贵阳龙洞堡机场霜天气预报技术研究

Research on Frost Weather Forecast Technology for Guiyang Longdongbao Airport

摘要: 利用2008~2023年ECMWF ERA5再分析资料及贵阳机场自观数据、机场天气报告及观测纪要栏数据分析了贵阳机场霜天气的环流形势、时间特征及气象因子的阈值，以期提高贵阳机场霜天气的预报预警能力。结果表明：1) 贵阳机场霜日年平均为2.8天，主要发生在11月~次年2月；2) 霜日平均环流形势：500 hPa、700 hPa均为弱脊控制，850 hPa为弱高压控制，地面为弱均压场控制；3) 夜间辐射降温明显，04~08时温度及露点温度均在0℃以下，07时降至最低；霜前日平均最高温为10.6℃，霜日平均最低温为−2.8℃，平均温差为13.4℃；霜日03时后相对湿度大于90%；出霜时风向多为风向不定(占比32.3%)或静风(占比24.5%)、风速多小于2 m/s (87.9%)、天空状况多为晴到少云；4) 霜出现时常伴随视程障碍现象，其中轻雾最多(54.5%)，其次为冻雾(29.5%)；主导能见度和跑道视程整体呈先降低后抬升的趋势，冻雾伴霜日雾一般较浓，主导能见度和跑道视程较低，可低至50 m，持续时间较久；5) 出霜时平均海平面气压范围为1024~1026 hPa。

Abstract: Using ECMWF ERA5 reanalysis data from 2008 to 2023, as well as observational data from Guiyang Airport, airport weather reports, and observation summary columns, the circulation pattern, temporal characteristics, and meteorological factor thresholds of frost weather at Guiyang Airport were analyzed in order to improve the forecasting and early warning capabilities of frost weather at Guiyang Airport. The results show that: 1) The average frost days at Guiyang Airport are 2.8 days per year, mainly occurring from November to February of the following year; 2) The average circulation pattern of frost days: weak ridge control at 500 hPa and 700 hPa, weak high pressure control at 850 hPa, and weak mean pressure field control at the ground level; 3) During the night, the cooling effect from radiation is significant, with temperatures and dew points both dropping below 0°C between 04:00 and 08:00, reaching their lowest point at 07:00. The average maximum temperature prior to frost is 10.6°C, while the average minimum temperature on frost days is -2.8°C, resulting in an average temperature difference of 13.4°C. After 03:00 on frost days, the relative humidity generally exceeds 90%. At the time of frost occurrence, the wind direction is often variable (32.3% of the time) or calm (24.5%), with wind speeds mostly below 2 m/s (87.9%), and sky conditions are typically clear to partly cloudy; 4) Frost often accompanies visual impairment, with light fog being the most common (54.5%), followed by freezing fog (29.5%); The dominant visibility and runway visual range show an overall trend of first decreasing and then increasing. Frost fog with frost is generally thicker, and the dominant visibility and runway visual range are lower, up to 50 m, with a longer duration; 5) The average sea level pressure range during frost is 1024~1026 hPa.