Evaluation and Application of the ETA Adjoint Model

9626380霍雷尔，国家科学基金会和国家海洋和大气管理局(NOAA)建立了一个联合计划，以支持共同感兴趣的研究。一般来说，该计划支持的研究涉及有趣的研究工作，满足NOAA的需求，以及那些可以受益于NOAA国家环境预测中心的资源和计算机模型的活动。这项研究将在这一联合计划下得到支持，旨在评估和使用在NOAA NCEP开发的NOAA Eta预报模式及其相关的伴随模式。中尺度Eta模式的不断发展使评估以前没有充分记录的中尺度天气现象成为可能，特别是在美国西部，那里的中尺度大气运动与底层复杂的地形紧密耦合。首席调查员将在目前正在进行的研究的基础上继续发展和扩大，并继续评估中尺度Eta模式在美国西部的表现。NCEP已经开发了Eta模式的伴随项，以使用一种称为四维变分(4DVAR)数据同化的先进数据同化方法。4DVAR同化已在几个个例研究中被证明是导致ETA模式预报的预报技巧改进的结果。随着这一数据同化程序开始在NCEP的常规基础上进行测试，将向模式开发人员以及最终向业务人员提供关于模式预报对初始观测误差和其他因素的敏感性的额外信息。拟议工作的主要目标是参与埃塔伴随模式和相关数据同化方法的开发和应用。具体地说，作为数据同化方法的一部分而获得的初始条件和伴随灵敏度方面的解将作为不同天气形势的函数来评估。***

9626380 Horel The National Science Foundation and the National Oceanic and Atmospheric Administration (NOAA) have established a joint program to support research of mutual interest. Generally, research supported under this program involves activities that are interesting research efforts, address a need of NOAA, and ones that can benefit from the resources and computer models of the NOAA National Center for Environmental Predictions. This research will be supported under this joint program and is aimed at evaluating and using the NOAA Eta forecast model and its associated adjoint model that have been developed at the NOAA NCEP. The ongoing development of the mesoscale Eta model makes it possible to evaluate mesoscale weather phenomena that have not been adequately documented before, especially in the western United States, where mesoscale atmospheric motions are tightly coupled to the underlying complex terrain. The Principal Investigator will build and expand on research underway now and continue to evaluate the performance of the mesoscale Eta modal over the Western United States. The adjoint of the Eta model has been developed at NCEP for using an advanced data assimilation method know as 4-dimensional variational (4DVAR) data assimilation. 4DVAR assimilation has been shown in several case studies to lead to improved forecast skill for Eta model forecasts. As this data assimilation procedure begins to be tested on a routine basis at NCEP, additional information will be available to model developers and, eventually, operational personnel regarding the sensitivity of the model forecasts to initial observational error and other factors. The major goal of the proposed work is to participate in the development and application of the Eta adjoint model and associated data assimilation methods. Specifically, the solutions in terms of both the initial conditions and adjoint sensitivities obtained as part of the data assimilation method will be evalua ted as a function of differing synoptic situations. ***