- 期刊
北台灣S與C波段雙偏極化雷達定量降雨估計之比較
Comparison of Quantitative Precipitation Estimation in Northern Taiwan Using S- and C-band Dual-Polarimetric Radars
摘要
未來台灣將由S 與C 波段雙偏極化雷達組成降雨雷達網，而雙偏極化雷達參數（如KDP、ZDR）會因電磁波波長差異而有不同的特性，進而影響其應用於降雨估計的表現。為促進各波段雷達定量降雨估計產品的整合，本研究利用國立中央大學二維雨滴譜儀資料，依月份針對春雨、梅雨、午後對流、颱風以及冷鋒鋒面等降雨類型進行分類，並透過T-Matrix 散射模擬雙偏極化雷達參數，求得不同波段雷達各降雨類型之降雨估計關係式：R(Z)、R(KDP)、R(Z,ZDR)及R(KDP,ZDR)。本研究評估資料處理程序與各類降雨估計方法，分析其對S 與C 波段雙偏極化雷達降雨估計的影響。研究個案選自2014 至2015 年由氣象局S 波段與中央大學C 波段雷達共同觀測之7 組個案累計15 小時，透過地面雨量站資料校驗雷達降雨估計的表現。分析結果顯示：(一)套用對應降雨類型公式可改善雷達降雨估計的表現；(二)利用ФDP修正能量衰減、自洽法(Self-consistency)修正Z 偏差量與濕天線罩效應的衰減量，皆能明顯改善S 與C波段雷達降雨估計的表現；(三)兩雷達降雨估計皆以KDP 參數之組合型公式(Hybrid)有最佳表現；(四)當雷達資料樣本數相近時，短波段雷達其KDP 參數於降雨估計略具優勢，有較低的相對均方根差與較高的相關係數。
並列摘要
The operational radar network in Taiwan will be composed with S and C-band dual-polarimetric radars to monitor extreme precipitation. Various polarimetric parameters of different wavelength radars have distinct advantages and disadvantages in term of quantitative precipitation estimation (QPE). Four different QPE relationships, namely R(Z), R(K_(DP)), R(Z,Z_(DR)) and R(K_(DP),Z_(DR)), of each rain type are obtained from National Central University 2D-Video disdrometer data and applied to seven events observed by both RCWF S-band and NCU C-Pol radars from 2014 to 2015. The goal of this study is to investigate the performances of radar-based QPE from different wavelengths by comparing with 96 rain gauges. The results indicate that: (1) The QPEs are improved after applied into the corresponding rain-type coefficients with respect to general ones. (2) Both the attenuation correction by ФDP algorithm and the wet radome correction by self-consistency method greatly improve the QPEs from RCWF and NCU C-Pol radars. (3) The QPEs from KDP-based relationships which combine with R(Z) are more accurate than Z-based relationships. (4) When two radars have comparable sampling data, NCU C-Pol radar shows the advantage of KDP parameter for QPE at shorter wavelength with lower relative root mean square error and higher correlation coefficient.
延伸閱讀
- 邱亮瑜（2016）。利用自動化雨滴譜儀進行北台灣雨滴粒徑分布量測及降雨動能推估之研究〔碩士論文，國立臺灣大學〕。華藝線上圖書館。https://doi.org/10.6342/NTU201602503
- 陳正達（2000）。由不同的觀測反演估計、分析與模擬實驗檢視台灣鄰近區域降雨的長期氣候分布特性。大氣科學，28(2)，115-142。https://www.airitilibrary.com/Article/Detail?DocID=02540002-200006-28-2-115-142-a
- 劉崇治、林裕豐、戴世忠、趙俊傑、劉振榮（2007）。SSM/I衛星資料在估算侵台颱風降雨之初步研究。大氣科學，35(1)，51-67。https://www.airitilibrary.com/Article/Detail?DocID=02540002-200703-35-1-51-67-a
- 王尹懋、陳正達、張智昇、駱世豪（2015）。氣候變遷影響下台灣之颱風降雨分佈第一部份：數值模式控制實驗之校驗。大氣科學，43(2)，151-169。https://www.airitilibrary.com/Article/Detail?DocID=02540002-201506-201507200004-201507200004-151-169
- 蔣忠廷（2007）。A Study of Precipitation-Regime Separation in Taiwan—Convective and Stratiform Components〔碩士論文，國立中央大學〕。華藝線上圖書館。https://www.airitilibrary.com/Article/Detail?DocID=U0031-0207200917345710