Comparison of COSMIC radio occultation refractivity profiles with radiosonde measurements
Comparison of COSMIC radio occultation refractivity profiles with radiosonde measurements
复制标题
DOI：
10.1007/s00376-009-8066-y
复制
发表时间：
2009-11
影响因子：
5.8
通讯作者：
Xiaohua Xu;Jia Luo;C. Shi
中科院分区：
文献类型：
--
作者：
Xiaohua Xu;Jia Luo;C. Shi
近年来，利用全球定位系统（GPS）信号的无线电掩星（RO）技术已被用于获取中性大气中的大气参数廓线。本文将2006年7月15日至2007年7月15日期间，由气象、电离层和气候星座观测系统（COSMIC）使命获得的RO活动廓线与澳大利亚气象局提供的38个无线电探空站的观测数据进行了统计比较。首先比较了不同的配置标准，最后用3小时内和300公里的无线电探空仪测量的COSMIC RO探测进行统计比较。结果表明，在0-30 km高度，COSMIC卫星的大气活动廓线与38个测站的探空资料吻合良好，大气活动的平均相对绝对偏差小于0.5%。经纬向比较表明，低纬和中纬地区对流层低层的大气环流活动存在负偏差，低纬地区对流层低层的大气环流活动存在较大的标准偏差，标准偏差可达0.6%。通过比较COSMIC RO活动剖面和3个极地站探空资料，发现2006年9月至2007年8月期间，南极地区夏季和秋季的GPS RO剖面精度优于春季和冬季。
In recent years, radio occultation (RO) technology making use of global positioning system (GPS) signals has been exploited to obtain profiles of atmospheric parameters in the neutral atmosphere. In this paper, the RO refractivity profiles obtained from the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) mission are statistically compared with the observations of 38 radiosonde stations provided by the Australian Bureau of Meteorology during the period from 15 July 2006 through 15 July 2007. Different collocation criteria are compared at first, and COSMIC RO soundings that occur within 3 hours and 300 km of radiosonde measurements are used for the final statistical comparison. The overall results show that the agreements between the COSMIC refractivity profiles and the radiosonde soundings from the 38 stations are very good at 0–30 km altitude, with mean absolute relative refractivity deviations of less than 0.5%. Latitudinal comparisons indicate that there are negative refractivity deviations in the lower troposphere over the low latitude and middle latitude regions and large standard deviations exist in the lower troposphere of low latitude regions, which can reach up to ≈6%. The comparisons of COSMIC RO refractivity profiles and radiosonde observations for 3 polar stations in four different seasons indicate that the accuracy of GPS RO profiles is better in the Austral summer and autumn than in the Austral spring and winter during the year from September 2006 to August 2007.