The Data Intercomparison of Radiosonde systems during SoWMEX/TiMREX and Applications

碩士 === 國立臺灣大學 === 大氣科學研究所 === 97 === The purpose of this study is to carry out the inter-comparison of radiosondes at Banchiao sounding station on April 14-15, October 4-5 and October 11-12 of 2008. The results are then applied to diagnose the time series of atmospheric profiles over Dungsha island...

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Bibliographic Details
Main Authors: Ya-Hang, 李亞衡
Other Authors: 林博雄
Format: Others
Language:zh-TW
Published: 2009
Online Access:http://ndltd.ncl.edu.tw/handle/48242510906053190069
Description
Summary:碩士 === 國立臺灣大學 === 大氣科學研究所 === 97 === The purpose of this study is to carry out the inter-comparison of radiosondes at Banchiao sounding station on April 14-15, October 4-5 and October 11-12 of 2008. The results are then applied to diagnose the time series of atmospheric profiles over Dungsha island in SoWMEX/TiMREX. The radiosondes used in SoWMEX / TiMREX are Graw DFM-06, Vaisala RS92, and Meisei RS2-80 own different types of sensors and measurement methods. In order to understand the deviation among these radiosondes, 12 groups of co-flights were launched, which was referred the WMO radiosondes’ inter-comparison campaign at Vacoas, Mauritius in 2005. From these 12 inter-comparison experiments, we provided the deviation of Graw DFM-06 and Meisei RS2-80 compared to Vaisala RS92 and the curve-fitting function for correction. For pressure deviation, the results indicated that DFM-06 is lower 1 hPa than the RS92 and decrease the deviation with height. RS2-80 has over ~10 hPa after launch and deviation decreased to 2.5 hPa with height. For temperature deviation, DFM-06 was 0~0.2℃ near the surface and 0.3~0.75℃ near the tropopause to RS92. Their temperature deviation has good linear regression. RS2-80 has diurnal deviation about 0.5~1.0℃ to RS92. For relative humidity deviation, three radiosondes close to each other but RS92 has 5~10% dry deviation over 300hPa than the other two. According to these inter-comparison results, we validated the RS2-80 sounding data at Dongsha Island in SoWMEX / TiMREX and diagnosed the characteristics of time evaluation of Monsoon signal over North South China Sea region. We found the pressure and temperature field has reasonable decrease during storm systems (higher humidity) passing the island, specially on the lower atmosphere layer (1500~6000m). The zonal wind field in the lower atmosphere also turns to the east abruptly with northward wind component, and the lower level jet (LLJ) could be identified clearly. The air temperature of total column has significant contrast before and after the monsoon onset, too.