Influence of Land Use and Landscape Heterogeneity on Cloud Formation and Atmospheric Circulation in Southwest Australia

澳大利亚西南部土地利用和景观异质性对云形成和大气环流的影响

• 批准号: 0523583
• 负责人: Udaysankar Nair
• 金额: $ 53.24万
• 依托单位: University of Alabama in Huntsville
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-11-01 至 2009-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0523583&HistoricalAwards=false
• 关键词: Influence; Land; Use; Landscape; Heterogeneity

Southwest Australia is an ideal test bed to investigate the influence of land use on cloud formation and atmospheric circulation patterns. Clearing of native vegetation for agricultural purposes has resulted in a 700 km long sharp boundary between the croplands and the undisturbed vegetation areas. Preliminary studies suggest that replacement of native vegetation by agricultural crops alters the surface energetics, directly influencing convective cloud formation. The drastic nature and large spatial extent of the land surface heterogeneity is conducive to the formation of secondary circulations that also impact cloud formation. This investigation will address a series of scientific questions related to the hypothesized impact on land use on cloud formation and regional atmospheric circulations of southwest Australia using a combination of ground, satellite, aircraft observations, spatial statistical analysis and numerical modeling experiments. This study will utilize these observations to characterize surface energetics and atmospheric thermodynamic structure as a function of land use and its relationship to cloud formation. Observations will also be used to verify the existence of secondary mesoscale circulations generated by landscape heterogeneity. Numerical simulations, in combination with observations, will be used to determine if differences in land use are responsible for observed variations in cloud formation and if mesoscale circulations are forced by landscape heterogeneity. Detailed analysis of satellite observed cloudiness will be conducted to determine the statistical significance of differences in cloud formation over the croplands and native vegetation This study is unique in the sense that the landscape heterogeneity has significantly higher spatial scales and exhibits drastic spatial changes. The scale and nature of the spatial heterogeneity is important since prior studies have been criticized for employing hypothetical landscape heterogeneity patterns with large spatial scales and drastic changes that have no counterparts in nature. One of the broader impacts of this study is expected to be its potential contribution towards resolving the ongoing debate on the impact of landscape heterogeneity on regional climate. The results from this study are also expected to be of utility to land use management planners experiencing drastic land use change. This research effort will enable international collaboration between researchers in United States, Australia and Japan and promote graduate education through the participation of graduate students in both the field campaign and the analysis of data generated during the project.

澳大利亚西南部是研究土地利用对云形成和大气环流模式影响的理想试验台。 为农业目的清除原生植被，在农田和未受干扰的植被区之间形成了700公里长的明显边界。 初步研究表明，农作物取代原生植被改变了地表能量，直接影响对流云的形成。 陆面非均匀性的剧烈性质和大的空间范围有利于二次环流的形成，也影响云的形成。这项调查将解决一系列的科学问题有关的假设影响土地利用云的形成和区域大气环流的澳大利亚西南部使用地面，卫星，飞机观测，空间统计分析和数值模拟实验相结合。 这项研究将利用这些观测来表征地面能量学和大气热力学结构作为土地利用的函数及其与云形成的关系。 观测还将用于验证景观异质性产生的次级中尺度环流的存在。 数值模拟与观测相结合，将用于确定土地利用的差异是否是观测到的云形成变化的原因，以及中尺度环流是否是由景观异质性造成的。 详细分析卫星观测的云量，以确定云的形成在农田和原生植被的差异的统计意义。这项研究是独特的，在这个意义上说，景观异质性具有显着较高的空间尺度，并表现出剧烈的空间变化。 的空间异质性的规模和性质是重要的，因为以前的研究一直批评采用假设的景观异质性模式与大的空间尺度和剧烈的变化，没有对应的性质。这项研究的更广泛的影响之一，预计将是其对解决正在进行的辩论景观异质性对区域气候的影响的潜在贡献。 本研究之研究结果，亦可望提供土地利用管理规划者面对土地利用剧烈变化时之参考。 这项研究工作将使美国、澳大利亚和日本的研究人员能够开展国际合作，并通过研究生参与实地活动和分析项目期间产生的数据来促进研究生教育。