大气对黑潮延伸区中尺度海洋涡旋的响应——冬季暖、冷涡个例分析

采用动态合成、带通滤波等方法，通过对冬季黑潮延伸区暖、冷两个中尺度海洋涡旋的分析，研究了大气对中尺度海洋涡旋的响应特征。结果表明，海表温度（SST）与近海面风速的正相关关系在涡旋的动态合成图上清晰可见，暖（冷）涡上空对应10 m风速的极大（小）值，即海洋对大气的强迫作用在日时间尺度上表现显著；SST高低值中心基本对应10 m风无辐散区，暖（冷）涡上空为异常正（负）涡度分布；暖（冷）涡上空潜热、感热通量增大（减小），降低（增大）大气稳定度，从而加强（减弱）边界层垂直混合作用，使得海洋大气边界层增厚（变薄）。暖（冷）涡旋上空对应摩擦速度极大（小）值，反映了湍流粘性力在高（低）海温中心增大（减小）的特征，表明动量垂直混合机制在中小尺度海气相互作用中起着主要作用。中尺度海洋涡旋能够影响大气瞬变扰动，大气瞬变扰动强度在暖（冷）涡下游上空出现极大（小）值，该影响不仅表现在海洋大气边界层，在自由大气中低层也有较为清晰的反映。此外，从能量转换的角度入手，发现斜压能量转换在中尺度海洋涡旋影响大气瞬变扰动强度中贡献明显。

Atmospheric Response to Mesoscale Oceanic Eddies over the Kuroshio Extension:Case Analyses of Warm and Cold Eddies in Winter

The response of the atmosphere to mesoscale oceanic eddies is investigated by using dynamic composite and bandpass filters with particular focus on one warm eddy and one cold eddy over the Kuroshio Extension during the winter season. Results show positive correlation between sea surface temperature (SST) and wind speed at 10-m on dynamic composites, indicating remarkable oceanic forcing at daily time scales. Significantly weak divergence appears over the warm (cold) eddy center with positive (negative) vorticity anomaly. Latent and sensible heat fluxes increase (decrease) over the warm (cold) eddy, thus weakening (enhancing) atmospheric stability and thickening (thinning) the marine atmospheric boundary layer with strong (weak) vertical mixing. The maximum (minimum) center of frictional velocity, which represents turbulent viscous forces, lies over the warm (cold) eddy, indicating the substantial role of the vertical mixing mechanism in mesoscale and microscale ocean-atmosphere interaction. Mesoscale oceanic eddies can exert their influence on atmospheric transient disturbance intensity, which is significant both in the boundary layer and the mid-lower troposphere. Moreover, baroclinic energy conversion is found to play a critical role in the oceanic forcing of atmospheric transient disturbances.