A study on wind-driven circulation in the subarctic North Pacific using TOPEX/POSEIDON altimeter data
A study on wind-driven circulation in the subarctic North Pacific using TOPEX/POSEIDON altimeter data
复制标题
利用 TOPEX/POSEIDON 高度计数据研究北太平洋亚北极风驱动环流
DOI：
10.1029/97jc00447
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发表时间：
1997
影响因子：
--
通讯作者：
Tokihiro Kono
中科院分区：
文献类型：
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作者：
O. Isoguchi;H. Kawamura;Tokihiro Kono
利用TOPEX/POSEIDON（T/P）高度计资料和欧洲中期天气预报中心（ECMWF）近2年的风场资料，研究了北太平洋副北极地区的时变风驱动环流。海平面距平（SLA）的第一经验正交函数（E1）不包含与空间高度变化（SLA*）有关的变化，它代表一个盆地大小的振荡，与副北极环流的上旋和下旋有关。此外，时间序列的第一个周期对应于Oyashio电流变化的系泊海流计测量约1250米的深度。风应力旋度场的第一和第三个EOF代表了与阿留申低压强度和纬度位置变化相关的盆地大小的南北振荡。风应力旋度距平与SLA* 的主导EOF的时间序列具有较好的相关性，说明SLA* 的主导变化主要受以第一和第三EOF为代表的风应力旋度场的控制。SLA* 的第一个周期的时间序列与由40°N附近风应力旋度估计的Sverdrup输送的时间序列一致，相关系数为0.70。在内部和西部边界区域的T/P SLA导出的输送的标准偏差与Sverdrup输送的标准偏差在同一数量级上是一致的。这些结果表明，在亚北极北太平洋的海面高度变化近似解释的时间相关的风驱动的环流。
Time-dependent wind-driven circulation in the subarctic region in the North Pacific is investigated by using TOPEX/POSEIDON (T/P) altimeter data and European Centre for Medium-Range Weather Forecasts (ECMWF) wind data for about 2 years. The first empirical orthogonal function (EOF) of the sea level anomaly (SLA) without the variation related to the steric height change (SLA*) represents a basin-sized oscillation, which is associated with the spin-up and spin-down of the subarctic gyre. Moreover, the time series of the first EOF corresponds to the Oyashio current variation measured by the moored current meter at about 1250-m depth. The first and third EOFs of the wind stress curl fields represent basin-sized south-north oscillations being associated with changes in intensity and the latitudinal position of the Aleutian low. Time series of both the dominant EOFs of the SLA* and the wind stress curl anomaly are correlated well, which suggests that dominant variation of the SLA* is mainly controlled by the wind stress curl fields represented by the first and third EOFs. The time series of the first EOF of the SLA* is in agreement with that of Sverdrup transport estimated by the wind stress curl near 40°N with a correlation of 0.70. Both standard deviations of the T/P SLA-derived transports in the interior and the western boundary regions are consistent with that of the Sverdrup transport in the same order of magnitude. These results suggest that sea surface height variation in the subarctic North Pacific is approximately explained by the time-dependent wind-driven circulation.