近日，中国极地研究中心Yongqing Cai团队研究了南大洋风暴后海洋混合层内的风锋相互作用：允许模拟的亚中尺度见解。该研究于2025年4月17日发表在《大气科学进展》杂志上。

南大洋的海洋混合层的特点是，由于冰融化引起的淡水流入的搅动，出现了许多锋面。这些锋面与风相互作用，调节混合层的演变，影响大气-海洋能量交换。然而，由于缺乏对海洋的三维观测，特别是速度的观测，风锋相互作用背后的潜在机制仍然模糊不清。为了解决这个问题，研究组通过使用全球亚中尺度允许模拟的子集ROAM_MIZ，研究了风暴期间混合层内锋面的动态，该子集侧重于威德尔海东北部地区。他们首先将ROAM_MIZ数据与滑翔机数据进行比较，以评估模型模拟的性能，发现ROAM_MYZ可以在很大程度上捕获混合层内的亚中尺度特征。

基于ROAM_MIZ子集的后续分析表明，在与风暴相关的大风期间，混合层内的横向密度梯度迅速降低。下锋风加速了这种下降，因为埃克曼浮力输送增强了锋面的不稳定性，主要由水平斜压分量主导。风暴过后，由于大尺度应变的锋面生成，锋面再次增强，风力较低。此外，非地转湍流导致相对涡度的改变，影响混合层内的不稳定性。这些发现为观测仪器的部署和后续分析提供了宝贵的指导，并加深了对南大洋海气相互作用的理解。

附：英文原文

Title: Wind-front interaction within oceanic mixed layer following a storm in the Southern Ocean: Insights from a submesoscale-permitting simulation

Author: Yongqing Cai, Ruibo Lei, Dake Chen, Lichuan Wu

Issue&Volume: 2025-04-17

Abstract: The oceanic mixed layer in the Southern Ocean is characterized by numerous fronts due to the stirring of freshwater influxes arising from ice-melting. These fronts interact with winds, modulating the evolution of mixed layer and affecting atmosphere-ocean energy exchanges. However, the underlying mechanism behind the wind-front interaction remains obscure due to lack of three-dimensional observations of the ocean, particularly velocities. To address this question, this study investigates the dynamic of fronts within the mixed layer during a storm by employing a subset of the global submesoscale-permitting simulation, ROAM_MIZ, which focuses on the Northeast Weddell Sea region. We first compare the ROAM_MIZ data to glider data to assess the performance of the model simulation, finding that the ROAM_MIZ can capture submesoscale features within mixed layer to a large degree. Subsequent analyses based on a subset of ROAM_MIZ show lateral density gradients within mixed layer decrease rapidly during high winds associated with the storm. Down-front winds accelerate this decrease as the Ekman buoyancy transport enhances the instability of the fronts, primary dominated by horizontally baroclinic components. After the storm, the fronts strengthen again with low winds due to the frontogenesis by larger scale strain. Moreover, the non-geostrophic turbulence induces modification of the relative vorticity, affecting the instability within mixed layer. These findings offer valuable guidance for the deployment of observational instruments and subsequent analysis, as well as deepen the understanding of air-sea interactions in the Southern Ocean.

DOI: 10.1007/s00376-025-4361-5

Source: http://www.iapjournals.ac.cn/aas/article/doi/10.1007/s00376-025-4361-5