Hydrography in the Gerlache and Bismarck straits is described based on data collected in Januaries of 2015 and 2017, during austral summer. These straits are in the northern Antarctic Peninsula (NAP) continental shelf. In the study area, temperature in the surface mixed layer during January 2017 was warmer than recorded in other years, contemporaneous with an extreme decrease in Antarctic sea ice extent at the end of 2016. This was probably caused by warm water advected from the north into Gerlache Strait, a consequence of northeasterly surface winds over the NAP, forced by a Southern Annular Mode (SAM) negative phase. Optimum multiparameter analysis indicated that relatively warm, salty and low-oxygenated modified Circumpolar Deep Water (mCDW) intrudes over the NAP continental shelf and dominates the Bismarck Strait, where it enters the Gerlache Strait, especially through its southern extremity. The mCDW mixes with relatively cold, fresh and recently ventilated modified High Salinity Shelf Water (mHSSW), producing temporal variations in water proportions. HSSW forms in the Weddell Sea and is advected southward along the deep basins of the Bransfield Strait, entering as bottom water into Gerlache Strait via its northern limit. There were two fronts in Gerlache Strait during both summers. First was a surface thermal front in the mixed layer represented by the 1 °C isotherm (~64.5°S), which separated colder waters toward Bismarck Strait. Second was a sub-pycnocline front, represented by the 0.4 °C and 220 μmol kg⁻¹ dissolved oxygen contours below ~100 dbar, which separated mCDW toward Bismarck Strait from mHSSW on the northern side of the strait. This frontal position varies as a consequence of temporal variations in source water fractions. Moreover, changes in Ekman transport, forced by enhanced westerly winds associated with a SAM positive phase, appeared responsible for a major fraction of mCDW in Gerlache Strait during 2015 relative to 2017. The spatiotemporal variability of source water mixing in the water column structure of the Gerlache Strait might have implications for local biological and chemical cycles, and for regional climate feedbacks, because warm mCDW accelerates glacier retreat in the western Antarctic Peninsula.

根据南方夏季2015年和2017年1月收集的数据描述了Gerlache和Bismarck海峡的水文学。这些海峡位于南极半岛北部大陆架。在研究区域，2017年1月的地表混合层温度高于其他年份的记录，与此同时，南极海冰面积在2016年底急剧下降。这可能是由于从北向太平洋输送的温水造成的。 Gerlache海峡，是由南环空模式（SAM）负相强迫在NAP上进行东北风的结果。最佳多参数分析表明，相对温暖，咸和低氧的改良环极深水（mCDW）侵入了NAP大陆架，并主导了Bi斯麦海峡，它进入Gerlache海峡的地方，特别是通过其南端。mCDW与相对较冷，新鲜和最近通风的改良高盐度搁板水（mHSSW）混合，导致水比例随时间变化。HSSW形成于韦德尔海中，并沿布兰斯菲尔德海峡的深海盆地向南平移，作为底水通过其北端进入杰拉什海峡。在两个夏天期间，盖拉奇海峡都有两条战线。首先是在以1°C等温线（〜64.5°S）表示的混合层中的表面热锋，它将较冷的水分离到toward斯麦海峡。第二个是亚次青霉素前沿，以0.4°C和220μmolkg为代表 新鲜和最近通风的改良高盐度搁板水（mHSSW），导致水比例随时间变化。HSSW形成于韦德尔海中，并沿布兰斯菲尔德海峡的深海盆地向南平移，作为底水通过其北端进入杰拉什海峡。在两个夏天期间，盖拉奇海峡都有两条战线。首先是在以1°C等温线（〜64.5°S）表示的混合层中的表面热锋，它将较冷的水分离到toward斯麦海峡。第二个是亚次青霉素前沿，以0.4°C和220μmolkg为代表 新鲜和最近通风的改良高盐度搁板水（mHSSW），导致水比例随时间变化。HSSW形成于韦德尔海中，并沿布兰斯菲尔德海峡的深海盆地向南平移，作为底水通过其北端进入杰拉什海峡。在两个夏天期间，盖拉奇海峡都有两条战线。首先是在以1°C等温线（〜64.5°S）表示的混合层中的表面热锋，它将较冷的水分离到toward斯麦海峡。第二个是亚次青霉素前沿，代表0.4°C和220μmolkg 在两个夏天期间，盖拉奇海峡都有两条战线。首先是在以1°C等温线（〜64.5°S）表示的混合层中的表面热锋，它将较冷的水分离到toward斯麦海峡。第二个是亚次青霉素前沿，以0.4°C和220μmolkg为代表 在两个夏天期间，盖拉奇海峡都有两条战线。首先是在以1°C等温线（〜64.5°S）表示的混合层中的表面热锋，它将较冷的水分离到toward斯麦海峡。第二个是亚次青霉素前沿，以0.4°C和220μmolkg为代表^-1溶解氧的等值线在〜100 dbar以下，使朝向CD斯麦海峡的mCDW与位于海峡北侧的mHSSW分开。由于水源部分的时间变化，该正面位置也会变化。而且，与SAM正相相关的强西风推动了Ekman运移的变化，这在2015年相对于2017年是Gerlache海峡mCDW的主要部分。水源水混合在水柱结构中的时空变化Gerlache海峡可能会对当地的生物和化学循环以及区域气候反馈产生影响，因为温暖的mCDW加速了南极半岛西部的冰川退缩。