Hydrographic variability along the inner and mid-shelf region of the western Ross Sea obtained using instrumented seals
Hydrographic variability along the inner and mid-shelf region of the western Ross Sea obtained using instrumented seals
复制标题
使用仪器化海豹获得的罗斯海西部内陆架和中陆架区域的水文变化
DOI：
10.1016/j.pocean.2019.01.003
复制
发表时间：
2019
影响因子：
4.1
通讯作者：
Klinck, John M.
中科院分区：
文献类型：
--
作者：
Piñones, Andrea;Hofmann, Eileen E.;Costa, Daniel P.;Goetz, Kimberly;Burns, Jennifer M.;Roquet, Fabien;Dinniman, Michael S.;Klinck, John M.
利用2010-2012年夏末和次年春季期间部署在韦德尔海豹(Leptonychotes Wedellii)上的传感器获得的温度和盐度测量结果，描述了罗斯海西部水文条件的时空变异性，特别侧重于维多利亚陆地和麦克默多海峡附近的内陆架区域。为海豹长期滞留的区域绘制的潜在温-盐度图显示，大陆架上有四个水团：修正环极深水、南极表层水、大陆架水和修正大陆架水。潜势密度和浮力频率的深度-时间分布表明，随着夏季条件向秋季/冬季条件的转变，上层水柱层结受到侵蚀。与这一转变相关的年内和年际变化与风速有关。上层水柱密度的变化与跨陆架风速呈正相关>；5.5 m S−1，滞后3-4 日。由于每年不同的层结程度，需要一定范围的风速来侵蚀密度结构。风混合势与层结(韦德伯恩数)的比较表明，2012年天气尺度的风速分别为5.5 m和6.5 m S−1，以侵蚀罗斯岛和维多利亚陆地地区的夏季层结。2010年和2011年需要更强的风(>；8.5 m S−1)。夏季累积总热量的年际变化(约20%)与开阔水域的持续时间有关，最大热量出现在2012年，其特点是夏季海冰最小值比其他年份更强，mCDW对陆架中部和外部地区的影响相对较大。由于深冬对流的影响，热量在4月中旬以后丧失，并在冬季降至最低。从海豹测量中获得的对罗斯海西部内陆架区域水文变化的定量分析为评估未来的变化提供了基线。
Temperature and salinity measurements obtained from sensors deployed on Weddell seals (Leptonychotes weddellii) between late austral summer and the following spring for 2010–2012 were used to describe the temporal and spatial variability of hydrographic conditions in the western Ross Sea, with particular emphasis on the inner-shelf region off Victoria Land and McMurdo Sound. Potential temperature-salinity diagrams constructed for regions where the seals remained for extended periods showed four water masses on the continental shelf: Modified Circumpolar Deep Water, Antarctic Surface Water, Shelf Water and Modified Shelf Water. Depth-time distributions of potential density and buoyancy frequency showed the erosion of the upper water column stratification associated with the transition from summer to fall/winter conditions. The within-year and interannual variability associated with this transition was related to wind speed. Changes in upper water column density were positively correlated with cross-shelf wind speeds >5.5 m s−1with a 3–4 day lag. A range of wind speeds was required to erode the density structure because of different levels of stratification in each year. A comparison of wind mixing potential versus stratification (Wedderburn number) showed that synoptic scale wind events during 2012 with speeds of 5.5 and 6.5 m s−1were needed to erode the summer stratification for Ross Island and Victoria Land regions, respectively. Stronger winds (>8.5 m s−1) were required during 2010 and 2011. The interannual variability in total heat content accumulated during summer (about 20%) was related to the duration of open water, with the largest heat content occurring in 2012, which was characterized by a summer sea ice minimum stronger than other years and relatively higher mCDW influence over the mid and outer-shelf regions. The heat content was lost after mid-April and reached a minimum in winter as a result of deep winter convection. The quantitative analysis of hydrographic variability of the inner-shelf region of the western Ross Sea obtained from the seal-derived measurements provides a baseline for assessing future changes.