南极半岛周边海域水团及水交换的研究

Study on the properties and exchanges of water masses in the region of Antarctic Peninsula

利用中国第34次南极考察于2018年1–2月在南极半岛周边海域获得的温盐、海流现场观测数据,分析了调查区域主要水团及水交换特征。结果表明,观测区域内主要存在南极表层水、绕极深层水、暖深层水、南极底层水、布兰斯菲尔德海峡底层水。威德尔海的暖深层水、威德尔海深层水通过南奥克尼海台东侧的奥克尼通道、布鲁斯通道和南奥克尼海台西侧的埃斯佩里兹通道进入斯科舍海,其中奥克尼通道的深层海流最强,流速最大可达0.25 m/s,密度较大的威德尔海深层水可以通过此通道进入斯科舍海;布鲁斯通道海流流速约为0.13 m/s,通过此通道的暖深层水位势温度较高;埃斯佩里兹通道海流流速约为0.10 m/s,通过此通道的暖深层水位势温度最低,威德尔海深层水密度最小。在南奥克尼海台东西两侧均观测到南向和北向的海流,但整体上来看,向北的海流和水交换更强。水体进入斯科舍海后,沿着南斯科舍海岭的北侧向西北方向流动,流速约为0.21 m/s。德雷克海峡中的南极绕极流仅有一部分向东进入斯科舍海南部海域,且受到向西流动的暖深层水、威德尔海深层水的影响,斯科舍海南部海域的绕极深层水明显比德雷克海峡中绕极深层水的高温高盐性质弱;受到南极绕极流的影响,南斯科舍海岭北侧的威德尔海深层水比南侧暖。南斯科舍海岭上的水体可能受到北侧绕极深层水、暖深层水,西侧陆架水,东侧冬季水的影响,因此海岭上水体结构较为复杂。

Based on the 34 th Chinese Antarctic scientific expedition'Xiangyanghong 01'cruise around the Antarctic Peninsula from January to February 2018,the properties and exchanges of water masses in the region of Antarctic Peninsula were analyzed.The main water masses are Antarctic Surface Water,Circumpolar Deep Water,Warm Deep Water,Antarctic Bottom Water,Bransfield Srait Bottom Water.Weddell Sea Warm Deep Water and Weddell Sea Deep Water flow into Scotia Sea through the Orkney Passage,the Bruce Passage on the east of the South Orkney Plateau and the Hesperides Gap on the west of the South Orkney Plateau.Among them,the deepest current velocity is 0.25 m/s in Orkney Passage,which allow denser Weddell Sea Deep Water to flow to Scotia Sea;the current velocity is 0.13 m/s in Bruce Passage,which allow warmer Warm Deep Water flows and the temperature of Warm Deep Water passing through this gap is the lowest,and the current velocity is 0.10 m/s in Hesperides Gap,only colder Warm Deep Water and lighter Weddell Sea Deep Water can pass.Southward currents and northward currents were observed on both sides of the South Orkney Plateau,but northward currents and water exchange are stronger.Water flow westward along the north side of the South Scotia Ridge after entering the Scotia Sea through the Passages on both sides of the South Orkney Plateau,with a velocity of 0.21 m/s.A branch of Antarctic Circumpolar Current in Drake Passage flow eastward to Scotia Sea,and influenced by Warm Deep Water and Weddell Sea Deep Water flowing westward,Circumpolar Deep Water in the Scotia Sea is obviously weaker than that in the Drake Passage.Affected by the eastward Antarctic Circumpolar Current,Weddell Sea Deep Water on the north side of the South Scotia Ridge is warmer than that on the south side.The water on the South Scotia Ridge may be affected by the Circumpolar Deep Water and Warm Deep Water in the north,Shelf Water in the West and Winter Water in the east,so the structure of the water on the South Scotia Ridge is much complex.