用日定时观测能见度划分沙尘暴强度存在的问题

Problems Existed in Duststorm Intensity Division when Divided by Daily Timed Observed Visibility

选取宁夏24个气象站1955—2003年沙尘暴观测资料及其沙尘暴出现当日的能见度定时观测资料,分析研究了宁夏单站沙尘暴天气强度划分时存在的问题,结果表明:用沙尘暴当日定时观测最小能见度资料划分沙尘暴天气强度存在很大的片面性,有53%的沙尘暴天气无法划分其强弱、69%的沙尘暴天气发生在非定时观测时间段内,通过典型个例,对比分析了日定时观测最小能见度对沙尘暴天气强度划分的影响和存在的偏差,为历史沙尘暴强度的划分提供参考。

The duststorm observational data and the timed observational visibility data in the same day of Ningxia 24 stations from 1955 to 2003 were selected to analyze the problems existed in intensity division of duststorms in single station. The result shows that to divide the intensity of duststorm by the minimum timed observational visibility data in the same day has big unilateralism, the intensity of 53 % duststorms can＇t be divided and, 69 % duststorms happened in unobserved time. Based on typical cases, the problems of applying daily minimum visibility in intensity division of duststorms and its deviation were analyzed, which has provided reference for the intensity division of historical duststorms.