北京MST雷达探测中间层-低热层观测结果初步分析

北京MST雷达是子午工程建设的国内仅有的两部MST雷达之一,为研究其在中间层-低热层MLT区域的探测能力以及数据可靠性,本文应用北京MST雷达2012、2013两年高模式数据,从数据获取率、与廊坊流星雷达测风对比以及风场时空分布特征三个方面进行初步分析.结果是:(1)数据获取率日变化特征为:白天65~100km均可获取数据,数据获取率的高值区主要集中在70~80km,最大值可达80%;夜间主要集中在80~100km,数据获取率在30%及以下.表明该MST雷达白天可以探测到电离层D层和E层低层,夜间D层消失,只探测到E层低层.季节变化特征为:夏季白天可获取数据的时间和高度区间都比较大,春季次之,冬季最小.夏季白天以及日落后1h内可探测到120km.(2)对北京MST雷达与廊坊流星雷达2012年5月份、80~100km高度区间测量的水平风进行对比分析,二者测风结果在时空分布上有很好的一致性,表明MST雷达探测数据是可靠的.(3)2012年和2013年相应月份平均的纬向风、经向风时空分布特征有较高的一致性,并与HWM07模式结果也基本一致.上述初步分析结果表明,北京MST雷达对中间层-低热层60~120km高度区域已具备较强的探测能力,所得结果将可用于MLT过程揭示与驱动因子研究,并可与该高度上其他探测手段作综合研究.

Preliminary analysis of Beijing MST radar observation results in the mesosphere-lower thermosphere

Beijing MST radar is one of the Chinese Meridian Project constructions of only two domestic MST radars. It was built by Institute of Atmospheric Physics, Chinese Academy of Sciences, located at Xianghe field observatory,Hebei province (39.754°N,116.962°E). System integrated test was finished in May 2011 and completed acceptance in the end of July 2011. After 1-month joint tests from 21 September 2011 to 20 October 2011, Beijing MST radar operated continuously to observe real-time winds and turbulence in the altitude range of 3.5~10 km (low mode), 11~25 km (middle mode) and 60~90 km (even above) (high mode). Beijing MST radar operates at 50 MHz with a peak power of 172kW and 10⁴ m² of antenna area. The purpose of this paper is to investigate the detection capability and data reliability of Beijing MST radar in the mesosphere-lower thermosphere (MLT) region.#br#Two years of data (January 2012 to December 2013) in high mode were used. From the aspect of data acquisition rate, comparison of wind measurements with the nearby Langfang meteor radar and spatial and temporal characteristics of wind, preliminary analyses were made.#br#Analysis results indicate that:(1) Data acquisition rate shows diurnal variation characteristics:during daytime the MST radar can obtain data in 65~100 km. High-ratio areas of data acquisition rate were mainly concentrated in the 70~80 km with a maximum of up to 80%.At nighttime available data altitude range focused on 80~100 km with data acquisition rate at 30% and below. This indicates that the MST radar can detect ionospheric D layer and lower E layer during daytime, at night time D layer disappears, only lower E layer detected. Seasonal variation characteristics of data acquisition rate are that the time and height range of available data were large in summer daytime, followed by spring, and winter was minimum. During summer daytime and until one hour after sunset, the MST radar can detect up to 120 km. (2) Horizontal winds in 80~100 km measured by Beijing MST radar and Langfang meteor radar in May 2012 were compared. The results showed good agreement in spatial and temporal distribution, indicating that the data of MST radar observations is reliable. (3) The spatial and temporal distribution of averaged zonal wind and meridional wind of corresponding month in year 2012 and 2013 had high consistency, and were also fairly consistent with HWM07 model results.#br#The preliminary analysis results above show that the Beijing MST radar has strong detection ability in the MLT region (60~120 km), and the observed data can be furtherly used to reveal the processes and driving factors of the MLT region.