Structure and Variability of the Antilles Current at 26.5°N
Structure and Variability of the Antilles Current at 26.5°N
复制标题
26.5°N安的列斯海流的结构和变化
DOI：
10.1029/2018jc014836
复制
发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Garzoli, Silvia L.
中科院分区：
文献类型：
--
作者：
Meinen, Christopher S.;Johns, William E.;Moat, Ben I.;Smith, Ryan H.;Johns, Elizabeth M.;Rayner, Darren;Frajka‐Williams, Eleanor;Garcia, Rigoberto F.;Garzoli, Silvia L.
来自五个不同系统的观测为2005-2015年期间北纬26.5°的安的列斯洋流的结构和变异性提供了一幅清晰的图景，该洋流是海洋通量收支的重要组成部分。分析包括三种直接测量技术(海流计、船载声学多普勒海流剖面仪和降压式声学多普勒海流剖面仪)和两种基于地转学的测量技术(电导率-温度-深度剖面仪和配备压力的反向回声测深仪)。结果表明，与基于地转的系统相比，直接系统产生的安的列斯海流运移估计更弱、变化更小。安的列斯海流的记录长度平均地转估计为4.7Sverdraps(Sv；1Sv=106m~3/S)，日时间标准差为7.5Sv。安的列斯海流输送的变化超过了整个盆地经向翻转环流的变化，说明了这种异常海流的影响。季节变率表现出8-9月的最大北上输送；然而，变率的季节分量很弱，即使有10.5年的资料，高频的混叠仍然是一个问题。频谱变化的主要时间尺度是70天和180天，有迹象表明罗斯比波状特征以9厘米/S的速度向西传播到该地区。安的列斯海流输送变化与27°N的佛罗里达海流输送变化之间没有显著的相关性，同步或延迟/超前长达5年，可能反映了信息从盆地内部通过巴哈马群岛传递的海岸波/墙急流的不同时间尺度。
Observations from five different systems provide a robust picture of the structure and variability of the Antilles Current, an important contributor to the oceanic flux budget, at 26.5°N during 2005–2015. The analysis includes three direct measurement technologies (current meters, shipboard acoustic Doppler current profilers, and lowered acoustic Doppler current profilers) and two geostrophy‐based measurement technologies (conductivity‐temperature‐depth profilers and pressure‐equipped inverted echo sounders). The direct systems are shown to produce weaker, and less variable, Antilles Current transport estimates than the geostrophy‐based systems. The record‐length‐mean geostrophic estimate for the Antilles Current is 4.7 Sverdrups (Sv; 1 Sv = 106m3/s), and the daily temporal standard deviation is 7.5 Sv. The variations of the Antilles Current transport exceed those of the entire basin‐wide meridional overturning circulation, illustrating the impact of this unusual current. Seasonal variability shows a maximum northward transport in August–September; however, the seasonal component of the variability is weak, and aliasing of higher frequencies is still a problem even with 10.5 years of data. The dominant time scales of variability in the spectra are at 70 and 180 days, and there is indication of westward propagation of Rossby Wave‐like features into the region at a speed of 9 cm/s. There is no significant correlation between the Antilles Current transport variations and those of the Florida Current at 27°N, in phase or at lags/leads of up to 5 years, likely reflecting the varying coastal wave/wall jet time scales for information to pass from the basin interior through the Bahamas Islands.