Cold Microphysical Effects on Surface Rainfall Variability in the Tropics

冷微物理对热带地表降雨变化的影响

• 批准号: 0125706
• 负责人: Konstantine Georgakakos
• 金额: $ 18万
• 依托单位: Hydrologic Research Center
• 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: 2002-05-01 至 2004-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0125706&HistoricalAwards=false
• 关键词: Cold; Microphysical; Effects; Surface; Rainfall

0125706GeorgakakosThe focus of the two-year research project is to quantify the relativeimportance of (a) the large-scale forcing fields of water vapor andthermal buoyancy versus (b) the storm microphysics for the developmentof the spatio-temporal characteristics of convective oceanic surfacerainfall variability. Of particular interest is to understand theeffects of cold microphysical properties on rainfall variability atvarious spatiotemporal domains and resolutions. The research studiesoceanic rainfall as a first step toward the understanding of the causesof rainfall variability by separating the large scale forcing andmicrophysics from the complex terrain influences present in continentalrainfall. The research results are of fundamental importance forhydrometeorology and hydrology, and they may be used in applicationssuch as (a) downscaling or upscaling rainfall estimates obtained byremote sensing or by large-scale climate models, or (b) hydrologicdesign studies requiring rainfall estimates of high spatio-temporalresolution. Statistical-dynamical numerical models of rainfall genesisand evolution are combined with data from national large-scaleexperiments to achieve the goals of the project. State equations forthe vertical momentum, mass and energy conservation are integratedefficiently using typical vertical profiles of the state variables,estimated from field experiments in convective regimes. A number ofquantitative hypothesis are tested regarding the causes of rainfallvariability in domains of a 256-km length, with spatial resolution of 1km and temporal resolution of 1 min. The models are used in aMonte-Carlo framework that incorporates uncertainties in observed data,large-scale forcing fields, and model microphysical parameterizations,including possible feedbacks from the generated cloud to the near fieldlarge-scale forcing.

0125706Georgakakos 这个为期两年的研究项目的重点是量化（a）水蒸气和热浮力的大规模强迫场与（b）风暴微物理对于发展对流海洋表面降雨变化的时空特征的相对重要性。 特别令人感兴趣的是了解冷微物理特性对不同时空域和分辨率下降雨变化的影响。 该研究通过将大尺度强迫和微物理与大陆降雨中存在的复杂地形影响分开，研究海洋降雨，作为了解降雨变化原因的第一步。 研究成果对于水文气象学和水文学具有根本重要性，可用于以下应用：（a）通过遥感或大尺度气候模型获得的降尺度或升尺度降雨估计，或（b）需要高空间降雨估计的水文设计研究。 -时间分辨率。 降雨发生和演变的统计动力数值模型与国家大型实验数据相结合，以实现该项目的目标。 使用状态变量的典型垂直剖面，对垂直动量、质量和能量守恒的状态方程进行有效积分，这些状态变量是根据对流区域的现场实验估计的。 在 256 公里长度、空间分辨率为 1 公里、时间分辨率为 1 分钟的区域内，对一些关于降雨变化原因的定量假设进行了检验。 该模型采用蒙特卡罗框架，该框架结合了观测数据、大规模强迫场和模型微物理参数化的不确定性，包括从生成的云到近场大规模强迫的可能反馈。