Two‐dimensional numerical simulations of Arctic leads: Plume penetration height
Two‐dimensional numerical simulations of Arctic leads: Plume penetration height
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北极铅的二维数值模拟：羽流穿透高度
DOI：
10.1029/2000jc000495
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发表时间：
2003
影响因子：
--
通讯作者：
S. Krueger
中科院分区：
文献类型：
--
作者：
M. Zulauf;S. Krueger
[1] 在北极冬季，由于海面和大气之间的极端温差，铅可能成为大气中热量和水蒸气的重要来源。然而，由于它们的规模相对较小，浮冰中的这些开口无法通过大型模型明确解析。在本研究中，采用二维云解析模型来检查在引线附近形成的对流羽流的发展。关于铅的两个重要考虑因素是温水表面上增强的表面通量以及由此产生的羽流穿透的高度，这代表直接受这些增强的通量影响的大气深度。研究了羽流高度对环境风速、方向和引线宽度的依赖性。与早期大涡模拟结果的比较通常显示出良好的一致性，而与羽流高度的简单解析表达式的比较显示，对于没有交叉导程大规模流动的情况，一致性良好，而对于具有显着交叉导程风的情况，一致性较差。进行敏感性实验来衡量交互微物理和辐射过程的影响。当这些过程包含在模拟中时，羽流深度比基线情况增加了 20%，这与早期的一维结果基本一致。最后发现，通过将表面浮力通量推广到包括潜在通量和辐射通量，羽流高度的解析表达式可以成功地应用于没有大范围横向风的情况。
[1] During the Arctic winter, leads can be a significant source of heat and water vapor for the atmosphere due to the extreme temperature differences between the sea surface and the atmosphere. Because of their relatively small scales, however, these openings in the pack ice cannot be explicitly resolved by large-scale models. In the present study, a two-dimensional cloud-resolving model is employed to examine the development of the convective plumes that can form in the vicinity of leads. Two important considerations with respect to leads are the enhanced surface fluxes over the warm water surface and the height to which the resulting plumes penetrate, which represents the depth of the atmosphere that is directly affected by these enhanced fluxes. The dependence of plume height on ambient wind speed, orientation, and lead width is investigated. Comparisons to earlier large-eddy simulation results generally show good agreement, while comparisons with simple analytical expressions for plume height show good agreement for cases with no cross-lead large-scale flow and poor agreement for cases with significant cross-lead winds. Sensitivity experiments are run to gauge the impacts of interactive microphysical and radiative processes. When these processes are included in the simulations, plume depths increase up to 20% over the baseline case, which is in general agreement with earlier one-dimensional results. Finally, it was found that by generalizing the surface buoyancy flux to include latent and radiative fluxes, the analytical expression for plume height could be successfully applied to the case where there is no large-scale cross-lead wind.