估值类数据同化方法中背景场的确定——三维可分离的情况

Preparation for the background of the estimating data assimilation method——the separated background branch

以相关性为基础,详细研究了估值类数据同化方法中背景场的确定问题,并以渤海3月份到7月份的温度场为例,具体说明了如何确定背景场:当要素场在水平方向和垂直方向上可以进行分离变量时,背景场的确定可以通过单独确立水平相关性与垂直相关性完成。研究表明:(1)当没有温跃层时,温度在垂向上的相关是沿着整个深度的;(2)当有温跃层时,温度在垂向上的相关应该限定在上准等温层的下界;(3)在温度的垂向分布方面,其相关性与温跃层有着对应关系,对比相关性与温跃层可以看出,垂向相关性与温跃层位置的变化趋势一致。

Based on the relativity, the preparation for the background of the estimating data assimilation method is studied. The Bohai temperature, as an example cited in this paper from March to July, is detailed to prepare the background when its horizontal distribution and vertical one can be separated from each other. The research reaches the conclusions that the covariances of horizontal and vertical ones can be constructed respectively when such separation can be done; that the relative coefficient along vertical direction strides the total depth where there no thermocline; that the relative coefficient along vertical direction is limited strictly above and below the thermocline where there one exists; and that thethermocline can be regarded as a barrier layer; that the trend of the relative coefficient is akin to that of the temperature along the vertical direction.