一次北极地区低云转化为海雾的观测研究  

An Observational Study of the Transition of Low Cloud into Sea Fog in the Arctic

作　　者：焦瀚 沈辉[3] 衣立[1,2] 张苏平 王晓宇 刘一林[2] Jiao Han;Shen Hui;Yi Li;Zhang Suping;Wang Xiaoyu;Liu Yilin(Frontiers Science Center for Deep Ocean Multispheres and Earth System,Ocean University of China,Qingdao 266100,China;College of Oceanic and Atmospheric Sciences,Ocean University of China,Qingdao 266100,China;National Marine Environmental Forecasting Center,Beijing 100081,China;Key Laboratory of Physical Oceanography,Ministry of Education,Ocean University of China,Qingdao 266100,China)

机构地区：[1]中国海洋大学深海圈层与地球系统前沿中心,山东青岛266100 [2]中国海洋大学海洋与大气学院,山东青岛266100 [3]国家海洋环境预报中心,北京100081 [4]中国海洋大学物理海洋教育部重点实验室,山东青岛266100

出　　处：《中国海洋大学学报（自然科学版）》2024年第7期12-21,共10页Periodical of Ocean University of China

基　　金：国家重点研究发展计划项目(2021YFC3101604,2019YFA0607000);国家自然科学基金项目(41975024)资助。

摘　　要：2016年8月11日,中国第七次北极科学考察在82.75°N,163.25°W附近观测到一次海雾过程。本文利用船载观测数据和浮冰站通量系统观测数据,结合再分析资料,对海雾的形成机理进行研究。结果表明,冷高压系统在冰面的加强,增强了下沉运动,使逆温层高度明显降低。伴随低云云底高度下降,冰面能见度下降至不足1 km。在低云下降过程中,冰面气象要素表现为增湿和降温的特征。冷平流和冰面的冷却作用导致气温下降,高低压之间的偏南气流将楚科奇海的水汽输送到密集浮冰区,为海雾提供了充足的水汽。冰面的升华和蒸发作用一方面对底层大气水汽增加有贡献,另一方面使冰面失去潜热导致冰面温度下降。Sea fog occurs frequently in the Arctic in summer.The low visibility caused by sea fog will pose a serious threat to the navigation safety of ships.Due to the lack of observations,there are few researches on the mechanism of Arctic sea fog.On August 11,2016,a sea fog process was observed at(82.75°N,163.25°W)during China′s seventh Arctic expedition.The formation mechanism of sea fog process is studied by using the data of shipborne observation and flux system observation combined with the data of reanalysis.The results indicate that the cold high-pressure system is intensified on the ice surface,enhancing the subsidence and causing a significant reduction in the height of the inversion layer.Along with the decrease in the height of the low cloud base,the visibility on the ice surface decreases to less than 1 km,reflecting the transformation of low cloud to sea fog.During the transition from low cloud to sea fog,the meteorological elements on the ice surface are characterised by humidification and cooling.The cooling effect of the cold advection and ice surface leads to a drop in temperature,and the south wind between high and low pressure transports water vapour from the Chukchi Sea to the dense ice areas,providing sufficient water vapour for sea fog.Sublimation and evaporation from the ice surface contributes to the increase in water vapour in the underlying atmosphere on the one hand,while on the other hand the loss of latent heat from the ice surface leads to a decrease in ice surface temperature.

关 键 词：北极 海雾 低云 观测 机理 平流 高压下沉 

分 类 号：P714.2[天文地球—海洋科学]