特强寒潮背景下的北京大兴机场2023年12月持续性降雪天气分析

Analysis of Persistent Snowfall Weather in Beijing Daxing Airport in December 2023 under the Background of Extremely Strong Cold Wave

摘要: 本文基于北京大兴机场气象自动观测数据、例行实况报文数据、NCEP FNL全球大气再分析数据，对2023年12月13~15日大兴机场特强寒潮背景下的持续性降雪天气进行了诊断分析。结果表明：北京大兴机场持续性降雪天气是在特强寒潮背景下，槽前西南风急流带控制，高空水汽条件较好，为机场降雪提供了充足的水汽条件。低层850 hPa偏东气流从渤海输送的水汽集中在北京区域，降雪前期大兴机场长时间处于垂直上升运动的大气运动下，使得低层水汽不断抬升，降雪保持较长时间的持续。大兴机场始终位于低层暖平流控制中，冷平流冷却了低层偏南气流输送的水汽，对水汽凝结形成持续性降雪有重要贡献。另通过分析北京探空图不同高度层的温度、湿度和风速对大兴机场持续性降雪具有指示意义。

Abstract: Based on the automatic meteorological observation data, routine live message data and NCEP FNL global atmospheric reanalysis data of Beijing Daxing Airport, this paper diagnoses and analyzes the persistent snowfall weather under the background of extremely strong cold wave in Daxing Airport from December 13 to 15, 2023. The results show that the persistent snowfall weather at Beijing Daxing Airport is controlled by the southwesterly jet stream in front of the trough under the back-ground of extremely strong cold wave, and the high-altitude water vapor conditions are good, which provides sufficient water vapor conditions for the snowfall at the airport. The water vapor trans-ported by the low-level 850 hPa easterly airflow from the Bohai Sea is concentrated in the Beijing area. In the early stage of snowfall, Daxing Airport was under the atmospheric movement of vertical upward movement for a long time, which made the low-level water vapor continue to rise, making the snowfall maintain a long time. Daxing Airport is always located in the control of warm advection at the bottom layer. The cold advection cools the water vapor transported by the southerly airflow at the bottom layer, which makes an important contribution to the condensation of water vapor and the formation of persistent snowfall. In addition, the analysis of temperature, humidity and wind speed at different heights in Beijing sounding map has indicative significance for continuous snow-fall at Daxing Airport.