气象学报
氣象學報
기상학보
ACTA METEOROLOGICA SINICA
2008年
2期
262-273
,共12页
雷达-雨量计%准同雨团样本%同步结合%小时等效反射率.
雷達-雨量計%準同雨糰樣本%同步結閤%小時等效反射率.
뢰체-우량계%준동우단양본%동보결합%소시등효반사솔.
Radar-raingauge%Quasi-same rain volume sample%Synchronously integration%Hourly equivalent reflectivity
文中提出一种基于准同雨团样本概念雷达与雨量计(R&G)的实时同步结合技术.由于存在探测时空和分辨率的两种差异,雷达与雨量计(R&G)的同样本对应历来被视为一道难题.但观测表明,雨量计与其垂直上空雷达的小时累积量(ZOH,QG)存在符合幂律的相关性.以此为基础,提出旨在基本消除时空差异的准同雨团样本概念和5个R&G直接对应关系,着重研究一种简便实用的"时间积分垂直同步采样"TIVS,以及具有幂律形式的ZOH-QG关系.有意义的是在固定指数条件下系数AB或AM,具有Z-R转换和雨量计调整(订正)同步结合于一式的功能,两种设备在探测分辨率上巨大差异而引起的降水估算误差由此得到明显缓解.这种利用ZOH-QG关系估算地面小时降水累积量的方法称为RASIM.经过两个降水个例的试验初步表明,雷达估算半径为230 km内地面区域小时累积降水量的正确率在90%以上,而全过程以站为计的点评估相对误差率平均为20%左右.本文还对时间积分垂直同步采样在具有风漂移效应各种环境风场中的可利用性作了详细分析,揭示了时间积分垂直同步采样方法的物理本质,明确指出这是一种近似的准同雨团样本采样;同时通过分析R&G数据对的分布规律,研究提出了有效的质量控制方法,明显改善了ZOH-QG关系的稳定性和合理性.
文中提齣一種基于準同雨糰樣本概唸雷達與雨量計(R&G)的實時同步結閤技術.由于存在探測時空和分辨率的兩種差異,雷達與雨量計(R&G)的同樣本對應歷來被視為一道難題.但觀測錶明,雨量計與其垂直上空雷達的小時纍積量(ZOH,QG)存在符閤冪律的相關性.以此為基礎,提齣旨在基本消除時空差異的準同雨糰樣本概唸和5箇R&G直接對應關繫,著重研究一種簡便實用的"時間積分垂直同步採樣"TIVS,以及具有冪律形式的ZOH-QG關繫.有意義的是在固定指數條件下繫數AB或AM,具有Z-R轉換和雨量計調整(訂正)同步結閤于一式的功能,兩種設備在探測分辨率上巨大差異而引起的降水估算誤差由此得到明顯緩解.這種利用ZOH-QG關繫估算地麵小時降水纍積量的方法稱為RASIM.經過兩箇降水箇例的試驗初步錶明,雷達估算半徑為230 km內地麵區域小時纍積降水量的正確率在90%以上,而全過程以站為計的點評估相對誤差率平均為20%左右.本文還對時間積分垂直同步採樣在具有風漂移效應各種環境風場中的可利用性作瞭詳細分析,揭示瞭時間積分垂直同步採樣方法的物理本質,明確指齣這是一種近似的準同雨糰樣本採樣;同時通過分析R&G數據對的分佈規律,研究提齣瞭有效的質量控製方法,明顯改善瞭ZOH-QG關繫的穩定性和閤理性.
문중제출일충기우준동우단양본개념뢰체여우량계(R&G)적실시동보결합기술.유우존재탐측시공화분변솔적량충차이,뢰체여우량계(R&G)적동양본대응력래피시위일도난제.단관측표명,우량계여기수직상공뢰체적소시루적량(ZOH,QG)존재부합멱률적상관성.이차위기출,제출지재기본소제시공차이적준동우단양본개념화5개R&G직접대응관계,착중연구일충간편실용적"시간적분수직동보채양"TIVS,이급구유멱률형식적ZOH-QG관계.유의의적시재고정지수조건하계수AB혹AM,구유Z-R전환화우량계조정(정정)동보결합우일식적공능,량충설비재탐측분변솔상거대차이이인기적강수고산오차유차득도명현완해.저충이용ZOH-QG관계고산지면소시강수루적량적방법칭위RASIM.경과량개강수개례적시험초보표명,뢰체고산반경위230 km내지면구역소시루적강수량적정학솔재90%이상,이전과정이참위계적점평고상대오차솔평균위20%좌우.본문환대시간적분수직동보채양재구유풍표이효응각충배경풍장중적가이용성작료상세분석,게시료시간적분수직동보채양방법적물리본질,명학지출저시일충근사적준동우단양본채양;동시통과분석R&G수거대적분포규률,연구제출료유효적질량공제방법,명현개선료ZOH-QG관계적은정성화합이성.
The real time synchronously integrated technique for radar and raingauge (R&G) based on the concept of quasi-same rain volume sample was presented. Because of the presence of temporal and spatial discrepancies as well as resolution differences, the same sample correspondence of R&G has long been a difficult, lasting problem. However, the observations indicate that there exists the correlation conforming to the power-law between hourly accumulation of raingauge measurement QG and radar detected echo aloft over the rain gauge vertically (ZOH). On the basis of this fact, aiming to eliminate the temporal and spatial discrepancies, the concept of quasi-same rain volume sample and the five direct correspondence relationships of R&G are built up. The quite convenient and practical TIVS, i.e. time integral vertical synchronous sampling, and its ZOH-QG relationship with power law are emphatically studied. What has significance is that under the fixed exponent, the coefficient AB or AM can flexibly vary in accordance with the temporal and spatial variability of the natural precipitation, and has a function to synchronously integrate the Z-R conversion and the gauge adjustment into a single equation, thus the precipitation estimation error caused by detecting resolution differences between radar and gauge can be obviously mitigated. It is apparently different from the traditional methods wherein precipitation is estimated by radar and gauge, respectively. The real time synchronously integrated technique using the ZOH-QG relationship to estimate hourly ground rainfall accumulation, is called radar-gauge synchronously integrated method (RASIM). The experiments of two cases show that the correctness rate for area estimation within 230 km is about 90% and the average relative error rate for point estimation over the whole process is about 20%.Through the analysis of effects for various wind drifts in three kinds of environment fields, the physical substance of TIVS has been revealed, definitely suggesting that it is an approximate quasi-sample rain volume sampling. Fortunately, by full demonstration, the better availability has been explained in most weather conditions and confirmed by experimental tests in the paper. By analyzing the data pairs of R&G, the effective quality control method is established which can greatly improve the stability and the reasonability of ZOH-QG relationship. The forecasting product of hourly accumulated precipitation derived by RASIM method has been put into the operational forecasting and has especially played an important part in the short-term quantitative monitoring and forecasting for torrential rain.RASIM needs to be further studied at many aspects, such as to establish more robust theory concerning with quasi-same sample for R&G, to try searching the methods of accurately temporal and spatial coordinating sampling, to make tests and analysis in field for TIVS in various weather systems and conditions, to explore the data quality control technique influenced by wealth systems and its mechanism of evolution, to study the further application of fixed exponent in calculation of rainfall accumulation, to study multiple ZOH-QG relationships and the characters and application of AB(AM) distribution in space, and so on. All these advances will prospectively help to improve the correctness of radar estimated rainfall accumulation.