An active role of extratropical sea surface temperature anomalies in determining anomalous turbulent heat flux
An active role of extratropical sea surface temperature anomalies in determining anomalous turbulent heat flux
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DOI：
10.1029/2002jc001750
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发表时间：
2003-10-01
影响因子：
3.6
通讯作者：
Yamane, S
中科院分区：
文献类型：
--
作者：
Tanimoto, Y;Nakamura, H;Yamane, S
[1] 结合北太平洋上空观测到的海面温度异常（SSTA）的主要模式来检查湍流潜热通量异常和感热通量异常的时空结构。通过对观测到的通量异常进行线性化，可以评估观测到的海表温度、地表气温和风速异常在确定异常湍流热通量方面的相对重要性。在北太平洋中央盆地，包括气温和风速在内的大气变量的变化是通过改变湍流热通量而产生局地海温变化的主要原因，这支持了温带海气相互作用的传统观点。相比之下，在海洋动力学对形成海温异常非常重要的地区，初冬形成的海温异常在确定仲冬和晚冬湍流热通量异常方面发挥着主要作用，表明海温对上层大气的强制作用。具体来说，西太平洋亚北极锋区的十年尺度海温异常和日本南部厄尔尼诺相关的海温异常都被发现积极参与对大气的这种强迫。大气对这种强迫的反应似乎包括异常风暴路径活动。观测到的大气异常可能部分是由这两个地区先前存在的海温异常引起的，也会迫使盆地其他部分出现海温异常，从而导致冬季期间观测到的海温异常的时间演变。
[1] Temporal and spatial structures of turbulent latent and sensible heat flux anomalies are examined in relation to dominant patterns of sea surface temperature anomalies (SSTA) observed over the North Pacific. Relative importance among observed anomalies in SST, surface air temperature, and wind speed in determining the anomalous turbulent heat fluxes is assessed through linearizing the observed flux anomalies. Over the central basin of the North Pacific, changes in the atmospheric variables, including air temperature and wind speed, are primarily responsible for the generation of local SST variations by changing turbulent heat flux, which supports a conventional view of extratropical air-sea interaction. In the region where ocean dynamics is very important in forming SSTAs, in contrast, SSTAs that have been formed in early winter play the primary role in determining mid- and late-winter turbulent heat flux anomalies, indicative of the SST forcing upon the overlying atmosphere. Specifically, both decadal scale SSTAs in the western Pacific subarctic frontal zone and El Nino related SSTAs south of Japan are found to be engaged actively in such forcing on the atmosphere. The atmospheric response to this forcing appears to include the anomalous storm track activity. The observed atmospheric anomalies, which may be, in part, forced by the preexisting SSTAs in those two regions, act to force SSTAs in other portions of the basin, leading to the time evolution of SSTAs as observed in the course of the winter season.