Thermohaline variability and Antarctic bottom water formation at the Ross Sea shelf break
Thermohaline variability and Antarctic bottom water formation at the Ross Sea shelf break
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DOI：
10.1016/j.dsr.2011.07.002
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发表时间：
2011-10-01
影响因子：
2.4
通讯作者：
Padman, Laurie
中科院分区：
文献类型：
--
作者：
Budillon, Giorgio;Castagno, Pasquale;Padman, Laurie
我们使用1995至2006年间在南极罗斯海收集的水文和测流仪数据来描述与南极底层水(AABW)产生有关的水团的时空变化。在该区域已知的两个高密度陆架水流出区收集了数据；Drygalski海槽(DT)和Glomar-Challenger海槽(GCT)。陆架断裂近岸致密的陆架水以DT的高盐度陆架水(HSSW)和GCT的冰架水(ISW)为主。DT北部的HSSW以11年的0.06次增温为主，GCT北部的ISW以8年的0.04次和11年的0.04度的增暖为主，以2001/02年南半球夏季的快速增温为主。将温暖的绕极深水(CDW)与陆架水分开的南极坡锋在GCT附近比DT附近更稳定，CDW和混合产物在DT外陆架上存在，而在GCT外陆架上不存在。这两个地点的源水和混合过程不同，导致罗斯海中西部产生了具有不同温盐特征的AABW。两个槽区陆架断裂100公里范围内长期停泊的水文和海流的多年时间序列证实了密集陆架水的年际信号，揭示了水团性质的季节循环。在DT附近，HSSW盐度在3/4月出现最大值，在9/10月出现最小值。GCT的ISW在3/4月最热，8-10月最凉。系泊数据还显示出与潮汐和其他过程相关的显著高频变化。对GCT以西大陆坡密水级联进行采样的近底部系泊传感器的小波分析显示，冷密水的间歇性能量脉冲的周期从类似于32h到类似于5天。(C)2011爱思唯尔有限公司。保留所有权利。
We use hydrological and current meter data collected in the Ross Sea, Antarctica between 1995 and 2006 to describe the spatial and temporal variability of water masses involved in the production of Antarctic Bottom Water (AABW). Data were collected in two regions of known outflows of dense shelf water in this region; the Drygalski Trough (DT) and the Glomar-Challenger Trough (GCT). Dense shelf water just inshore of the shelf break is dominated by High Salinity Shelf Water (HSSW) in the DT and Ice Shelf Water (ISW) in the GCT. The HSSW in the northern DT freshened by similar to 0.06 in 11 y, while the ISW in the northern GCT freshened by similar to 0.04 in 8 y and warmed by similar to 0.04 degrees C in 11 y, dominated by a rapid warming during austral summer 2001/02. The Antarctic Slope Front separating the warm Circumpolar Deep Water (CDW) from the shelf waters is more stable near GCT than near DT, with CDW and mixing products being found on the outer DT shelf but not on the outer GCT shelf. The different source waters and mixing processes at the two sites lead to production of AABW with different thermohaline characteristics in the central and western Ross Sea. Multi-year time series of hydrography and currents at long-term moorings within 100 km of the shelf break in both troughs confirm the interannual signals in the dense shelf water and reveal the seasonal cycle of water mass properties. Near the DT the HSSW salinities experienced maxima in March/April and minima in September/October. The ISW in the GCT is warmest in March/April and coolest between August and October. Mooring data also demonstrate significant high-frequency variability associated with tides and other processes. Wavelet analysis of near-bottom moored sensors sampling the dense water cascade over the continental slope west of the GCT shows intermittent energetic pulses of cold, dense water with periods from similar to 32 h to similar to 5 days. (C) 2011 Elsevier Ltd. All rights reserved.