| 摘要: |
| 黄河口邻近海域海冰是渤海海冰的一部分,为了解其独特的变化特征及机制,本研究基于北海预报中心提供的黄河口周边海洋台站观测数据以及CMEMS (Copernicus Marine Environment Monitoring Service)全球海冰密集度再分析数据,使用统计分析和两种滑动相关分析,结合小波相干方法及大气过程的影响,得到长期变化分析的结果。黄河口冰情在1979—2020年间整体呈减轻趋势(–0.25%/a),显然其直接因素为局地温度整体升高;海冰密集度与黄河径流量呈明显正相关,相关系数为0.46,其原因为径流增大导致盐度降低,海冰增加;与北极涛动指数(AOI,Arctic Oscillation Index)呈明显负相关,相关系数为–0.44,因为当北极涛动为正位相时,东亚大槽强度减弱,北极冷空气南侵受阻隔,冬季黄河口的整体气温升高,导致海冰减少;1997年和2016年左右与北极涛动的相关性都出现了显著正异常,其原因为两次强厄尔尼诺事件的影响,同时海冰密集度在1985年左右的跃变可能与AOI和黄河径流量的突变有关。短期变化分析的结果显示:从2010年和2020年冬季逐日的典型寒潮过程与海冰密集度的变化分析可知,海冰与前6 d负积温的相关性最大,平均相关系数为–0.77,寒潮的出现时间、强度及间隔,控制海冰的生成,而整体气温的低频变化控制海冰的维持和发展。 |
| 关键词: 黄河口 海冰 变化特征 长期趋势 控制机制 |
| DOI：10.11759/hykx20221104003 |
| 分类号:P731.15 |
| 基金项目:国家重点研发计划项目(2018YFB1502801);三亚崖州湾科技城科技专项项目(SCKJ-JYRC-2022-101);崖州湾科技城南海海洋大数据中心项目(SKJC-2022-01-001) |
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| Analysis of the variations and mechanisms of sea ice change in the sea area near the Yellow River Estuary |
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HU Shi-qiang1, LI Ge2, DENG Yao-cheng1, LIU Juan3, SU Liang4, YU Hua-ming1,5
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1.College of Oceanic and Atmospheric Sciences, Ocean University of China, Qingdao 266100, China;2.North China Sea Marine Forecast Center, Qingdao 266061, China;3.Beijing Institute of Applied Meteorology, Beijing 100029, China;4.Qingdao Supercomputing and Big Data Center, Qingdao 266237, China;5.Sanya Oceanographic Institution, Ocean University of China, Sanya 572025, China
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| Abstract: |
| The sea ice in the sea area proximal to the Yellow River Estuary is a part of the sea ice in the Bohai Sea. In this paper, its unique variation characteristics and mechanisms were explored based on the observation data of the ocean stations around the Yellow River Estuary, employing statistical analysis and two types of sliding correlation analyses integrated with wavelet coherence analysis and the impact of atmospheric processes. The observation data were provided by the North Sea Forecast Center and the reanalysis data of the CMEMS global sea ice concentration. The long-term variation analysis showed a decreasing trend in the ice regime within the Yellow River Estuary (−0.25%/year) between 1979 and 2020; the primary factor contributing to this decrease is the overall increase in local temperature. The sea ice concentration is positively correlated with runoff in the Yellow River due to the increase in runoff and the decrease in salinity, resulting in the increase in sea ice; The sea ice concentration exhibits a considerable negative correlation with the Arctic Oscillation Index (AOI), with a correlation coefficient of −0.44; this can be attributed to the fact that when the Arctic Oscillation is in a positive phase, the strength of the East Asia Trough is weakened, the Arctic cold air is blocked from invading to the south, and the overall temperature of the Yellow River Estuary in winter increases, giving rise to sea ice reduction. Remarkable positive anomalies in the correlation with the Arctic Oscillation were observed around 1997 and 2016 due to the impact of two strong El Niño events exceeding the Arctic Oscillation. Similarly, the marked increase in sea ice concentration around 1985 is mainly attributable to the sudden change in the AOI. According to the short-term change analysis of the daily typical cold wave process in the winter of 2010 and 2020 and the change in sea ice concentration, it can be observed that sea ice exhibits the largest correlation with the negative accumulated temperature of the past six days, with an average correlation coefficient of −0.77. The occurrence, intensity, and interval of the cold wave control sea ice generation, while the low-frequency change in the overall temperature controls sea ice maintenance and development. |
| Key words: Yellow River Estuary sea ice change characteristics long-term trends control mechanism |
