北极河流径流对北冰洋环流的影响

田霏; 王召民; GavilanEstanislao; 刘成彦

doi:10.3969/j.issn.0253-4193.2020.07.001

北极河流径流对北冰洋环流的影响

doi: 10.3969/j.issn.0253-4193.2020.07.001

田霏^{1, 2,},
王召民^{1, 2, ,},
GavilanEstanislao^{1, 2},
刘成彦^{1, 2, ,}

1.
河海大学海洋学院国际极地环境研究实验室，江苏南京 210098
2.
南方海洋科学与工程广东省实验室（珠海），广东珠海 519082

基金项目: 国家科技部国家重点研发计划项目（2016YFA0601804）；国家自然科学基金（41876220）；中央高校基本科研业务费专项资金（B200202143）。

详细信息

作者简介:
田霏（1996—），女，湖南省临湘市人，从事极地海洋研究。E-mail：tianfei@hhu.edu.cn

通讯作者:
王召民（1963—），男，江苏省徐州市人，从事海洋环流与全球气候变化、大气−海洋−海冰相互作用、海洋环流高分辨率数值模拟、气候模式发展与气候模拟等研究。E-mail：zhaomin.wang@hhu.edu.cn

刘成彦（1983—），男，江苏省徐州市人，从事极地海洋、海冰、大气和冰架相互作用研究。E-mail：chengyan.liu@hhu.edu.cn

中图分类号: P731.27
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出版历程
- 收稿日期: 2020-01-08
- 修回日期: 2020-04-26
- 网络出版日期: 2020-11-18
- 刊出日期: 2020-07-25

Effects of the Arctic river runoff on the Arctic Ocean circulation

Tian Fei^{1, 2
,},
Wang Zhaomin^{1, 2
, ,},
Gavilan Estanislao^{1, 2},
Liu Chengyan^{1, 2
, ,}

1.
International Polar Environment Research Laboratory, College of Oceanography, Hohai University, Nanjing 210098, China
2.
Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, China

摘要

摘要: 北极河流径流是北冰洋淡水的最大来源，其变化会对北冰洋中的诸多过程有重要影响。本文基于全球高分辨率海洋−海冰耦合模式的模拟结果，研究北冰洋温盐、海冰以及环流对北极河流径流的敏感性。通过对比有气候态北极河流径流输入的控制实验结果和径流完全关闭的敏感性实验结果，研究发现北极径流对北冰洋温度、盐度、海冰以及海洋环流等有显著的影响。关闭北极河流径流后，在河口附近的陆架上温度降低、盐度升高，且导致500 m深度处温度下降以及盐度升高；河口附近的陆架处，海冰密集度与海冰厚度增加。关闭北极河流径流也对北冰洋内的环流有影响：由于缺少来自欧亚大陆的北极径流的输入，穿极漂流与东格陵兰流流速减小且盐度增加；关闭北极径流导致近岸海表面高度降低，沿欧亚陆架的北冰洋边界流减弱，白令海入流增强。通过对比关闭北极径流实验与控制实验的温度和盐度剖面，发现关闭北极径流后大西洋层温度降低，各陆架海盐跃层的梯度减小，盐跃层厚度减小。
- 北极河流径流 /
- 海洋环流 /
- 水团 /
- 海冰
Abstract: River runoff plays a dominant role in the freshwater flux to the Arctic Ocean, and the corresponding changes in river runoff may have important effects on many processes in the Arctic Ocean. In this study, the sensitivity of ocean temperature, salinity, sea ice and circulation to river runoff was investigated by using a global high-resolution coupled ocean-sea ice model. By comparing the simulated results from a sensitivity experiment without river runoff with the results from a control simulation with climatology river runoff, we found that the river runoff can significantly modulate the temperature, salinity, sea ice, and ocean currents in the Arctic Ocean. In the sensitivity experiment without river runoff, the sea surface temperature on the shelf near the estuaries decreases, and the salinity increases. At 500 m depth, the temperature decreases, and the salinity increases in the sensitivity experiment. The sea ice concentration and thickness also increase near the estuaries in the sensitivity experiment. The shutdown of the river runoff also has an impact on the circulation, which leads to weaker and fresher East Greenland Current and the Transpolar Drift Stream. The shutdown of runoff forcing can also slow down the Arctic Circumpolar Boundary Current along the Eurasian Shelf and speed up the Bering Strait inflow by lowering the sea surface height in the shelf seas. In the sensitive experiment, a colder Atlantic layer, a smaller salinity gradient and a thinner upper halocline can be identified by comparing with the temperature and salinity profiles from the control experiment.
- Arctic river runoff /
- oceanic circulation /
- water masses /
- sea ice

HTML全文

图 1 北冰洋地形图

蓝色填充方块表示模式中径流数据的输入点，红色直线划分了各个陆架海的区域，黑色和红色实线包围的区域为计算北冰洋温度与盐度垂直廓线的区域。黑色点1（72.51°N，151.75°W）与黑色点2（79.13°N，128.62°E）是在加拿大海盆和欧亚海盆边缘选取的两个代表性站点，通过这两个站点的温度与盐度剖面来分析关闭河流径流实验中表层海水的潜沉能力。蓝色镂空方框是计算白令海峡、弗拉姆海峡、北冰洋环极边界流与穿极漂流区域平均的区域

