• 作者： 陳萬金; 劉振榮
• 作者服務機構： 中正理工學院應用物理系; 中央大學太空及遙測研究中心
• 中文摘要： 由10個個案綜合的反演結果顯示，加入AVHRR資料的TOVS反演結果的確比不加入的結果有所改善，高度場方面在中低對流層均方根差異平均約有5m的改善；溫度場整體均方根差異平均約有0.2K的改善，但以850 mb以下較明顯；而濕度場方面，整體上並沒有多大的差異，只有在900 mb以下均方根差異平均約有0.1 g/Kg的改善。加入AVHRR資料改善的程度並不如期望中的顯著，其主要原因是因為同時物理反演的二步驟反演過程過度倚重MSU資料，所以AVHRR高解析度的優點被掩蓋住了，這一點可由比較分別用HIRS+AVHRR資料與HIRS資料反演的結果得到驗證。在不使用MSU資料的情況下，AVHRR資料的加入使得高度場均方根差異有顯著的改善，平均約20 m；另溫度場均方根差異亦有顯著的改善，平均約1.5 K。 研究中亦探討雲量多寡對反演結果的影響，結果顯示在重力位高度和溫度方面反演的結果有隨雲量增多而漸差的趨勢，但在水汽混合比方面則並無此現象。除了加入AVHRR資料對TOVS反演結果的改善外，另外一般不加入AVHRR資料的反演結果，亦較以往國內在此方面的研究有所進步。反演的結果和傳統探空觀測值比較，重力位高度、溫度及水汽混合比的均方根差異值分別為80m、2K和2g/Kg“.
• 英文摘要： Retrieval results which use or do not use advanced very high resolution radiometer (AVHRR) data,respectively, are verified by data contained in 10 satellite passes from 7 continuous days and prove thatthe results improve if AVHRR data are applied. In geopotential height retrieval results, there was a 5m improvement in the root mean square difference (RMSD) when compared with colocated traditionalsounatng data in the low ana middle troposphere. in temperature retrieval results, tnere was about a 0.2K improvement, especially below 850 mb. For water vapor mixing ratio retrieval results, overall, therewas little improvement, except about a 0.1 g/Kg improvement found at levels below 900 mb. The reasonfor the only slight improvement was the heavy dependence of the simultaneous physical scheme onmicrowave sounding unit (MSU) radiance data (Smith et al.,1985), which was verified by comparingthe results retrieved using high-resolution infrared sounder (HIRS)＋AVHRR data and HIRS data only.The RMSD of the geopotential field had significant improvement, about 20 m, and the RMSD of temperaturefield also had great improvement, about 1.5 K after AVHRR data were added into the television and infraredobservation satellite (TIROS) operational vertical sounder (TOVS) retrievals. To investigate the effect of retrieval temperature and moisture profile with various effective cloudamounts, the retrieval results are divided into four groups according to the effective cloud amount. Itis shown that there is a tendency for the RMSD of temperature profile to increase with the effectivecloud amount, but that there is no relationship between the accuracy of the RMSD and effective cloudamount in moisture retrieval. In addition to the improvement obtained by merging AVHRR data into TOVS retrievals, our resultsare also better than those of previous studies by other researchers (Yen and Wang, 1986; Liu, 1988; Liu,1990; Liu and Chen, 1992). The RMSD for the retrieval results in this study are about 80 m, 2 K, and2 g/Kg in geopotential height, temperature and water vapor mixing ratio, respectively, when comparedwith traditional radiosonde observations.
• 中文關鍵字： retrieval; effective cloud amount; cloud-clearing; weighting function
• 英文關鍵字： --