Variability in North Atlantic heat content and heat transport in a coupled ocean–atmosphere GCM
Variability in North Atlantic heat content and heat transport in a coupled ocean–atmosphere GCM
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海洋-大气耦合 GCM 中北大西洋热含量和热传输的变化
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
R. Sutton
中科院分区：
文献类型：
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作者：
B. Dong;R. Sutton
利用海-气耦合环流模式研究了北大西洋上层海洋热含量(OHC)、海表面温度(SST)和海洋热输送(OHT)的变化以及三者之间的关系。我们发现，OHC异常和盐度异常在北大西洋副热带环流周围反气旋传播。它们在中纬度向东传播，在低纬度向西传播。异常流对平均温度的平流和平均流对温度异常的平流都是造成这种纬向传播的原因。除了纬向传播外，上层海洋温度异常还在北大西洋东部向南传播，在那里俯冲起主导作用。大西洋中向北的OHT的变化主要是由海洋环流的变化而不是温度的变化决定的。OHT值的波动是湾流延伸区OHC和SST异常的主要原因。年际变化和年代际变化都是如此。然而，在年际时间尺度上，地表通量也有很大的贡献。对OHT与OHC和SST的关系的分析表明，对OHT波动的了解可以用来提前几年预测OHC的变化，从而预测海表面温度的变化。
Abstract.A coupled ocean–atmosphere general circulation model has been used to study the variations of North Atlantic upper ocean heat content (OHC), sea surface temperature (SST) and ocean heat transport (OHT), and the relationships between these three quantities. We find that OHC anomalies, and salinity anomalies, propagate anti-cyclonically around the North Atlantic subtropical gyre. They propagate eastward in midlatitudes and westward in low latitudes. Both the advection of mean temperature by anomalous currents and the advection of temperature anomalies by mean currents are responsible for these zonal propagations. In addition to zonal propagations, upper ocean temperature anomalies propagate southward in the eastern North Atlantic, where subduction plays a dominant role. Variability in the northward OHT in the Atlantic is primarily governed by variability in the ocean circulation rather than variability in temperatures. Fluctuations in OHT are the major cause of anomalies in OHC and SST in the Gulf Stream extension region. This is true both for interannual variability and for decadal variability. On interannual time scales, however, surface fluxes also make a significant contribution. Analysis of the relationships of OHT with OHC and SST suggests that a knowledge of OHT fluctuations could be used to predict variations in OHC, and therefore sea surface temperatures, several years in advance.