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

本研究基于阿根廷南部敏捷流星雷达(SAMER)的观测，该雷达于2008年5月安装在火地岛(53.8 oS)的里奥格兰德岛。自安装以来，萨默尔进行了中层大气大尺度动力学的常规测量，确定了小尺度重力波(GWS)造成的月平均动量通量，并在常规测量模式下表征了流星头回波和非镜面流星轨迹。以前，常规的GW动量通量测量只能用大型(和昂贵的)雷达进行，而流星头回波和非镜面痕迹研究只能用同样大、非常昂贵且只能断断续续地用于此类研究的“高功率、大口径”(HPLA)雷达。当被用于垂直观察不同发射机相位的实验研究时，Saamer有望对流星体头部回波、非镜面轨迹和轨道研究以及极地中层夏季回波(PMSE)和相关微物理研究做出重大贡献。Saamer安装在火地岛(TdF)上，以提供对大范围动力学，特别是半日潮的敏感性，该纬度带预计将显示较大的半日潮幅度，但没有其他仪器。它在TdF上的位置也是因为地球上以南安第斯山脉、德雷克海峡和南极半岛为中心的GW活动的主要“热点”的发生。这一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GWS和动量通量，并与中间层和低热层(MLT)的大尺度运动场发生强烈相互作用，到目前为止，Saamer的分析证实了这一区域的通量可能非常大的预期。这项研究涉及当前高度感兴趣并与不同社区相关的主题。MLT动力学研究，特别是GW动力学、动量输送及其沉积的量化，是在大气环流、数值天气预报、气候和空间天气模拟中定义这些小尺度动力学的更准确参数的核心需要。对大尺度动力学的测量同样用于约束缺少关键输入的这些动力学模型，特别是在南部高纬度地区。流星轨迹研究可能会为潜在的流星撞击风险提供线索。Saamer还被用作教育和培训工具，通过各种NSF项目致力于促进美国和美国研究人员和学生之间的国际合作活动，包括迄今为止美国、阿根廷和巴西之间的广泛交流，并由此产生了积极的合作。

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.