Wind velocity and temperature fluctuations due to a 2‐day wave observed with radio meteor echoes
Wind velocity and temperature fluctuations due to a 2‐day wave observed with radio meteor echoes
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射电流星回波观测到的 2 天波引起的风速和温度波动
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
S. Fukao
中科院分区：
文献类型：
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作者：
M. Tsutsumi;T. Tsuda;Takuji Nakamura;S. Fukao
本文利用日本Shigaraki（35°N, 136°E）的MU（中高层大气）雷达和印度尼西亚雅加达附近新建的流星风雷达（6°S, 107°E）的流星回波测量数据，研究了中流层顶附近2日波引起的风速和温度波动特征。1993年7月12日至19日，一波持续2天的海啸在茂垣和雅加达明显增强。温度和北风的波动在志垣县为正相，在雅加达为反相，这与假设罗斯-重力波的预测相一致。两个地点之间波动的相位滞后表明，该波向西传播，纬向波数为3。利用频率谱和温度场和风场的复杂解调技术检查了雅加达2日波的季节变化，发现在每个半球的夏季相应期间明显增强，特别是1993年1月。在南半球和北半球夏季，主导波周期相对稳定，集中在以47小时和49小时为中心的狭窄范围内。当北风分量出现增强的2日波时，温度的相位变化比北风的相位变化早180°~ 225°，说明它们在南半球是反相位关系。这些结果有力地支持了中层顶附近的2日波是纬向波数为3的罗斯重力波的（3,0）模态的解释。
We study in this paper characteristics of both wind velocity and temperature fluctuations due to a 2-day wave near the mesopause, by means of meteor echo measurements with the MU (middle and upper atmosphere) radar in Shigaraki, Japan (35°N, 136°E) and a meteor wind radar, newly constructed near Jakarta, Indonesia (6°S, 107°E). A 2-day wave was conspicuously enhanced on July 12-19, 1993, at both Shigaraki and Jakarta. Fluctuations of temperature and northward wind were inphase in Shigaraki, and they became antiphase in Jakarta, consistent with a prediction assuming a Rossby-gravity wave. The phase lag of the fluctuations between the two sites suggested that this wave propagated westward with a zonal wavenumber of 3. Seasonal variations of the 2-day wave in Jakarta were examined by using a frequency spectrum and complex demodulation technique for temperature and wind fields, finding clear enhancements during periods corresponding to summer months in each hemisphere, especially in January 1993. The dominant wave period was fairly stable and was confined in a narrow range centered around 47 and 49 hours during summer months of the southern and northern hemispheres, respectively. The phase variations of temperature preceded those for the northward wind by 180°-225° when an enhanced 2-day wave was seen in the northward component, indicating their antiphase relation in the southern hemisphere. These results strongly support the interpretation of the 2-day wave near the mesopause as the (3, 0) mode of a Rossby-gravity wave with zonal wavenumber of 3.