Data used in "The daily-resolved Southern Ocean mixed layer: regional contrasts assessed using glider observations"

These are the data used in the analysis and creation of figures in du Plessis et al. 2022: <em>The daily-resolved Southern Ocean mixed layer: regional contrasts assessed using glider observations</em> in support of open-code, transparency, and repeatability. Abstract: Water mass transformation in the Southern Ocean is vital for driving the large-scale overturning circulation, which transports heat from the surface to the ocean interior. Using profiling gliders, this study investigates the role of summertime buoyancy forcing and wind-driven processes on the intraseasonal (1-10 days) mixed layer thermohaline variability in three Southern Ocean regions southwest of Africa important for water mass transformation - the Subantarctic Zone (SAZ), Polar Frontal Zone (PFZ) and Marginal Ice Zone (MIZ). At intraseasonal time scales, heat flux was shown as the main driver of buoyancy gain in all regions. In the SAZ and MIZ, shallow mixed layers and strong stratification enhanced mixed layer buoyancy gain by trapping incoming heat, while buoyancy loss resulted primarily from the entrainment of cold, salty water from below. In the PFZ, rapid mixing linked to Southern Ocean storms set persistently deep mixed layers and suppressed mixed layer intraseasonal (1-10 days) thermohaline variability. In the polar regions, lateral stirring of meltwater from seasonal sea-ice melt dominated daily mixed layer salinity variability. We propose that these meltwater fronts are advected to the PFZ during late summer, indicating the potential for seasonal sea-ice freshwater to impact a region where the upwelling limb of overturning circulation reaches the surface. This study reveals a regional dependence of how the mixed layer thermohaline properties respond to small spatio-temporal processes, emphasizing the importance of surface forcing occurring between 1-10 days on the mixed layer water mass transformation in the Southern Ocean. <strong>Related code:</strong> The accompanying code can be found at: http://doi.org/10.5281/zenodo.5076119. Navigate to github.com/marcelduplessis/duplessis-2021-SO-thermohaline for the latest version本数据集为du Plessis等人2022年发表的论文《逐日分辨率南大洋混合层：利用滑翔机观测评估区域差异》（The daily-resolved Southern Ocean mixed layer: regional contrasts assessed using glider observations）中用于数据分析与图表绘制的全部配套数据，旨在支持开源代码、研究透明化与结果可复现。 **摘要**：南大洋水团变性是驱动大尺度经向翻转环流的核心环节，该环流可将热量从海洋表层输送至海洋内部。本研究利用剖面滑翔机（profiling gliders），针对非洲西南海域三个对水团变性至关重要的南大洋区域——亚南极区（Subantarctic Zone, SAZ）、极锋区（Polar Frontal Zone, PFZ）与海冰边缘区（Marginal Ice Zone, MIZ），探讨了夏季浮力强迫与风驱动过程对季节内（1~10天）尺度混合层温盐变率的调控作用。在季节内时间尺度上，热通量是所有区域浮力增加的主要驱动因子。在亚南极区与海冰边缘区，浅薄混合层与强层结通过捕获入射热量强化了混合层的浮力增加；而浮力损失则主要源于从下层夹卷而来的冷高盐水体。在极锋区，与南大洋风暴相关的快速混合维持了持续深厚的混合层，并抑制了混合层的季节内（1~10天）温盐变率。在极地海域，季节性海冰融化产生的融水的侧向搅拌主导了混合层每日的盐度变率。本研究提出，这些融水锋面会在夏末被平流输送至极锋区，这表明季节性海冰淡水有可能对经向翻转环流上升支抵达表层的区域产生影响。本研究揭示了混合层温盐特性对中小时空尺度过程的响应存在区域依赖性，强调了1~10天尺度的表层强迫对南大洋混合层水团变性的重要性。 **相关代码**：配套代码可通过以下链接获取：http://doi.org/10.5281/zenodo.5076119。如需获取最新版本，请访问github.com/marcelduplessis/duplessis-2021-SO-thermohaline。