Large- and Small-Scale Dynamics and Comprehensive Meteor Studies with the Southern Argentina Agile MEteor Radar (SAAMER)

使用阿根廷南部敏捷流星雷达 (SAAMER) 进行大尺度和小尺度动力学以及综合流星研究

• 批准号: 1112830
• 负责人: David Fritts
• 金额: $ 45万
• 依托单位: GLOBAL ATMOSPHERIC TECHNOLOGIES AND SCIENCES, INC.
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1112830&HistoricalAwards=false
• 关键词: Large; Small; Scale; Dynamics; Comprehensive

This study is based on observations made by the Southern Argentina Agile MEteor Radar (SAAMER), which was installed at Rio Grande on Tierra del Fuego (53.8oS) in May 2008. Since its installation, SAAMER has performed routine measurements of large-scale dynamics of the middle atmosphere, determined the monthly-mean momentum fluxes due to smaller-scale gravity waves (GWs), and characterized meteor head echoes and non-specular meteor trails in a routine measurement mode. Previously, routine GW momentum flux measurements were only possible with large (and expensive) radars, while meteor head echo and non-specular trail studies were only possible with "high-power, large-aperture" (HPLA) radars that are likewise large, very expensive, and used only intermittently for such studies. When employed for experimental studies viewing vertically with different transmitter phasing, SAAMER promises to contribute significantly to meteoroid head echo, non-specular trail, and trajectory studies, as well as to Polar Mesospheric Summer Echoes (PMSE) and related microphysics studies. SAAMER was installed on Tierra del Fuego (TdF) to provide sensitivity to the large-scale dynamics, especially the semidiurnal tide, in a latitude band expected to exhibit large semidiurnal tide amplitudes, but devoid of other instrumentation. Its location on TdF was also motivated by the occurrence of the major "hotspot" of GW activity on Earth centered over the Southern Andes, Drake Passage, and Antarctic Peninsula. This hotspot is due, apparently, to the major GW sources in this region, believed to include high mountains, strong jet streams, and vigorous frontal systems. These sources are expected to yield large GWs and momentum fluxes and strong interactions with the large-scale motion field in the mesosphere and lower thermosphere (MLT), and SAAMER analyses to date confirm expectations that the fluxes in this region can be very large. This research addresses topics that are of high current interest and relevant to diverse communities. MLT dynamics studies, especially quantification of GW dynamics, momentum transport, and its deposition, are central needs in defining more accurate parameterizations of these small-scale dynamics in general circulation, numerical weather prediction, climate, and space weather modeling. Measurements of large-scale dynamics likewise serve to constrain models of these dynamics that are missing key inputs, especially at high southern latitudes. Meteoroid trajectory studies may provide clues to potential meteor impact risks. SAAMER is also utilized as an educational and training tool through various NSF programs devoted to promoting international collaborative activities between U.S. and S. American researchers and students, including extensive exchanges between the U.S., Argentina, and Brazil to date, with active collaborations arising from these.

这项研究是基于阿根廷南部敏捷METEOR雷达（SAAMER），这是安装在格兰德河火地岛（53.8南纬）在2008年5月的观测。自安装以来，SAAMER对中层大气的大尺度动态进行了常规测量，确定了由于小尺度重力波（GW）引起的月平均动量通量，并以常规测量模式描述了流星头回波和非镜面流星尾迹的特征。以前，常规的GW动量通量测量只能使用大型（和昂贵的）雷达，而流星头回波和非镜面尾迹研究只能使用“高功率，大孔径”（HPLA）雷达，这些雷达也很大，非常昂贵，并且只能间歇地用于此类研究。当采用不同的发射机相位垂直观看实验研究时，SAAMER有望为流星体头部回波、非镜面尾迹和轨迹研究以及极地中间层夏季回波（PMSE）和相关微物理研究做出重大贡献。SAAMER安装在火地岛（TdF）上，以提供对大尺度动力学的灵敏度，特别是在一个纬度带的半日潮，预计将表现出大的半日潮振幅，但没有其他仪器。它在TdF上的位置也是由于地球上GW活动的主要“热点”的出现，该热点集中在南安第斯山脉、德雷克海峡和南极半岛。这个热点显然是由于该地区的主要GW来源，据信包括高山，强烈的急流和活跃的锋面系统。预计这些源将产生大的全球Ws和动量通量，并与中间层和低热层（MLT）的大尺度运动场产生强烈的相互作用，迄今为止的SAAMER分析证实了这一区域的通量可能非常大的预期。这项研究涉及的主题是当前高度关注和相关的不同社区。MLT动力学研究，特别是GW动力学，动量传输及其沉积的量化，是定义更准确的参数化这些小尺度动力学在大气环流，数值天气预报，气候和空间天气建模的核心需求。对大规模动态的测量同样有助于限制缺少关键输入的这些动态模型，特别是在南半球高纬度地区。流星体轨迹研究可为潜在的流星撞击风险提供线索。SAAMER也被利用作为教育和培训工具，通过各种致力于促进美国和美国之间的国际合作活动的NSF计划。美国研究人员和学生，包括美国之间的广泛交流，迄今为止，阿根廷和巴西与这些国家进行了积极的合作。