南极普里兹湾海域初冬冰间湖时空变化及上层水体热盐结构演化研究

发布时间：2018-07-05 06:54

本文选题：普里兹湾 + 冰间湖　；参考：《上海海洋大学》2015年硕士论文

【摘要】：本文利用德国不莱梅大学发布的2008-2011逐日海冰密集度数据与美国冰雪中心提供的2012年逐日海冰密集度数据,研究了南极普里兹湾初冬季冰间湖时空分布与变化规律,并结合再分析的风场资料,探讨了冰间湖的产生及影响因素;利用南极普里兹湾象海豹携带的CTD标记观测获得的2011-2012年初冬埃默里冰架前缘冰间湖海域温盐剖面,研究了海水结构演变及其与冰间湖发生和海冰形成的联系,主要研究内容如下:一、普里兹湾冬季冰间湖的形态特征和空间变化。从2008-2012年普里兹湾冬季每个月都会出现冰间湖,位置主要集中于埃默里冰架前缘海域(麦肯齐湾)与冰架东侧区域,以及达恩利角北部海域。埃默里冰架前缘冰间湖整体沿着冰架前缘方向呈带状分布,冰间湖西部与大陆相连,东部则沿着冰架前缘向东延伸,最北处可以达到68°S以北,在冰架西部前缘存在的时间长于东部前缘;埃默里冰架东侧冰间湖所在的位置靠近大陆边缘冰架,东西范围不超过1个经度,南北范围不超过1个纬度;达恩利角冰间湖的空间形状不固定,最大范围向南与大陆接壤,向北可以达到66.5°S,东部边缘可以达到71.5°E,西部则可以延伸到68°E。二、普里兹湾冬季冰间湖面积随时间变化及其影响因素。2008-2012年,冬季冷却和结冰作用,每年自3月下旬普里兹海域开始出现海冰,并逐步扩展,冰间湖出现在近岸区域;4月以后,该海域海冰进一步发展,一方面形成沿岸固定冰,这是的冰间湖面积随时间变化逐年差异较大。5-8月,该海域冰间湖的面积也有较大的年际变化,但是总面积月度变化幅度减少。该海域出现冰间湖累计平均面积为1.32×106km2,其中冰间湖面积达到最大值主要在4月初。离岸风风速与冰间湖面积具有良好的相关关系,当离岸风增大时,面积增大,风速减小时,面积减小;三、普里兹湾海域冬季上层水体特征及结构演化过程。可分为三个阶段:海水温度从层化到均匀的阶段,次表层海水仍维持暖水特征,随着表层海水的冷却,垂直对流混合加强,次表层暖水逐渐消失;海水盐度从层化到上下均匀的阶段,海水结冰析盐过程使上层海水盐度增加,垂直对流混合增强,上下层盐度达到均匀;冷却结冰持续的阶段,海水盐度继续增加,海水温度接近冰点。四、普里兹湾冰间湖区冬季海洋热含量变化及海气交换。通过普里兹湾冰间湖区海豹CTD标记观测获得的温盐剖面数据估算得到2011年水体结构演化的三个阶段海洋热含量变化率分别是-90.93W?m-2、-82.20 W?m-2、-43.44 W?m-2,2012年第3阶段的平均热含量变化率为-47.40 W?m-2;由海水盐度增加估算的2011年三个阶段海冰形成速率分别是5.4 cm?d-1、4.9 cm?d-1、2.5 cm?d-1,而2012年第3阶段平均为5.14 cm?d-1;与欧洲气象中心再分析数据产品(ERA-Interim)风速、2m气温、热通量资料相关分析,得到海冰形成速率与离岸风风速、显热通量、潜热通量呈正相关,与2m气温呈负相关。
[Abstract]:In this paper, the temporal and spatial distribution and variation of interglacial lakes in Prydz Bay, Antarctica, in the early winter of Prydz Bay, Antarctica, are studied using the daily sea ice intensity data published by Bremen University, Germany, and the daily sea ice concentration data provided by the American Ice and Snow Center in 2012. Combined with the reanalyzed wind field data, the generation and influencing factors of the interglacial lake are discussed, and the temperature and salt profile of the interglacial lake in the front edge of the Emory Ice Shelf in the early winter of 2011-2012 is obtained by using CTD markers carried by the elephant seals in Prydz Bay, Antarctica. The evolution of sea water structure and its relationship with the occurrence of interglacial lakes and the formation of sea ice are studied. The main contents are as follows: 1. The morphological characteristics and spatial changes of the interglacial lakes in Prydz Bay in winter. From 2008 to 2012, Interglacial Lake appeared in the Prydz Bay every month in the winter, mainly located in the Mackenzie Bay and the east of the ice shelf, as well as in the northern waters of Cape Darnley. The interglacial lake in the front edge of the Emory ice shelf is distributed in a zonal pattern along the front edge of the ice shelf. The western part of the interglacial lake is connected to the continent, while the eastern part extends eastward along the front edge of the ice shelf, and the northernmost part can reach to the north of 68 掳S. The eastern edge of the Emory ice shelf is located near the continental ice shelf, and the east-west range does not exceed 1 longitude, and the north and south ranges do not exceed 1 latitude, and the eastern edge of the ice shelf is longer than that of the eastern edge of the ice shelf, and