The momentum fluxes associated with gravity waves (GWs) significantly vary both in time and space. It is important to qualify the intermittency of GWs because the intermittency largely affects the vertical profile of momentum flux convergences in the middle atmosphere. In this study, 1 year of continuous observation with high time/height resolution and accuracy was provided by the PANSY radar, a Mesosphere‐Stratosphere‐Troposphere (MST) radar at Syowa Station (69.01°S, 39.59°E) in the Antarctic. The PANSY radar is used to study the intermittency of GWs in the troposphere and lower stratosphere. In all seasons, the intermittency is large in the troposphere with Gini coefficients of 0.4–0.6 for absolute momentum fluxes ( ) and 0.4–0.7 for vertical wind variances multiplied by the density ( ). However, the intermittency is small in the lower stratosphere with Gini coefficients of 0.3–0.5 for and 0.2–0.4 for . The seasonal characteristics in the lower stratosphere are different between and : small Gini coefficients are observed in May–July for and in December–February for . Simple model experiments with ideal distributions of GWs as a function of momentum flux magnitude and ground‐based phase velocity are performed. These results indicate that the vertical profiles of the Gini coefficient obtained by the PANSY radar are largely affected by orographic GWs with large amplitudes. The results also suggest that the generation and the partial reflection of GWs play an important role in determining the vertical profile of GW intermittency.

中文翻译：

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PANSY雷达观测揭示的南极对流层和平流层下部重力波的间歇性

与重力波（GWs）相关的动量通量在时间和空间上都有很大变化。确认GW的间歇性很重要，因为间歇性会大大影响中间大气层动量通量收敛的垂直剖面。在这项研究中，由南极Syowa站（69.01 ° S，39.59 ° E）的中层-平流层-热带层（MST）雷达PANSY雷达提供了连续1年的高时间/高度分辨率和精度的连续观测。PANSY雷达用于研究对流层和低平流层中GW的间歇性。在所有季节中，对流层的间歇性都很大，绝对动量通量的基尼系数为0.4-0.6（ ）和0.4-0.7（垂直风的方差）乘以密度（ ）。但是，平流层下部的间歇性很小，对于的基尼系数为0.3-0.5，对于的基尼系数为0.2-0.4 。平流层下层之间的季节特征在和之间有所不同：在5月至7月和12月至2月，观测到小的基尼系数。。进行了简单模型实验，其中理想的GWs分布是动量通量大小和地基相速度的函数。这些结果表明，由PANSY雷达获得的基尼系数的垂直剖面在很大程度上受到大幅度地形GW的影响。结果还表明，GW的生成和部分反射在确定GW间歇的垂直剖面中起着重要作用。