Fig. 1 The Arctic Ocean bathymetry

The blue solid rectangles represent the input points of the runoff data in the model. The red line divides the regions of each marginal sea. The regions bounded by black and red lines are the regions where the hydrographic profiles of the Arctic Ocean are calculated. Black point 1 (72.51°N，151.75°W) and black point 2 (79.13°N，128.62°E) are two points selected at the edge of the Canadian Basin and Eurasian Basin. We analyze the subsidence capacity of the surface water through the temperature and salinity profiles of these two points in the experiment without river runoff. The open blue boxes are the areas of computing the regional averages of the Bering Strait, Arctic Circumpolar Boundary Current and the Fram Strait and Transpolar Drift Stream

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图 2 不同实验中北冰洋的海冰范围（a）、海冰厚度(b)、动能(c)及热含量(d)

动能和热含量均做了深度积分。图中的黑色直线分割了实验运行的前10年与后10年，本文主要分析1989−1998年的变化

Fig. 2 Sea ice extent (a), sea ice thickness (b), kinetic energy (c) and thermal content (d) for the Arctic Ocean from the different experiments

The kinetic energy and thermal content are integrated deeply. The black vertical line in the figure divides the first and last decade of the experiments. We mainly analyze the changes from 1989 to 1998

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图 3 控制实验A中10年平均表层温度（a）和盐度（c），控制实验A和PHC3.0气候态表层温度（b）和盐度（d）的差值

最大的温度和盐度的差值都出现在陆架上，分别为−2.5℃和7.7

Fig. 3 Time-mean (1989−1998) sea surface temperature (a) and salinity (c) in the control experiment A, and the anomalies between the control simulation and PHC3.0 of sea surface temperature (b) and salinity (d)

The largest temperature and salinity biases in the Arctic Shelf regions are −2.5℃ and 7.7, respectively

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图 4 控制实验A 10年平均与PHC3.0气候态数据集在北冰洋整体区域平均的位势温度（a）与盐度（b）廓线对比

Fig. 4 Vertical profiles of annual mean potential temperature (a) and annual salinity (b) averaged over the Arctic Ocean during the period of 10 years from the control experiment A

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图 5 控制实验A的10年平均混合层深度(a)、海冰密集度(b)、海表洋流速度场(c)和海表面高度(d)

Fig. 5 10 years mean of the mixed later depth (a), the sea ice concentration (b), the sea surface velocity fields (c), and the sea surface height (d) from the control experiment A

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图 6 控制实验A中500 m水深10年平均位势温度(a)、盐度(b)和速度场(c)

Fig. 6 10 years means of the potential temperature (a), the salinity (b), and the velocity (c) at 500 m depth in the control experiment A

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图 7 表层（a）与500 m水深（b）10年平均位势温度差（关闭河流实验B减去控制实验A）

Fig. 7 10 years mean differences of the potential temperature at surface (a) and 500 m depth (b) (the results from the sensitivity experiment B minus the control experiment A)

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图 8 表层（a）与500 m水深（b）10年平均盐度差（关闭河流实验B减去控制实验A）

Fig. 8 10 years mean differences of the salinity at surface (a) and 500 m depth (b) (the results from the sensitivity experiment B minus the control experiment A)

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图 9 冬季（1−3月）（a）、春季（4−6月）（b）、夏季（7−9月）（c）和秋季（10−12月）（d）混合层深度之差（关闭河流实验B减去控制实验A）

Fig. 9 Time mean difference of the mixed layer depth of winter (January−March) (a), spring (April−June) (b), summer (July−September) (c), and autumn (October−December) (d) (the results from the sensitivity experiment B minus the control experiment A)

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图 10 加拿大海盆边缘点1（72.51°N，151.75°W）与欧亚海盆边缘点2（79.13°N，128.62°E）（位置见图1）处，两个实验的密度差、位势温度差与盐度差（关闭河流实验B减去控制实验A）

Fig. 10 The difference of density, potential temperature and salinity between experiments A and B, at Point 1 (72.51°N，151.75°W) and Point 2 (79.13°N，128.62°E) near the edges of Canadian Basin and Eurasian Basin (See Fig.1 for the locations) (the results from the sensitivity experiment B minus the control experiment A)

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图 11 10年平均海冰密集度之差（a）和海冰厚度之差（b）（关闭河流实验B减去控制实验A）

Fig. 11 10 years mean difference in ice concentration (a), and ice thickness (b) (the results from the sensitivity experiment B minus the control experiment A)

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图 12 表层（a）与500 m水深（b）10年平均流速场之差（关闭河流实验B减去控制实验A）

Fig. 12 10 years mean difference of the velocity at surface (a) and 500 m depth (b) (the results from the sensitivity experiment B minus the control experiment A)

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图 13 10年平均海表面高度差（关闭河流实验B减去控制实验A）

Fig. 13 10 years mean difference of the sea surface height (the results from the sensitivity experiment B minus the control experiment A)

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图 14 各边缘海区域平均位势温度廓线对比

Fig. 14 Time-mean profiles of the potential temperature for each marginal sea

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图 15 各边缘海区域平均盐度廓线对比

Fig. 15 Time-mean profiles of the salinity for each marginal sea

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图 16 北冰洋区域平均位势温度（a）和平均盐度（b）廓线对比

Fig. 16 Time-mean profiles for the potential temperature (a) and the salinity (b) in the Arctic Ocean

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