| DC 欄位 |
值 |
語言 |
| DC.contributor | 大氣科學學系 | zh_TW |
| DC.creator | 吳佳靜 | zh_TW |
| DC.creator | Chia-Jing Wu | en_US |
| dc.date.accessioned | 2024-11-21T07:39:07Z | |
| dc.date.available | 2024-11-21T07:39:07Z | |
| dc.date.issued | 2024 | |
| dc.identifier.uri | http://ir.lib.ncu.edu.tw:444/thesis/view_etd.asp?URN=111621015 | |
| dc.contributor.department | 大氣科學學系 | zh_TW |
| DC.description | 國立中央大學 | zh_TW |
| DC.description | National Central University | en_US |
| dc.description.abstract | 由於臺灣具有高密度雷達網的優勢，許多區域能夠同時被三座以上雷達觀測到，本研究採用解三條徑向風和雷達間幾何關係的聯立方程組所獲得的垂直風場資訊，作為多都卜勒雷達合成反演風場技術 (Wind Synthesis System using Doppler Measurements, 簡稱WISSDOM) 的價值函數所使用的資料，以提升WISSDOM系統對垂直速度的反演能力。嘗試解決利用雷達資料反演垂直風場時，由於徑向風方程中z/r分量較小，導致垂直速度普遍低估的問題。本研究會先透過觀測系統模擬實驗 (Observing System Simulation Experiment, 簡稱OSSE) 評估此新價值函數對於提升WISSDOM系統反演垂直速度能力的可行性，接著進一步針對2022年劇烈降水觀測活動TAHOPE IOP #3的真實個案，測試新約束條件在真實大氣情境下的應用效果。結果顯示，此新方法無論是在OSSE模擬個案還是真實個案中，皆可使垂直速度反演結果在量值上有增強的表現。然而，研究過程中也發現，此新方法所解出的垂直風場資訊於徑向風資料的品質要求較高，加上目前可用於驗證垂直速度的觀測資料有限，因此新方法的反演結果仍需進一步驗證其可信度。未來在利用三徑向風方程求解風場的矩陣運算中，幾何矩陣的條件數結果可作為觀測活動中儀器設置的考量，使垂直風場反演結果有直接的觀測資料可進行驗證。 | zh_TW |
| dc.description.abstract | Taiwan has a high-density radar network. Many regions can be monitored simultaneously by more than three radars. This study utilizes vertical wind field information derived from solving the simultaneous equations of the geometric relationship between three radial winds and radar position. This information is then used as a new constraint in WISSDOM (Wind Synthesis System using Doppler Measurements) to improve WISSDOM′s ability to retrieve vertical velocity. This study aims to address a problem that has persisted for over a decade. The vertical velocity retrieved from radar data has been consistently underestimated due to the small z/r component in the radial wind equation.
In this study, an Observing System Simulation Experiment (OSSE) is first used to evaluate the feasibility of the new constraint to improve vertical velocity retrieval in WISSDOM. Subsequently, to test its performance in real atmospheric conditions, the new constraint is applied in the real case using data from the TAHOPE IOP #3 (Heavy Rain Observation Experiment in 2022). The results show that the new method enhances the magnitude of the vertical velocity retrieved, both in OSSE simulations and real case. However, the study also reveals that the vertical wind information derived from this new method is highly sensitive to the quality of the radial wind data. In addition, the vertical velocity observations currently available for verification are limited. Therefore, the retrieval results of this new method still require further validation to confirm their reliability. In the future, the condition number results of the geometric matrix in the matrix operations for solving the wind field using the three radial wind equations can be utilized as a consideration for instrument setup during observational campaigns. This ensures that the retrieved results of the vertical velocity are validated with direct observational data. | en_US |
| DC.subject | 垂直風速反演 | zh_TW |
| DC.subject | 都卜勒雷達徑向風方程 | zh_TW |
| DC.subject | 多都卜勒氣象雷達三維風場合成 | zh_TW |
| DC.subject | vertical velocity retrieval | en_US |
| DC.subject | Doppler radar radial wind equation | en_US |
| DC.subject | multiple–Doppler radar 3D wind synthesis | en_US |
| DC.title | 以徑向風聯立方程的直接解改善多都卜勒雷達風場合成技術反演垂直速度之可行性評估 | zh_TW |
| dc.language.iso | zh-TW | zh-TW |
| DC.title | A feasibility study of improving the retrieved vertical velocity in multiple–Doppler radar wind synthesized technology using the direct solution of radial wind equations | en_US |
| DC.type | 博碩士論文 | zh_TW |
| DC.type | thesis | en_US |
| DC.publisher | National Central University | en_US |