Page 236 - 《高原气象》2023年第1期

高 原 气 象 42 卷
232

The Evaluation of Return Radiosonde Temperature using GNSS

Radio Occultation Retrievaled Temperature

1， 2
3， 4
RONG Na ， YANG Shengpeng ， WANG Jincheng ， WANG Dan 3， 4
1， 2
（1. College of Atmospheric Sciences， Nanjing University of Information Science & Technology， Nanjing 210044， Jiangsu， China；
2. Joint Center for Data Assimilation Research and Applications， Nanjing University of Information Science &
Technology， Nanjing 210044， Jiangsu， China；
3. Numerical Weather Prediction Center of China Meteorological Administration， Beijing 100081， China；
4. National Meteorological Center， Beijing 100081， China）

Abstract： It is necessary to evaluate the quality of a new type of observation data before using it for data assimi‐
lation. Based on GNSS radio occultation （RO） and ERA-Interim reanalysis data， the quality of temperature in
the ascent， drift and descent stage of return radiosonde has been analyzed and evaluated. In the drift stage using
the method of Cressman to interpolate the temperature of return radiosonde and compare with the dry temperation
（T ） of RO， the results show that there is an obvious positive deviation in return radiosonde temperature data
dry
caused by the heating of solar radiation in the daytime and a weak negative deviation at night. A further verify of
the above results by comparing between ERA-Interim reanalysis， RO T and return radiosonde. The average
dry
temperature bias between the drift stage and RO T evoluting with local time ranges is 7~10 ℃ in daytime and
dry
-4~0 ℃ at night. The results show that the precision of night temperature observations of return radiosonde reach‐
es the breakthrough target defined by the WMO（world meteorological organization）. The temperature between
the ascent and descent stages in return radiosonde and the wet temperation （T ） of RO shows a good consisten‐
wet
cy， which the mean bias ranges is -1~1 ℃ in ascent stage as well as below 13 km in descent stage， this bias
slightly increases and ranges is 1~3 ℃ above 13km in descent stage. On the whole， the quality of the temperature
data in the ascending （descending） stage of return radiosonde is better than the drift stage observations. Mean‐
while， the descend stage has the function of space-time encryption for the radiosonde observation， and the data
quality meets the application of numerical weather forecast and other analysis study fields.
Key words： Return radiosonde； intensive radiosonde observations； cross comparison； temperature deviation