Processes contributing to cloud dissipation and formation events on the North Slope of Alaska
Processes contributing to cloud dissipation and formation events on the North Slope of Alaska
复制标题
促成阿拉斯加北坡云消散和形成事件的过程
DOI：
10.5194/acp-21-4149-2021
复制
发表时间：
2021
影响因子：
6.3
通讯作者：
H. Telg
中科院分区：
文献类型：
--
作者：
J. Sedlar;A. Igel;H. Telg
抽象。高纬度地区的晴空周期对地表能量收支和低层大气层结有着深远的影响;然而，
对导致低层云消散和形成事件的大气过程的理解是有限的。一种识别清晰
阿拉斯加州Utqiagivik（原巴罗）的5年期（2014-2018年）。一套遥感和现场
分析了高纬度天文台的测量结果;我们重点比较和对比低层（以下）期间的大气特性
2公里）的云消散和形成事件，以了解控制晴空时段的过程。激光雷达垂直剖面图
后向散射表明，低层大气中的气溶胶存在在晴朗条件下相对不变，
表明，稀疏的气溶胶并不经常是阿拉斯加北坡云消散的原因。此外，气象分析
表明两个活跃的过程正在进行，似乎支持形成低云后，晴朗的天空时期：即，水平平流，
在冬季和早春占主导地位，和静止的空气质量修改，这是在夏季占主导地位。在夏季，占主导地位的
云的形成模式是在近地面形成低云或雾层。这种低云的形成主要是由相对静止的天气条件下的空气质量修改。近地面气溶胶粒子浓度的变化的一个因素2左右的夏季形成事件。热力学调节和静止大气条件下气溶胶的存在增加被假设为雾形成的重要机制。
Abstract. Clear-sky periods across the high latitudes have profound impacts on the surface energy budget and lower atmospheric stratification; however an
understanding of the atmospheric processes leading to low-level cloud dissipation and formation events is limited. A method to identify clear
periods at Utqiaġvik (formerly Barrow), Alaska, during a 5-year period (2014–2018) is developed. A suite of remote sensing and in situ
measurements from the high-latitude observatory are analyzed; we focus on comparing and contrasting atmospheric properties during low-level (below
2 km ) cloud dissipation and formation events to understand the processes controlling clear-sky periods. Vertical profiles of lidar
backscatter suggest that aerosol presence across the lower atmosphere is relatively invariant during the periods bookending clear conditions, which
suggests that a sparsity of aerosol is not frequently a cause for cloud dissipation on the North Slope of Alaska. Further, meteorological analysis
indicates two active processes ongoing that appear to support the formation of low clouds after a clear-sky period: namely, horizontal advection,
which was dominant in winter and early spring, and quiescent air mass modification, which was dominant in the summer. During summer, the dominant
mode of cloud formation is a low cloud or fog layer developing near the surface. This low cloud formation is driven largely by air mass modification under relatively quiescent synoptic conditions. Near-surface aerosol particles concentrations changed by a factor of 2 around summer formation events. Thermodynamic adjustment and increased aerosol presence under quiescent atmospheric conditions are hypothesized as important mechanisms for fog formation.
登录
查看更多内容
了解层状混合相云中云液和冰之间相分配的快速变化：北极案例研究
影响因子：
3.2
作者：
Kalesse;G. de Boer;A. Solomon;M. Ahlgrimm;D. Zhang;M. Shupe;E. Luke;A. Protat
通讯作者：
A. Protat
影响因子：
4.6
作者：
J. Sedlar;M. Tjernström;T. Mauritsen;M. Shupe;I. Brooks;P. Persson;C. Birch;C. Leck;A. Sirevaag;M. Nicolaus;M. Nicolaus
通讯作者：
J. Sedlar;M. Tjernström;T. Mauritsen;M. Shupe;I. Brooks;P. Persson;C. Birch;C. Leck;A. Sirevaag;M. Nicolaus;M. Nicolaus
影响因子：
6.3
作者：
Shupe, M. D.;Persson, P. O. G.;Leck, C.
通讯作者：
Leck, C.
影响因子：
6.3
作者：
Mauritsen, T.;Sedlar, J.;Swietlicki, E.
通讯作者：
Swietlicki, E.
北极夏季气团转变、地表逆温和地表能量收支
影响因子：
4.9
作者：
Tjernström M
通讯作者：
Tjernström M