上海虹桥机场低能见度天气过程中的气象要素特征分析

The Characteristics of Meteorological Elements in Low Visibility Conditions at Shanghai Hongqiao Airport

利用上海虹桥机场1986-2014年地面例行观测报告结果对机场低能见度天气下的多种气象要素特征进行了统计和分析。研究发现:虹桥机场低能见度天气下气温处于10-15℃之间的概率最高,在气温≤0℃或>20℃时基本不会有低能见度天气发生;近五年来机场低能见度天气有在"更暖"的背景环境下发生的趋势。低能见度天气下机场主导风向在近年来以偏北风和西南风为主,强度较强的低能见度天气主导风向多集中于偏北和偏南两个方向;风速为0-2 m/s的概率最大,且具有风速越小能见度数值越低的特征。机场低能见度天气下相对湿度为90%-95%的出现比率最高,随着能见度的降低相对湿度处于这一区间的概率增大,且近五年来机场发生低能见度天气的背景环境趋于"更加干燥"。

Based on the routine surface meteorological observations during the period of 1986- 2014, the characteristics of meteorological elements in low visibility conditions have been systematically and statistically analyzed. Results show that low visibility conditions appear more frequently at the airport with temperature between 10℃ and 15℃ and hardly happen when temperature falling out of 0- 20℃. In recent five years, the occurrence of low visibility conditions coincides with a wanner weather. Northerly and southwesterly winds dominate in low visibility conditions, while northerly and southerly winds dominate in extreme low visibility conditions. In low visibility conditions, the wind speed falls into the range of 0-2m/s and is positively correlated with visibility conditions. Meanwhile, the relative humidity is between 90% and 95%. The lower visibility the condition is in, the larger probability the relative humidity falls into this range. Observations in recent years indicate that low visibility conditions tend to appear in a ＂drier＂ environment at Hongqiao Airport.