Characterization of Atmospheric Moisture Transport and the Freshwater Budget of the Arctic with an Improved Regional Model

用改进的区域模型描述北极的大气水分输送和淡水收支

• 批准号: 0138018
• 负责人: Mark Serreze
• 金额: $ 17万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-03-01 至 2007-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0138018&HistoricalAwards=false
• 关键词: Characterization; Atmospheric; Moisture; Transport; Freshwater

0138018SerrezeChanges in the freshwater budget of the Arctic Basin have potentially large impacts on the circulation and sea ice of the Arctic Ocean, which is in turn coupled to the global ocean circulation and climate. However, the atmospheric components of the arctic freshwater budget are characterized relatively poorly and difficult to model. This project will utilize state-of-the-art computational methods to improve climatological simulations of the atmospheric freshwater budget of the Arctic.The salient aspect of high latitude numerical modeling difficulties is the extreme range of scales that must be simulated adequately. Modeling moisture processes requires appropriate treatment of interactions at small spatial scales. By contrast, numerous observational studies have suggested that arctic climate variability is dominated by decadal time scales and planetary spatial scales.These requirements necessitate a trade-off between temporal and spatial scales that cannot be addressed readily with current Eulerian modeling methods, due to computational stability constraints. This study will implement semi-Lagrangian transport for state and dynamical atmospheric variables within the context of a fully coupled atmosphere-ocean-sea ice model. This new implementation would allow both long-term simulations of the fully coupled arctic climate at high resolution, as well as increased use of ensemble techniques for an uncertainty analysis of crucial components of the atmospheric hydrologic cycle. Model experiments will be used to address the following primary research questions:1. What is the sensitivity of the arctic hydrologic cycle to variability in the simulated atmospheric circulation?2. To what extent does the Northern Hemisphere semiannual oscillation influence surface moisture fluxes and/or atmospheric moisture transport? What factors influence interannual variability and trends in the arctic semiannual oscillation?3. What is the influence of anomalous sea ice and/or snow cover on the atmospheric moisture budget over subsequent seasons? Do anomalies in wintertime climate indices translate into anomalous precipitation in other seasons? What summertime or year-round structures in the arctic climate can be identified in atmospheric moisture variables?4. Does atmospheric convection over land play a significant role in the arctic hydrologic cycle during the summer season?

0138018 Serreze北极盆地淡水收支的变化对北冰洋的环流和海冰有潜在的巨大影响，而北冰洋的环流和海冰又与全球海洋环流和气候相耦合。然而，北极淡水收支的大气组成部分的特点相对较差，难以建模。这个项目将利用最先进的计算方法来改进北极大气淡水收支的气候学模拟，高纬度数值模拟困难的突出方面是必须充分模拟的极端尺度范围。模拟水分过程需要在小空间尺度上适当处理相互作用。与此相反，大量的观测研究表明，北极气候变率是由十年的时间尺度和行星的空间尺度，这些要求需要一个时间和空间尺度之间的权衡，不能很容易地解决与目前的欧拉模型方法，由于计算的稳定性限制。这项研究将在一个完全耦合的大气-海洋-海冰模式的范围内对状态和动力大气变量进行半拉格朗日输运。这一新的实施方案将允许以高分辨率对完全耦合的北极气候进行长期模拟，并更多地使用集合技术对大气水文循环的关键组成部分进行不确定性分析。模型实验将用于解决以下主要研究问题：1。北极水文循环对模拟大气环流变化的敏感性是多少？2.北方半年振荡对地面水汽通量和/或大气水汽输送的影响程度如何？什么因素影响北极半年振荡的年际变化和趋势？3.在随后的季节里，异常海冰和/或积雪对大气水分收支的影响是什么？冬季气候指数的异常会转化为其他季节的异常降水吗？在北极气候中，什么样的夏季或全年结构可以在大气湿度变量中识别出来？4.在夏季，陆地上空的大气对流在北极水文循环中是否起着重要的作用？