Dynamic Reassimilation of Atmospheric Observations for Global Climate Change Studies: A Feasibility Study

全球气候变化研究的大气观测动态重同化：可行性研究

• 批准号: 9344212
• 负责人: Jagadish Shukla
• 金额: --
• 依托单位: Institute of Global Environment and Society
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-06-01 至 1994-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9344212&HistoricalAwards=false
• 关键词: Dynamic; Reassimilation; Atmospheric; Observations; Global

The PIs will produce a four-dimensional internally consistent gridded data set for the global atmosphere for the period May 1982 to November 1983. They will do so by assembling the most complete set of atmospheric and oceanic observations made during that period and by using a state-of-the-art multivariate optimal interpolation scheme for atmospheric data assimilation. The primary motivation or this work is to demonstrate the feasibility of reanalyzing past atmospheric observations using a state-of-the-art global model and a global data assimilation system. Such a feasibility study is needed before making plans for reanalysis of long term ( 10 years) historical data sets for climate research. The data assimilation system to be used will include the COLA general circulation model, the forecast of which will provide the first guess, and most accurate optimum interpolation gorithm available. The observational data se will be a combination for level II-data archived in real time during the period and delayed mode data, including the comprehensive Ocean-Atmosphere Data Set (COADS), which have been assembled at NCAR. The critical evaluations of the analyses will include general circulation statistics; global and local energy spectra; global energetic diagnoses including generation and dissipation of energy; a detailed examination of the global hydrologic cycle including regional budgets for the tropical Pacific, North America, the Amazon basin, and sub-Saharan Africa; and computations of surface wind stress and total heat flux to force a global ocean model. The PIs will archive the various measures of analysis error obtained during the assimilation cycle to study the quality of the analyses and to provide confidence estimates and error bars. This study will be extremely useful to support the scientific objectives of national and international research programs such as the Tropical Oceans Global Atmospheric (TOGA), World Ocean Circulation Experiment (WOCE), Global Energy and Water Cycle Experiment (GEWEX) and International Geosphere Biosphere Program (IGBP). The PIs have chosen the 1982--83 period for this study because it witnessed the most outstanding example of ocean- atmosphere interactions as manifested by the El Nino-Southern Oscillation phenomenon and its related world-wide effects.

PI将产生1982年5月至1983年11月期间全球大气的四维内部一致网格数据集。为此，他们将汇集这一期间最完整的一套大气和海洋观测数据，并使用最先进的多元最佳插值方案进行大气数据同化。这项工作的主要动机是证明使用最先进的全球模式和全球数据同化系统重新分析过去的大气观测的可行性。在为气候研究重新分析长期（10年）历史数据集制定计划之前，需要进行这种可行性研究。将使用的数据同化系统将包括COLA大气环流模式，该模式的预报将提供初步猜测和现有的最准确的最佳插值。观测数据se将是这一期间以真实的时间存档的二级数据和延迟模式数据的组合，其中包括已在国家大气研究中心汇编的综合海洋-大气数据集。对分析的关键评价将包括：大气环流统计;全球和地方能量谱;全球能量诊断，包括能量的产生和耗散;详细审查全球水文循环，包括热带太平洋、北美、亚马逊盆地和撒哈拉以南非洲的区域预算;计算表面风应力和总热通量，以建立全球海洋模型。PI将对同化周期中获得的分析误差的各种测量进行存档，以研究分析的质量，并提供置信度估计值和误差条。这项研究将非常有助于支持国家和国际研究方案的科学目标，如热带海洋全球大气（TOGA），世界海洋环流实验（WOCE），全球能源和水循环实验（GEWEX）和国际地圈生物圈计划（IGBP）。研究所选择一九八二至八三年为研究期，是因为这段期间是海洋与大气相互作用最显著的时期，例如厄尔尼诺-南方涛动现象及其相关的全球影响。