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海气交界面的能量交换与海洋平流共同决定海表面温度(sea surface temperature,SST)异常的形成、维持与衰减。基于作者近期的研究,本文回顾了海表面热通量(surface heat flux,SHF)反馈以及SST方差与海表热通量及海洋热输送方差之间的关系。海表热通量异常可近似为一个与SST成正比的线性反馈项与一个大气强迫项之和。SHF的反馈参数取决于SST和SHF间的滞后交叉协方差以及SST自协方差。这种反馈总体上为负反馈,减弱SST异常,海表湍流部分起主导作用。最强的反馈可见于南北两半球的中纬度,最大值出现在大洋的西部和中部位置并延伸至高纬度地区。SHF反馈于北半球秋冬两季增强,春夏两季减弱。这些反馈特征在CMIP3耦合气候模式中得到合理的模拟。然而,多数模式中反馈的强度与再分析资料的估值相比略为偏弱。与再分析资料的估值相比,“平均模式”反馈参数比单一模式有更相似的空间形态以及较小的均方根差。基于海表面能量收支平衡,SST的方差可以表示为3个要素的积:1)海表面辐射和湍流通量以及海洋热输送的方差之和;2)一个衡量SST持续性的传输系数G;3)一个反映海表热通量以及海洋热输送之间协方差结构的有效因子e。SST方差的地理分布类似于海表热通量及海洋热输送的方差之和,但为G和e因子所修正。
The exchange of energy at the air-sea interface and ocean advection jointly determine the formation, maintenance and attenuation of sea surface temperature (SST) anomalies. Based on a recent study by the author, this paper reviews the relationship between surface heat flux (SHF) feedback and SST variance and sea surface heat flux and ocean heat transport variance. Sea surface heat flux anomalies can be approximated by the sum of a linear feedback term proportional to SST and an atmospheric forcing term. The feedback parameter of SHF depends on the lag cross covariance between SST and SHF and the SST autocovariance. This feedback is generally negative feedback, weakening SST anomalies, sea surface turbulence part of the leading role. The strongest feedback can be found in the mid-latitudes of the northern and southern hemispheres, with the maximum occurring in the western and central oceans and extending to high latitudes. SHF feedback in the northern hemisphere enhanced autumn and winter, spring and summer weakened. These feedback features are reasonably modeled in the CMIP3 coupled climate model. However, the strength of feedback in most models is slightly weaker than the revaluation data. Compared with the revaluation data, the “average mode” feedback parameter has more similar spatial shape and smaller root-mean-square difference than the single mode. The variance of SST can be expressed as the product of three elements based on the balance of energy expenditure on the sea surface: 1) the sum of the radiative and turbulent fluxes of the sea surface and the variance of ocean heat transport; 2) a transmission coefficient G that measures the SST persistence; 3) An effective factor that reflects the covariance structure between sea surface heat flux and ocean heat transport e. The geographical distribution of SST variance is similar to the sum of the variance of surface heat flux and ocean heat transport but is corrected for G and e factors.