Collaborative Research: Expanded Correlative Dynamics and Meteor Studies Using the Southern Argentina Agile MEteor Radar

合作研究：使用阿根廷南部敏捷流星雷达扩展相关动力学和流星研究

• 批准号: 1647506
• 负责人: Steven Smith
• 金额: $ 7.51万
• 依托单位: Trustees of Boston University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1647506&HistoricalAwards=false
• 关键词: Collaborative; Research; Expanded; Correlative; Dynamics

The research for this award would renew the support for the ongoing operations of the Southern Argentina Agile MEteor Radar (SAAMER) system but with diverse and significantly expanded research applications using data from two new correlative instruments to be installed by research colleagues from two other institutions (Boston University and Institute for Atmospheric Physics, Germany). SAAMER was installed on Tierra del Fuego (TdF) to observe the large-scale dynamics within the mesosphere and lower thermosphere (MLT) in the altitude range of 75 to 95 km. This height range is where the semidiurnal tide and various planetary waves have a range of diverse effects. This location is within a latitude band where these motions have large responses, but also where the existing MLT database of winds and temperatures is quite sparse. The SAAMER location on TdF was also motivated by the occurrence of the major 'hotspot' of gravity wave (GW) activity on Earth centered over the Southern Andes, Drake Passage, and Antarctic Peninsula. This hotspot is due to the major GW sources in this region, which include high mountains, strong jet streams, and the passage of vigorous frontal systems. These sources yield large GW events and significant MLT momentum fluxes (MF). Strong interactions of GW structures with the larger-scale motions in the MLT region are to be expected, and SAAMER results to date confirm expectations that the fluxes in this region would be very large. This work has also revealed an ability to characterize meteor head echoes, non-specular meteor trails, and meteor radiants observed in routine measurement modes. The new SAAMER studies would be more comprehensive than before due to correlative airglow imaging as well as new local Rayleigh lidar and multi-receiver radar measurements combined with the use of satellite observations by SABER on TIMED and CIPS on AIM for large- and small-scale dynamics studies. These multi-instrument studies will enable quantification of the important small-scale GWs (and MFs) having wavelengths ëh~20-100 km that are challenging to quantify without such correlative measurements. MLT dynamical studies, especially in regard to the quantification of GW dynamics, momentum transport and its deposition, are central needs in defining more accurate parameterizations of these dynamics in global research, weather prediction, and climate models addressing broad societal needs. Measurements of large-scale dynamics likewise serve to constrain models of these dynamics, especially at high southern latitudes. Meteoroid trajectory studies may provide clues to potential meteor impact risks. SAAMER is also 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.The research award to the PI would address MLT dynamics, meteors, and microphysics with focus upon the following questions:1) Continued Large-scale dynamics studies of mean winds, tides, and PWs and their structure, interactions, and inter-hemispheric and inter-annual variability;2) Further quantification of momentum fluxes by small-scale GWs employing SAAMER, the BU all-sky imager, and the IAP Rayleigh lidar, with exploration of GW sources and their propagation characteristics combined with the study of possible development of secondary GW generation, and influences by mean winds, tides, and PWs;3) Further characterization of the meteoroid population, velocities, trajectories, diurnal, seasonal, and global variability of meteor rates, and the meteoric mass flux into the MLT; and4) Routine measurements of meteor head echoes and non-specular trails and PMSE allowing studies addressing meteor ablation and PMSE microphysics.

这一奖项的研究将继续支持阿根廷南部Agile流星雷达(SAAMER)系统目前的运作，但将利用另外两个机构(波士顿大学和德国大气物理研究所)的研究同事将安装的两个新的相关仪器的数据，进行各种和显著扩大的研究应用。SAAMER安装在火地岛(TDF)上，用于观测75-95公里高度范围内中间层和低热层(MLT)内的大尺度动力学。这个高度范围是半日潮和各种行星波产生一系列不同影响的地方。这个位置在纬度范围内，在那里这些运动有很大的响应，但现有的MLT风和温度数据库也相当稀少。TdF上的Saamer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重力波(GW)活动的主要“热点”的发生。这一热点是由于该地区的主要GW源，包括高山、强急流和活跃的锋面系统的通道。这些源产生了大的GW事件和显著的MLT动量通量(Mf)。GW结构与MLT区域较大尺度运动的强相互作用是可以预期的，到目前为止，Saamer的结果证实了该区域通量将非常大的预期。这项工作还揭示了在常规测量模式下观察到的流星头回声、非镜面流星轨迹和流星辐射的特征。由于相关的气辉成像以及新的本地瑞利激光雷达和多接收器雷达测量，新的SAAMER研究将比以前更全面，并利用SABER在TIMED上和CIPS在AIM上进行的卫星观测进行大小规模的动力学研究。这些多仪器研究将能够对波长为20-100千米的重要小规模GWS(和MFS)进行量化，如果没有这种相关测量，就很难量化这些GWS(和MFS)。MLT动力学研究，特别是关于GW动力学、动量输送及其沉积的量化，是在全球研究、天气预报和气候模型中更准确地定义这些动力学参数以满足广泛社会需求的核心需求。对大尺度动力学的测量同样用于约束这些动力学的模型，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。SAMER也是一个教育和培训工具，通过各种NSF项目致力于促进美国和美国与美国研究人员和学生之间的国际合作活动，包括美国、阿根廷和巴西之间迄今的广泛交流。PI的研究奖将涉及MLT动力学、流星和微物理，重点关注以下问题：1)持续的平均风、潮汐和PWS及其结构、相互作用、半球间和年际变化的大规模动力学研究；2)通过使用Saamer、BU全天成像仪和IAP Rayleigh激光雷达的小尺度GWS进一步量化动量通量，探索GW源及其传播特征，结合研究二次GW产生的可能发展，以及平均风、潮汐和PWS的影响；3)进一步描述流星体的数量、速度、轨迹、日变化、季节变化和全球变率，以及进入MLT的大气质量通量；以及4)常规测量流星头回波和非镜面尾迹和PMSE，以便进行流星烧蚀和PMSE微物理研究。