利用 2017-2023 年茅台机场 AWOS（Automated Weather Observing System）自动观测资料、ERA5（ECMWF Reanalysis v5）再分析资料以及美国国家海洋和大气管理局（NOAA）的 ETOPO2v2 地形数据，采用天气学分析、统计分析与诊断分析等方法，对机场低能见度天气特征及其影响因子进行了研究，并利用 HYSPLIT 后向轨迹模型对低能见度天气的水汽源地进行追踪。结果表明：茅台机场全年湿度较高，秋冬季低温、高湿、低风速等特征明显，更有利于低能见度天气的形成和维持。机场全年各月均会出现低能见度天气，其中 10月至次年 2月以及春末夏初低能见度出现日数高于平均值。一天中低能见度天气发生频率从傍晚开始逐渐升高，春季在 06:00-08:00（北京时，下同）发生频率达到最高，夏季和秋季 05:00-07:00发生频率达到最高，冬季 03:00-05:00发生频率达到最高。除较低风速外，影响低能见度天气的主要影响因子还包括地形、环流背景、逆温、温度平流以及水汽条件等。低能见度天气发生时机场风向主要为 WNW，与赤水河谷地形以及冷空气的活动密切相关。春、秋、冬季三季，机场上空高层主要受偏西气流影响，低层偏北气流与偏南气流在云贵高原上交绥形成云贵准静止锋。锋面逆温有利于水汽在近地面聚集达到饱和状态，低能见度天气多发生于锋后冷区中。夏季机场上空逆温多为辐射逆温，低能见度天气以辐射雾为主。HYSPLIT水汽追踪结果表明，低能见度天气1500 m高度主要水汽来源有两个，分别是青藏高原南侧的孟加拉湾和机场西北部的赤水河谷；3000 m高度水汽则主要来源于孟加拉湾。

Using the AWOS（Automated Weather Observing System）automatic observation data at Maotai Air‐ port from 2017 to 2023，ERA5（ECMWF Reanalysis v5）reanalysis data，and the ETOPO2v2 topography data provided by the National Oceanic and Atmospheric Administration（NOAA）of the United States. Using methods such as weather analysis，statistical analysis，and diagnostic analysis，this study investigates the characteristics and influencing factors of low visibility weather at airports，and employs the HYSPLIT backward trajectory model to trace the sources of water vapor in low visibility weather. The results show that Maotai Airport has higher humidity throughout the year，with obvious characteristics such as low temperature，high humidity，and low wind speed in autumn and winter，which is more conducive to the formation and maintenance of low visibility weather. Low visibility weather occurs at the airport every month of the year，with the number of low visibility days being higher than average from October to February of the following year and in late spring and early sum‐ mer. The frequency of low visibility weather gradually increases from dusk throughout the day. In spring，the frequency reaches its highest point from 06:00（Beijing Time，same as after）to 08:00 in the morning，in summer and autumn from 05:00 to 07:00，and in winter from 03:00 to 05:00. In addition to low wind speeds，the main factors affecting low visibility weather include terrain，circulation background，inversion，temperature advection，and water vapor conditions. When low visibility weather occurs，the prevailing wind direction at the airport is WNW，which is closely related to the terrain of the Chishui River Valley and the activity of cold air. In spring， autumn and winter，the upper air level above the airport is mainly affected by the westerly airflow，and the lowlevel airflow from the north and the south converge over the Yunnan-Guizhou Plateau，resulting in the Kunming quasi-stationary front. Frontal inversion is beneficial for water vapor to accumulate near the ground and reach saturation. Low visibility weather at the airport typically appears in the cold zone behind the frontal zone. In summer，the temperature inversion over airports is mostly radiation inversion，and low visibility weather is mainly radiation fog. The HYSPLIT water vapor tracking results show that there are two main sources of water vapor at an altitude of 1500 meters during low visibility weather，namely the Bay of Bengal on the south side of the Qing‐ hai-Tibet Plateau and the Chishui River Valley in the northwest of the airport；the water vapor at an altitude of 3000 meters mainly originates from the Bay of Bengal.