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| 基于高度计观测和模式数据诊断南大洋主要锋面与涡旋的特征 |
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周润洁1,2, 王天宇1, 杜岩1,2,3
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1.热带海洋环境国家重点实验室 中国科学院南海海洋研究所, 广东 广州 510301;2.中国科学院大学, 北京 100049;3.南方海洋科学与工程广东省实验室, 广东 广州 511458
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| 摘要: |
| 锋面和涡旋是南大洋重要的中尺度过程，南极绕极环流（Antarctic Circumpolar Current，ACC）系统中的锋面及其裹携的涡旋构成了能量和物质的东向传播通道，对全球大洋的能量和物质平衡具有重要影响。基于海表高度计和B-SOSE（Biogeochemical Southern Ocean State Estimate，B-SOSE）数据，文中分别对南大洋3条主要锋面2013-2017年的分布特征以及近25 a（1993-2018年）涡旋特征进行了统计分析，结果表明：受背景流场的影响，三条主要锋面的纬度位置均会随时间发生变化，其中亚南极锋（Subantarctic Front，SAF）纬度摆动幅度最大，5年内最大摆幅为18°。就锋面强度而言，极锋（Polar Front，PF）强度最大，其能达到的平均深度显著大于其他锋面的影响深度。同时，还统计了1993-2018年间南大洋60 717个涡旋，这些涡旋平均存活时间、平均传播距离和平均半径均明显小于全球涡旋平均值，其中被ACC裹携的36 934个东移涡旋（占南大洋涡旋总数的61%）的时间和空间特征尺度则更小。 |
| 关键词: 南大洋 锋面 涡旋 统计特征 |
| DOI：10.11759/hykx20210204002 |
| 分类号:P731.21 |
| 基金项目:科技部重点研发项目（2018YFA0605700）；区域联合基金-青年基金项目（2019A1515110963）；国家自然科学基金（42106022）；中国科学院战略性先导科技专项和重点项目（XDA15020901，133244KYSB20190031，ZDRW-XH-2019-2）；南方海洋科学与工程广东省实验室（广州）重大专项团队项目（GML2019ZD0303，2019BT02H594）；热带海洋环境国家重点实验室自主项目（LTOZZ2002）联合资助 |
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| Statistical characteristics of major fronts and eddies in the Southern Ocean based on altimetry observations and a model dataset |
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ZHOU Run-jie1,2, WANG Tian-yu1, DU Yan1,2,3
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1.State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China;2.University of Chinese Academy of Sciences, Beijing 100049, China;3.Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou 511458, China
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| Abstract: |
| Fronts and their entrapped eddies are important mesoscale processes in Antarctic Circumpolar Current (ACC) systems. The fronts and eddies constitute the eastward pathway of energy and mass fluxes in the Southern Ocean, contributing to global energy and material balance. In this study, we analyzed the characteristics of Southern Ocean's fronts in 2013-2017 and eddies in the recent 25 years (in 1993-2018) based on altimeter data and Biogeochemical Southern Ocean State Estimate data. Our results show that the front-location latitudes vary with changes in background flows. Among the major fronts, the Subantarctic Front has the largest swing, with a range of 18° within 5 years. As for the frontal velocity strength, the Polar Front (PF) is the strongest. The average depth that the PF can extend is significantly deeper than that of other fronts. The statistics for eddies are based on 60 717 eddies identified in the Southern Ocean from 1993 to 2018. The average statistical values of these eddies are significantly lower than those of global eddies, for example, lifetime, distance, and radius. In particular, there are 36 934 eastward eddies (accounting for 61% of the total Southern Ocean eddies) counted in ACC that are smaller on both space- and time-scale. |
| Key words: Southern Ocean front mesoscale eddy statistical characteristic |