| 摘要: |
| 采用1°×1°温度、盐度和流场格点数据,对1993-2022年南太平洋热带-副热带区(SPTS)表层强化的Charney型斜压不稳定的长期变化趋势及其机制进行了分析。发现南太平洋热带区(SPT)生长率表现出显著的减少趋势,每十年减少0.12%,而南太平洋副热带区(SPS)生长率则表现出显著的增加趋势,每十年增加0.10%。上述生长率的变化趋势与卫星观测的涡旋动能(EKE)的变化趋势一致,且SPT的斜压不稳定的变化受剪切和层结的共同调控,而SPS的斜压不稳定的变化主要受剪切的影响,说明斜压不稳定性的变化体现了温盐和流场变化的综合效应。进一步分析发现,上述生长率及EKE的变化趋势与局地有效位能(APE)的趋势一致,突显了斜压不稳定性在能量转移转化中的关键作用。 |
| 关键词: 斜压不稳定 中尺度涡旋 涡动能 有效位能 |
| DOI： |
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| 基金项目:国家自然科学基金项目（面上项目，重点项目，重大项目） |
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| SOUTH PACIFIC TROPICAL-SUBTROPICAL REGION BAROCLINIC INSTABILITY MULTIDECADAL TRENDS AND MECHANISMS ANALYSIS |
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liudandan1, zhushanliang1, liuchuanyu2, fengling2
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1.Qingdao University of Science and Technology;2.Key Laboratory of Ocean Circulation and Waves, Institute of Oceanology, Chinese Academy of Sciences
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| Abstract: |
| Using 1°×1° gridded data of temperature, salinity, and current fields, the long-term trend and mechanisms of surface-enhanced Charney-type baroclinic instability in the tropical-subtropical region of the South Pacific (SPTS) from 1993 to 2022 were analyzed. It was found that the growth rate in the tropical South Pacific (SPT) exhibited a significant decreasing trend, with a reduction of 0.12% per decade, while the growth rate in the subtropical South Pacific (SPS) showed a significant increasing trend, with an increase of 0.10% per decade. These trends in growth rates were consistent with the trends observed in eddy kinetic energy (EKE) from satellite observations. The changes in baroclinic instability in the SPT were jointly regulated by shear and stratification, while the changes in the SPS were primarily influenced by shear. This indicates that the variations in baroclinic instability reflect the combined effects of temperature, salinity, and current field changes. Further analysis revealed that the trends in growth rate and EKE were consistent with the trends in local available potential energy (APE), highlighting the critical role of baroclinic instability in energy transfer and conversion. |
| Key words: baroclinic instability mesoscale eddies eddy kinetic energy available potential energy |