Forecast Sensitivity to Regional and Global Targeting of the Initial State

小行星9714291 美国天气研究计划（USWRP）是一项跨部门活动，旨在执行和实施必要的研究，以改善向国家提供的天气服务。 根据这一方案，国家科学基金会、国家海洋和大气管理局、国家航空航天局和海军研究办公室正在联合评估和支持美国水资源研究计划高度优先的研究。 在这项研究中，主要研究者将调查区域和全球范围的初始不确定性对模型预测灵敏度的相对贡献。 最近的几项研究强调当地有针对性的观测的好处，根据估计的不确定性增长产生的伴随，“繁殖模式”，和奇异向量分析。 这种方法识别动态不稳定区域，在该区域内，局部初始状态的细节可能与随后的预报演变特别相关。 目前尚不清楚这些方法是否区分预测的敏感性，因为全球规模的背景流的规格略有不确定性。 对1996年3月12日至14日的“超级风暴”的样本预报表明，包括导致风暴的初始位涡最大值在内的上游域的细节对于96小时预报是重要的。 这些发现激发了拟议的工作，该工作将估计 规范的大气状态，并将量化的不确定性对数值天气预报的影响作为不确定性的位置和规模的函数。 这项研究的工作假设是，通过数值方法进行的局部天气预报往往更敏感地依赖于初始全球尺度状态的相对较小的不确定性，而不是初始区域状态的不确定性。 将比较三种不同的全球再分析产品。 不同的，同样可信的大气分析的差异提供了一个衡量目前的不确定性在初始状态，并将光谱量化。 由此估计的不确定性将被插入到一个全球可变分辨率模式的初始状态，以确定随后的预测灵敏度的尺度依赖性。 敏感性研究将侧重于从春季和冬季条件中选择的一些初始状态。 最初的目标领域还将包括太平洋数据空白。 这项研究的成功完成可能会有重要的影响，业务预测的数据收集策略。 ***

9714291 Paegle The U.S. Weather Research Program (USWRP) is an interagency activity designed to perform and implement the research necessary to improve the delivery of weather services to the nation. Under this Program, the National Science Foundation, the National Oceanic and Atmospheric Administration, the National Aeronautics and Space Administration and the Office of Naval Research are jointly evaluating and supporting research of high priority to the USWRP. In this research, the Principal Investigator will investigate the relative contributions of regional and global-scale initial uncertainties on model forecasting sensitivity. Several recent studies emphasize benefits of locally targeted observations, based upon estimates of uncertainty growth produced by adjoint, "bred mode", and singular vector analyses. Such methods identify dynamically unstable regions within which details of the local initial state may have special relevance for subsequent forecast evolution. It is unclear whether those approaches distinguish forecast sensitivities due to slightly uncertain specification of the global-scale, background flow. Sample forecasts of the "superstorm" of 12-14 March 1996 suggest that details of the upstream domain that includes the initial potential vorticity maxima leading to the storm are important for a 96 h forecast. Such findings motivate the proposed work which will estimate uncertainty in specification of the atmospheric state, and will quantify impact of the uncertainty upon numerical weather prediction as a function of uncertainty location and scale. The working hypothesis of the research is that local weather prediction by numerical methods often depends more sensitively on relatively small uncertainties of the initial global-scale state than upon uncertainties of the initial regional state. Three separate global reanalysis products will be compared. The differences of different, equally credible atmospheric analyses prov ide a measure of current uncertainty in the initial state, and will be spectrally quantified. The uncertainties thus estimated will be inserted into the initial states of a global variable resolution model to determine the scale dependence of subsequent forecast sensitivity. Sensitivity studies will focus on a number of initial states selected from Spring and Winter conditions. Initially targeted domains will also include the Pacific data void. Successful completion of this research potentially will have important implications for data collection strategies for operational forecasting. ***