The Impact of Spatial and Temporal Variability of the Landscape on Atmosphere-Land Surface Interactions at the Mesoscale

地貌时空变化对中尺度大气-地表相互作用的影响

• 批准号: 9415441
• 负责人: Roni Avissar
• 金额: $ 14万
• 依托单位: Rutgers University New Brunswick
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-04-15 至 1998-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9415441&HistoricalAwards=false
• 关键词: Impact; Spatial; Temporal; Variability; Landscape

9415441 Avissar As part of a prior NSF investigation (EAR-9105059), it was demonstrated that subgrid-scale heat and momentum fluxes associated with mesoscale circulations generated by horizontal gradients of water availability for evapotranspiration, have a significant impact on the atmospheric processes simulated with large-scale atmospheric numerical models (e.g., GCMs). However, these fluxes, which can be three times stronger than turbulent (i.e., microscale) fluxes, are not represented in such models. The research proposed here is a continuation of this prior investigation, which concentrates on clouds and precipitation generated by landscape discontinuities at the mesoscale and their interactions with the horizontal distribution of soil moisture, evapotranspiration, and the other surface fluxes. The proposed research includes three major tasks, which are expected to be accomplished within three years (one task a year): (i) a sensitivity analysis of which parameters are most important in the parameterization of cloud and precipitation microphysics relevant to land-atmosphere interactions; (ii) a systematic analysis of the impact of water availability for evapotranspiration at the ground surface on clouds and precipitation; and (iii) a parameterization of mesocale heart fluxes (including moist processes) generated by land-surface heterogeneity for large-scale atmospheric models. To perform efficiently this research, which is based on numerical analysis, it is very important to adopt a models that has refined parameterizations of cloud physics as well as land hydrology. Furthermore, it should have the flexibility to produce simulations on a broad range of spatial scales. Thus, the Colorado State University (CSU) Regional Atmospheric Modeling System (RAMS), a state-of-the-art modeling system designed to support basic research in the atmospheric sciences will be used for this investigation. This research, which will provide new insights in the complex hydrometeorological processes in volved in land-atmosphere interactions at the mesoscale, is expected to be particularly relevant and beneficial for the research activity endorsed by GEWEX and other national and international programs.

9415441 Avissar 作为先前 NSF 调查 (EAR-9105059) 的一部分，结果表明，与蒸散水可用性水平梯度产生的中尺度环流相关的次网格尺度热和动量通量，对模拟的大气过程有重大影响大型大气数值模型（例如 GCM）。 然而，这些通量可能比湍流（即微尺度）通量强三倍，但在此类模型中并未得到体现。 这里提出的研究是先前研究的延续，该研究集中于中尺度景观不连续性产生的云和降水及其与土壤湿度、蒸散量和其他表面通量的水平分布的相互作用。 拟议的研究包括三项主要任务，预计将在三年内完成（一年一项任务）：（i）对与陆地-大气相互作用相关的云和降水微物理参数化中哪些参数最重要进行敏感性分析; ㈡ 系统分析地表蒸散的可用水量对云和降水的影响； (iii) 由大尺度大气模型的地表异质性产生的中尺度中心通量（包括潮湿过程）的参数化。 为了有效地进行这项基于数值分析的研究，采用对云物理和陆地水文学进行精细参数化的模型非常重要。 此外，它应该具有在广泛的空间尺度上进行模拟的灵活性。 因此，科罗拉多州立大学（CSU）区域大气模拟系统（RAMS）是一个旨在支持大气科学基础研究的最先进的模拟系统，将用于这项调查。 这项研究将为涉及中尺度陆地-大气相互作用的复杂水文气象过程提供新的见解，预计对 GEWEX 和其他国家和国际项目认可的研究活动特别相关和有益。