新疆昭苏彩虹环流特征及其可预报性分析
Characteristics and Predictability of Rainbow Circulation in Zhaosu
中文摘要：
采用2017—2019年NCEP/NCAR逐日2.5°×2.5°再分析数据和伊犁州昭苏气象站彩虹观测记录，对昭苏出现彩虹的环流特征进行了分型，并通过对数值模式预报产品的检验分析了昭苏彩虹的可预报性。结果表明：昭苏4—9月都可观测到彩虹，绝大多数出现在17—22时；500 hPa的环流可归纳为西南气流型、偏西气流型、脊区型和西北气流型4种环流型，700 hPa存在风的辐合或切变，叠加地形的抬升作用，使对流不稳定强烈发展，对流系统生成，利于对流性降水的出现；ECMWF模式对环流形势的预报时效可达7 d；提出了经过实践检验的昭苏彩虹预报思路，概率约为65%。
中文关键词：
彩虹特征，环流分型，可预报性，昭苏
KeyWords：
rainbow’s characteristics, circulation classification, predictability, Zhaosu
Abstract：
Using NCEP / NCAR daily 2.5°×2.5°reanalysis data from 2017 to 2019 and the rainbow observation records of Zhaosu meteorological station in Yili, the circulation characteristics and its predictability of rainbow in Zhaosu are analyzed. The results show that rainbows can be observed from April to September in Zhaosu, and most of them occur at 17?22 o’clock. The circulation situation at 500 hPa can be summarized as four types: southwest flow type, west flow type, ridge type and northwest flow type. There is wind convergence or shear at 700 hPa, and superimposed topographic uplift, the convective instability develop strongly and the convective system is generated, which is conducive to the convective precipitation. The ECMWF model can predict the circulation situation in 7 days. The prediction idea of Zhaosu rainbow is proposed, and the probability is about 65%.