the position of the eastern edge of the ice shelf is close to the continental ice shelf. The spatial shape of Cape Darnley's interglacial lake is not fixed. The maximum range of the lake is 66.5 掳S in the north, 71.5 掳E in the eastern edge and 68 掳E in the west. Secondly, the winter interglacial lake area of Prydz Bay changes with time and its influencing factors. From 2008 to 2012, the winter cooling and ice formation began to appear in the Prydz sea area in late March and gradually expanded, and the interglacial lake appeared in the coastal area; after April, The further development of sea ice in this sea area, on the one hand, formed the fixed ice along the coast, which is that the area of the interglacial lake varies greatly with time year by year. The area of the interglacial lake in this sea area also has great interannual variation, but the monthly variation of the total area decreases. The accumulative average area of interglacial lake in this area is 1.32 脳 10 ~ (6) km ~ (2), in which the maximum area of interglacial lake is mainly in early April. There is a good correlation between the wind speed of offshore wind and the area of interglacial lake. When the offshore wind increases, the area increases, the wind speed decreases a little, and the area decreases. Thirdly, the characteristics and structural evolution of the upper layer in the Prydz Bay in winter. It can be divided into three stages: from stratification to homogenization, the subsurface seawater still maintains the warm water characteristic, with the cooling of the surface water, the vertical convection mixing is strengthened, the subsurface warm water gradually disappears; During the process of sea water freezing and salt evolution, the salinity of the upper sea water increases, the vertical convection increases, and the salinity of the upper and lower layers reaches uniformity. The sea temperature is close to freezing point. Fourth, the variation of ocean heat content and sea-air exchange in the Interglacial Lake area of Prydz Bay in winter. Based on the temperature and salt profile data of seal CTD in the Interglacial Lake region of Prydz Bay, the variation rates of marine heat content in the three stages of water structure evolution in 2011 are -90.93 Wm ~ (-2) -82.20 W ~ (-2) ~ (-2) -43.44 W ~ (-1) ~ (-2) and the mean heat content change in the third stage of 2012, respectively. The rate of sea ice formation is -47.40 W / m ~ (-2). The estimated rate of sea ice formation in the three stages of 2011 is 5.4 cm ~ (-1) ~ (-4) cm ~ (-1) ~ (-) ~ (4.9) cm ~ (-1) ~ (-1) ~ 2.5 cm ~ (-1) ~ (-1), compared with the average of 5.14 cm ~ (-1) in the third stage of 2012, and the wind speed 2m temperature of the ERA-Interim reanalysis data product is calculated by the European Centre of Meteorology (ECM). The correlation analysis of heat flux data shows that the sea ice formation rate is positively correlated with the offshore wind speed, sensible heat flux and latent heat flux, and negatively correlated with 2m air temperature.
【学位授予单位】：上海海洋大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P731.15

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