气象学报
氣象學報
기상학보
ACTA METEOROLOGICA SINICA
2014年
6期
1231-1244
,共14页
郭凤霞%马学谦%王涛%陈聪
郭鳳霞%馬學謙%王濤%陳聰
곽봉하%마학겸%왕도%진총
X 波段双线偏振雷达%雷暴云%粒子识别%模糊逻辑法
X 波段雙線偏振雷達%雷暴雲%粒子識彆%模糊邏輯法
X 파단쌍선편진뢰체%뇌폭운%입자식별%모호라집법
Xˉband dualˉpolarization Doppler weather radar%Thundercloud%Hydrometeor identification%Fuzzy logic method
为了进一步认识雷暴云中影响起电的主要水成物类型,联合714XDP 天气雷达观测到的偏振参量(Z H 、Z DR 、K DP 和ρHV ),在利用模糊逻辑方法的基础上引入温度(T),对中国西北地区夏季雷暴云中的水成物类型进行识别,将水成物分为11种。参考 S 和 C 波段及少量的 X 波段偏振雷达的粒子识别研究,得到11种粒子对应的各偏振参量阈值。分析了2007年7月24日的一次观测过程几个时刻的偏振参量、地面电场、放电频数及识别结果,并与利用三维雷暴云动力电耦合数值模式模拟出来的粒子分布结果做了对比。结果表明,选取的偏振参量阈值基本合理,采用的模糊逻辑方法能有效、合理地识别出雷暴云内水成物的相态和分布,而且利用 K DP 可以大致判断云内电荷区。
為瞭進一步認識雷暴雲中影響起電的主要水成物類型,聯閤714XDP 天氣雷達觀測到的偏振參量(Z H 、Z DR 、K DP 和ρHV ),在利用模糊邏輯方法的基礎上引入溫度(T),對中國西北地區夏季雷暴雲中的水成物類型進行識彆,將水成物分為11種。參攷 S 和 C 波段及少量的 X 波段偏振雷達的粒子識彆研究,得到11種粒子對應的各偏振參量閾值。分析瞭2007年7月24日的一次觀測過程幾箇時刻的偏振參量、地麵電場、放電頻數及識彆結果,併與利用三維雷暴雲動力電耦閤數值模式模擬齣來的粒子分佈結果做瞭對比。結果錶明,選取的偏振參量閾值基本閤理,採用的模糊邏輯方法能有效、閤理地識彆齣雷暴雲內水成物的相態和分佈,而且利用 K DP 可以大緻判斷雲內電荷區。
위료진일보인식뇌폭운중영향기전적주요수성물류형,연합714XDP 천기뢰체관측도적편진삼량(Z H 、Z DR 、K DP 화ρHV ),재이용모호라집방법적기출상인입온도(T),대중국서북지구하계뇌폭운중적수성물류형진행식별,장수성물분위11충。삼고 S 화 C 파단급소량적 X 파단편진뢰체적입자식별연구,득도11충입자대응적각편진삼량역치。분석료2007년7월24일적일차관측과정궤개시각적편진삼량、지면전장、방전빈수급식별결과,병여이용삼유뇌폭운동력전우합수치모식모의출래적입자분포결과주료대비。결과표명,선취적편진삼량역치기본합리,채용적모호라집방법능유효、합리지식별출뇌폭운내수성물적상태화분포,이차이용 K DP 가이대치판단운내전하구。
In order to understand the main hydrometeor types affecting the electrification within a thunderstorm,a fuzzy logic algorithm for the classification of hydrometeor based on Xˉband dualˉpolarization Doppler weather radar measurements is deˉ scribed.Four radar parameters,namely,horizontal reflectivity (Z H ),differential reflectivity (Z DR ),specific differential phase (K DP )and correlation coefficient (ρHV ),have been used in the algorithm.Hydrometeor is classified into 11 types which have closed relationships with the nonˉinductive electrification mechanism.The thresholds of polarizatic parameters for the 11 hydroˉ meteor types are obtained by refering to the research results of the hydrometeor classification using Sˉ,Cˉand Xˉband dualˉpoˉ larization weather radars.In addition,environment temperature is added to restrict the altitude range of every hydrometeor type.The hydrometeors of the two convection processes taking place on 24 July 2007 in northwestern China are identified based on this algorithm.Furthermore,the characteristics of the radar parameters,ground electric field and flash frequency are anaˉ lyzed preliminarily.Compared with the 3ˉD thunderstorm electrical model,the results show that the hydrometeor types could be identified effectively.It implies the fuzzy sets of polarimetric parameters and temperature ranges determined are basically valid.The charge regions could be inferred roughly based on the characteristics of K DP .All of these results are helpful for furˉ ther understanding of the electrication mechanism within a thunderstorm.