乌鲁木齐国际机场冬季一次雪后间歇性冻雾天气成因分析
Analysis of the Causes of Intermittent Freezing Fog Weather after a Snowfall in Winter at Urumqi International Airport

利用常规高空地面、FNL 1？ × 1？再分析资料、地面气象自动站及微波辐射计资料对2023年12月30日~2024年1月2日乌鲁木齐国际机场冬季的一次雪后间歇性冻雾天气进行成因分析，发现：(1) 此次间歇性冻雾天气过程是在500 hPa、700 hPa偏西气流或暖脊控制配合850 hPa较强的暖平流天气环流背景下产生的。(2) 地面温度变化是乌鲁木齐机场12月30日~1月2日冻雾天气有间歇性的重要原因之一。温度降低，地面转偏北风均有利于乌鲁木齐机场冻雾的维持与发展。(3) 前期受北支槽东移影响，北疆大部、天山山区有一次小雪天气过程，为间歇性冻雾天气提供较好的水汽补充。(4) 稳定层结是冻雾维持、发展的必要条件。但在乌鲁木齐机场水汽条件达到一定程度时，即使机场上空没有逆温层，随着夜间降温乌鲁木齐机场仍会出现冻雾天气。
Using the conventional upper-air and surface data, FNL 1？ × 1？ reanalysis data, ground meteorological automatic station data and microwave radiometer data, the causes of the intermittent freezing fog weather after a snowfall at Urumqi International Airport from December 30, 2023 to January 2, 2024 were analyzed. It was found that: (1) This intermittent freezing fog weather process occurred under the background of the weather circulation with westerly airflow or warm ridge at 500 hPa and 700 hPa, combined with relatively strong warm advection at 850 hPa. (2) The change of surface temperature is one of the important reasons for the intermittency of the freezing fog weather at Urumqi Airport from December 30 to January 2. The decrease in temperature and the shift of surface wind to northerly are both conducive to the maintenance and development of the freezing fog at Urumqi Airport. (3) Affected by the eastward movement of the northern branch trough in the early stage, there was a light snow weather process in most of northern Xinjiang and the Tianshan mountainous area, which provided a good supplement of water vapor for the intermittent freezing fog weather. (4) Stable stratification is a necessary condition for the maintenance and development of freezing fog. However, when the water vapor condition at Urumqi Airport reaches a certain level, even if there is no inversion layer over the airport, freezing fog weather will still occur at Urumqi Airport with the temperature drop at night.