Horizontal structure of hemispheric forecast error correlations for geopotential and temperature
Horizontal structure of hemispheric forecast error correlations for geopotential and temperature
复制标题
位势和温度半球预报误差相关性的水平结构
DOI：
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发表时间：
1986
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通讯作者：
Donald W. Shantz
中科院分区：
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作者：
H. J. Thiébaux;Herschel L. Mitchell;Donald W. Shantz
摘要对加拿大大尺度预报模式的半球预报误差统计进行了详细研究，为预报周期数据同化步骤中相关函数的再参数化做准备。为位势高度和温度选择适当的函数类型（即滞后相关表示）是一个主要问题。考虑了许多可能的函数表示，包括各向同性和各向异性，并比较了从观察到的f.e.数据计算的各种候选函数的相关性的拟合优度。选取二阶自回归函数的特殊形式为：（1 + c|s|）e−c|s|，其中|s|为地理位置分离。在区域基础上对fe相关结构的检查揭示了区域之间的巨大差异。恒压统计结构的纬度、压力水平和季节依赖关系。
Abstract A detailed study of hemispheric forecast-error (f.e.) statistics for the operational Canadian large-scale forecast model was made in preparation for reparameterization of the correlation function used in the data assimilation step of the forecast cycle. The choice of an appropriate function type for geopotential height and temperature f.e. lag-correlation representations was a major concern. A number of possible functional representations, both isotropic and anisotropic, were considered, and the goodness-of-fit of the various candidate functions to correlations computed from observed f.e. data were compared. The following special form of the second-order autoregressive function was adopted as the function of choice: (1 + c|s|)e−c|s|, where |s| is geographic location separation. An examination of f.e. correlation structure on a regional basis revealed large differences from region to region. Latitudinal, pressure-level, and seasonal dependencies of the statistical structure of constant pressure-su...