Assessment of gravity wave momentum flux measurement capabilities by meteor radars having different transmitter power and antenna configurations
Assessment of gravity wave momentum flux measurement capabilities by meteor radars having different transmitter power and antenna configurations
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DOI：
10.1029/2011jd017174
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发表时间：
2012-05
影响因子：
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通讯作者：
D. Fritts;D. Janches;W. Hocking;N. Mitchell;M. Taylor
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文献类型：
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作者：
D. Fritts;D. Janches;W. Hocking;N. Mitchell;M. Taylor
[1]评估和比较了五个流星雷达的测量能力，以确定具有不同发射功率和天线配置的雷达在确定平均风、潮汐幅度和重力波(GW)动量通量方面的表现。这五个雷达包括阿根廷火地岛(53.8°S)和南极乔治王岛(62.1°S)上的两个新一代流星雷达，以及新墨西哥州索科罗(34.1°N，106.9°W)、犹他州熊湖天文台(∼41.9N，111.4°W)和加拿大耶洛奈夫(62.5°N，114.3°W)的常规流星雷达。我们的评估使用了每个雷达在2009年6月、2010年6月或2011年6月观测到的流星分布和一组七个测试运动场，包括平均风、恒定日潮汐、恒定和可变半日潮的各种叠加，以及具有不同幅度、尺度、周期、传播方向、动量通量和间歇的叠加GW。雷达具有更高的功率和/或天线方向图，在小天顶角产生更多的流星计数，在定义月和日平均风速、潮汐幅度和GW动量通量方面表现良好，尽管预计每日估计的不确定性更大。传统雷达功率较低，只有一个发射天线，能够相当好地描述月平均风速和潮汐幅度，特别是在流星数量最高的高度。它们还对流星数量最多的高度的GW动量通量提供了合理的估计；然而，这些估计受到∼20%至50%的不确定性的影响，并且不确定性在较高和较低的高度迅速变得过大。对于更复杂的运动场，所有量的估计值都会有所下降。
[1] Measurement capabilities of five meteor radars are assessed and compared to determine how well radars having different transmitted power and antenna configurations perform in defining mean winds, tidal amplitudes, and gravity wave (GW) momentum fluxes. The five radars include two new-generation meteor radars on Tierra del Fuego, Argentina (53.8°S) and on King George Island in the Antarctic (62.1°S) and conventional meteor radars at Socorro, New Mexico (34.1°N, 106.9°W), Bear Lake Observatory, Utah (∼41.9°N, 111.4°W), and Yellowknife, Canada (62.5°N, 114.3°W). Our assessment employs observed meteor distributions for June of 2009, 2010, or 2011 for each radar and a set of seven test motion fields including various superpositions of mean winds, constant diurnal tides, constant and variable semidiurnal tides, and superposed GWs having various amplitudes, scales, periods, directions of propagation, momentum fluxes, and intermittencies. Radars having higher power and/or antenna patterns yielding higher meteor counts at small zenith angles perform well in defining monthly and daily mean winds, tidal amplitudes, and GW momentum fluxes, though with expected larger uncertainties in the daily estimates. Conventional radars having lower power and a single transmitting antenna are able to describe monthly mean winds and tidal amplitudes reasonably well, especially at altitudes having the highest meteor counts. They also provide reasonable estimates of GW momentum fluxes at the altitudes having the highest meteor counts; however, these estimates are subject to uncertainties of ∼20 to 50% and uncertainties rapidly become excessive at higher and lower altitudes. Estimates of all quantities degrade somewhat for more complex motion fields.