1999—2018年锦州地区大雾气候特征及成因分析

应用常规气象观测资料、能见度仪观测资料，分析1999—2018年锦州地区大雾气候特征及成因。结果表明：锦州地区雾日年总频次多年平均为33次，存在12 a、6 a和3 a的变化周期。锦州地区典型大雾过程主要分为弱低压槽型、雨后弱高压型。大雾存在日变化。雾前T-T_d为4—14℃，风速为4 m·s^-1以下，偏南风占50%，偏北风占38%，静风占12%；雾发展阶段T-T_d为0—4℃，平均风速为2.2 m·s^-1，偏南风占58%，偏北风占42%；浓雾阶段T-T_d为0—2℃，平均风速为1.9 m·s^-1，偏南风占58%，偏北风占42%；雾减弱到消散阶段T-T_d逐渐升高，平均风速为3.3 m·s^-1，偏北风占58%。大雾期间，均出现逆温和湿层。

Climate characteristics and causes of heavy fog in Jinzhou from 1999 to 2018

Based on the conventional meteorological data and visibility observed by visibility meter, the climate characteristics and causes of heavy fog in Jinzhou area during 1999-2018 were investigated.The results show that the annual number of fog days in Jinzhou has 12-year, 6-year and 3-year cycles, and its climatological normal is 33 days.The typical fog process in Jinzhou area shows an obvious diurnal variation, and is mainly divided into weak low pressure trough type and weak high pressure type after rain according to weather classification.Before the fog occurs, T-T_d is between 4-14 ℃, the wind speed is generally below 4 m·s^-1, the southerly, the northerly and the static wind account for 50%, 38%, and 12%, respectively.During the fog development phase, T-T_d is between 0 and 4 ℃, the average wind speed is 2.2 m·s^-1, the southerly and the northerly winds account for 58% and 42%, respectively.During the dense fog phase, T-T_d is between 0 and 2 ℃, the average wind speed is 1.9m/s, the southerly and the northerly winds account for 58% and 42%, respectively.However, during the fog weakening to the dissipating phase, T-T_d is gradually rising and is over 8.1 ℃, the average wind speed is 3.3 m·s^-1, and the northerly wind accounts for 58%.As the dense fog appears, temperature inversion and wet layer occur in the atmosphere.