Estimate of Turbulent Energy Dissipation Rate From the VHF Radar and Radiosonde Observations in the Antarctic
Estimate of Turbulent Energy Dissipation Rate From the VHF Radar and Radiosonde Observations in the Antarctic
复制标题
DOI：
10.1029/2018jd029521
复制
发表时间：
2019-03
期刊：
影响因子：
--
通讯作者：
M. Kohma;Kaoru Sato;Y. Tomikawa;K. Nishimura;Toru Sato
中科院分区：
文献类型：
--
作者：
M. Kohma;Kaoru Sato;Y. Tomikawa;K. Nishimura;Toru Sato
本研究估算了2015年10月至2016年9月南极Syowa - Mesosphere -平流层-对流层/非相干散射雷达（PANSY雷达）项目1年观测的湍流动能耗散率（TKEDRs），并将结果与基于Thorpe方法的无线电探空测量结果进行了比较。基于雷达的估计表明，在1.5-19 km高度范围内，Syowa站的TKEDR约为10−5-10−3 m2/s3。以索普方法的比例常数（索普尺度与奥兹米多夫尺度之比）为单位，基于无线电探空仪的测量结果显示，TKEDR值比基于雷达的估计值大2-5倍。无线电探空和雷达估算的TKEDR在对流层中高层的差异大于在平流层的差异。根据以往的观测和数值研究，Thorpe方法倾向于高估深部倾覆层的TKEDR。证实了翻转层的深度与基于无线电探空仪和基于雷达的估计之间的差呈负相关。季节变化也被检查。利用距离局地对流层顶高度的分析表明，在南方夏季，对流层顶附近的TKEDR局地极大值特别明显。这可能与南极平流层中重力波活动的季节性有关。
This study estimated the turbulent kinetic energy dissipation rates (TKEDRs) from 1‐year observations of the Program of the Antarctic Syowa Mesosphere‐Stratosphere‐Troposphere/Incoherent Scatter radar (PANSY radar) from October 2015 to September 2016 and compared the results with estimates from radiosonde measurements based on Thorpe's method. The radar‐based estimates showed that the TKEDR at Syowa Station was on the order of 10−5–10−3 m2/s3 in the altitude range of 1.5–19 km. Taking the proportional constant for Thorpe's method (the ratio of the Thorpe scale to Ozmidov scale) as unity, the radiosonde‐based measurements show values of TKEDR larger than radar‐based estimates by a factor of 2–5. The difference in the TKEDR between radiosonde‐ and radar‐based estimates is larger in the middle and upper troposphere than in the stratosphere. According to previous observational and numerical studies, Thorpe's method tends to overestimate the TKEDR for deep overturning layers. It is confirmed that the depth of the overturning layer is negatively correlated with the difference between radiosonde‐ and radar‐based estimates. The seasonal variation was also examined. An analysis using the distance from the local tropopause level showed that the local maximum in the TKEDR around the tropopause is particularly clear in austral summer. This is likely connected to the seasonality in the gravity wave activity in the Antarctic stratosphere.