Using a geometric eddy identification method, cyclonic and anticycloniceddies from submesoscale to mesoscale in the South Indian Ocean (SIO) havebeen statistically investigated based on 2082 surface drifters from 1979 to2013. A total of 19 252 eddies are identified, 60% of them anticyclonic eddies. For thesubmesoscale eddies (radius r<10 km), the ratio of cyclonic eddies(3183) to anticyclonic eddies (7182) is 1 to 2. In contrast, the number ofanticyclonic and cyclonic eddies with radius r≥10 km is almost equal.Mesoscale and submesoscale eddies show different spatial distributions.Eddies with radius r≥100 km mainly appear in the Leeuwin Current, a bandalong 25° S, Mozambique Channel, and Agulhas Current, areascharacterized by large eddy kinetic energy. The submesoscale anticycloniceddies are densely distributed in the subtropical basin in the central SIO.The number of mesoscale eddies shows statistically significant seasonalvariability, reaching a maximum in October and minimum in February.
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机译：利用几何涡旋识别方法，基于1979年至2013年的2082个表面漂移物，对南印度洋（SIO）中亚尺度到中尺度的旋风和反旋风涡进行了统计研究。总共鉴定出19 252个涡流，其中60％是反气旋涡流。对于亚中尺度的涡流（半径 r <10 km），旋风涡流（3183）与反旋风涡流（7182）的比率为1到2。相反，半径 r ≥10km几乎相等。中尺度和亚中尺度涡流表现出不同的空间分布。半径 r ≥100km的涡流主要出现在莫桑比克25°S附近的吕温海流中海峡和阿格拉哈斯潮流地区以大涡动能为特征。亚中尺度的反气旋旋涡分布在中央情报区中部的亚热带盆地中，中尺度旋涡的数量具有统计上的显着季节性变化，在十月达到最大值，二月达到最小值。
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