文章基本信息

标题：Sensitivity of forecast errors to initial and lateral boundary conditions
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作者：Nils Gustafsson ; Erland Källén ; Sigurdur Thorsteinsson 等
期刊名称：Tellus A: Dynamic Meteorology and Oceanography
电子版ISSN：1600-0870
出版年度：1998
卷号：50
期号：2
页码：167-185
DOI：10.3402/tellusa.v50i2.14519
摘要：The adjoint of a limited area model has been used to study the sensitivity of 12 h forecast errorsto initial and lateral boundary conditions. Upper troposphere potential vorticity and mean sealevel pressure verification scores for 1 month of operational forecasts from the SwedishMeteorological and Hydrological Institute were used to select 2 cases with particularly poorforecast performance. The sensitivity experiments show that errors in initial data is the mostlikely explanation for one of the forecast failures, while errors in initial as well as lateralboundary data can explain the 2nd forecast failure. Results from the sensitivity experimentswith respect to the lateral boundary conditions indicate that poor quality lateral boundaryconditions may be improved by utilizing subsequent downstream observations within the modelintegration area. This result is of great significance with regard to the possibilities for applying4-dimensional variational data assimilation (4DVAR) for limited area forecast models. Resultsfrom the sensitivity experiments also reveal, however, that the lateral boundary treatment inoperational limited area models needs to be improved with regard to the mathematical formulation.It is furthermore shown that modifications to be applied to the lateral boundary conditionsneed to be determined with appropriate time resolution and that some filtering of these lateralboundary modifications has to be introduced to avoid enhanced high-frequency gravity wavenoise in the vicinity of the lateral boundaries.