observation system was employed to measure the concentration and size of aerosols in the floating ice region and seawater region of the Arctic Ocean during the 8th and 9th Chinese Arctic Expedition Research Cruise. The identification of aerosol sources was conducted using a modified positive definite matrix factorization method and a backward air mass trajectory model. Two types of MA including the sea-salt aerosol (SSA) and the marine biogenic aerosol (BA) were identified and their concentrations were calculated. Then the physical-chemical characteristics of MA in the floating ice region and seawater region were compared under normalized conditions (-2.5 °C < T < -0.1 °C; 5.80 m/s < WS < 10.95 m/s) to discern the impact of sea ice. A unimodal distribution was observed for MA number concentration with a dominant peak ranging from 0.5 μm to 1.0 μm in size range. The findings revealed that the presence of sea ice cover led to a significant reduction of 52.2 % in the number concentration of SSA, while exerting minimal influence on its composition. BA number concentration in the floating ice region was 33.3 % higher than that in the seawater region. Strong winds (wind speed >6.5 m/s) transported organic matter and nutrients entrapped in sea ice into the atmosphere, leading to an increase in BA concentration. However, the presence of sea ice cover hampered the exchange of biogenic gases between the ocean and air, resulting in a reduction of secondary BA formation. Our study elucidates the correlation between MA release and sea ice coverage in the Arctic Ocean, thereby establishing a theoretical foundation for climate prediction models.
海洋气溶胶（MA）会受到海冰浓度的影响，可能在云凝结核的形成中起关键作用，并对区域气候产生影响。在本研究中，利用高分辨率气溶胶观测系统，在中国第8次和第9次北极科学考察航次期间，对北冰洋浮冰区和海水区的气溶胶浓度和粒径进行了测量。采用改进的正定矩阵因子分解法和后向气团轨迹模型对气溶胶源进行了识别。识别出了包括海盐气溶胶（SSA）和海洋生物源气溶胶（BA）在内的两种海洋气溶胶类型，并计算了它们的浓度。然后，在归一化条件（-2.5℃<T<-0.1℃；5.80m/s<WS<10.95m/s）下，比较了浮冰区和海水区海洋气溶胶的物理化学特征，以了解海冰的影响。观测到海洋气溶胶数浓度呈单峰分布，主峰粒径范围在0.5μm至1.0μm之间。研究结果表明，海冰覆盖使海盐气溶胶的数浓度显著降低了52.2%，而对其组成的影响最小。浮冰区的生物源气溶胶数浓度比海水区高33.3%。强风（风速>6.5m/s）将海冰中截留的有机物和营养物质输送到大气中，导致生物源气溶胶浓度增加。然而，海冰覆盖阻碍了海洋与大气之间生物源气体的交换，导致二次生物源气溶胶形成减少。我们的研究阐明了北冰洋海洋气溶胶释放与海冰覆盖之间的相关性，从而为气候预测模型奠定了理论基础。
