Decadal variability in the oxygen inventory of North Atlantic subtropical underwater captured by sustained, long‐term oceanographic time series observations
Decadal variability in the oxygen inventory of North Atlantic subtropical underwater captured by sustained, long‐term oceanographic time series observations
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通过持续的长期海洋学时间序列观测捕获北大西洋副热带水下氧气库存的年代际变化
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
S. Habtes
中科院分区：
文献类型：
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作者：
E. Montes;F. Muller‐Karger;A. Cianca;M. Lomas;L. Lorenzoni;S. Habtes
为了了解热带和副热带北大西洋(0-40°N，10-90°W)潜温(θ)、盐度(S)和溶解氧浓度(O2)的年代际变化，对热带和副热带北大西洋(0-500STUW；0-40°N，10-90°W)进行了历史观测。在持续时间最长、持续时间最长的四个海洋生物地球化学和生态时间序列站点上观测到了STUW，这些站点是彩色海洋碳保持量海洋时间序列方案(10.5°N，64.7°W)、百慕大大西洋时间序列研究(BATS；31.7°N，64.2°W)、“S”水电站(32.1°N，64.4°W)和加那利群岛海洋时间序列欧洲站(ESTOC；29.2°N，15.5°W)。在加勒比(1996年至2013年)、巴特斯(1988年至2011年)和S水电站(1980年至2013年)类似时间段的观测显示，STUW O2分别下降了约0.71、0.28和0.37 微摩尔 kg−1 yr−1。在时间序列(1994-2013年)期间，ESTOC没有观察到STUW O2的明显变化。美国国家海洋与大气局国家海洋数据中心存档的热带和亚热带北大西洋船舶观测数据显示，1980年至2013年期间，加勒比海东南部(10-15°N，60-70°W)热带和亚热带北大西洋(30-35°N，60-65°W)的STUW O2(上层~300 m)下降了0.58 / kg−1 yr−1和0.68 / kg−1 yr−1。同期在副热带北大西洋东部(25-30°N，15-20°W)没有观测到O2的下降趋势。观测到的大部分氧气损失似乎是由于与风力驱动混合减少和STUW形成速度减慢相关的通风变化造成的，而不是大气-海洋氧气扩散交换的变化或北大西洋生物海洋学的变化。STUWO2变率与冬季(1~3月)大西洋年代际涛动指数(AMO，R2 = 0.32)呈显著正相关。在负冬季AMO年，10°N到30°N之间的信风通常较强，这些条件促进了STUW的形成和通风。从1980年到2013年的30年间，STUW O2的下降趋势反映了从20世纪80年代中期到90年代中期的冬季AMO强烈负的转变，到90年代中期到2013年观察到的冬季AMO的正变化。CARIACO、BATS和S水文站记录了STUWO2的这些变化。持续的正AMO条件可能导致热带和亚热带北大西洋上层水域进一步脱氧。
Historical observations of potential temperature (θ), salinity (S), and dissolved oxygen concentrations (O2) in the tropical and subtropical North Atlantic (0–500 m; 0–40°N, 10–90°W) were examined to understand decadal‐scale changes in O2 in subtropical underwater (STUW). STUW is observed at four of the longest, sustained ocean biogeochemical and ecological time series stations, namely, the CArbon Retention In A Colored Ocean (CARIACO) Ocean Time Series Program (10.5°N, 64.7°W), the Bermuda Atlantic Time‐series Study (BATS; 31.7°N, 64.2°W), Hydrostation “S” (32.1°N, 64.4°W), and the European Station for Time‐series in the Ocean, Canary Islands (ESTOC; 29.2°N, 15.5°W). Observations over similar time periods at CARIACO (1996–2013), BATS (1988–2011), and Hydrostation S (1980–2013) show that STUW O2 has decreased approximately 0.71, 0.28, and 0.37 µmol kg−1 yr−1, respectively. No apparent change in STUW O2 was observed at ESTOC over the course of the time series (1994–2013). Ship observation data for the tropical and subtropical North Atlantic archived at NOAA National Oceanographic Data Center show that between 1980 and 2013, STUW O2 (upper ~300 m) declined 0.58 µmol kg−1 yr−1 in the southeastern Caribbean Sea (10–15°N, 60–70°W) and 0.68 µmol kg−1 yr−1 in the western subtropical North Atlantic (30–35°N, 60–65°W). A declining O2 trend was not observed in the eastern subtropical North Atlantic (25–30°N, 15–20°W) over the same period. Most of the observed O2 loss seems to result from shifts in ventilation associated with decreased wind‐driven mixing and a slowing down of STUW formation rates, rather than changes in diffusive air‐sea O2 gas exchange or changes in the biological oceanography of the North Atlantic. Variability of STUW O2 showed a significant relationship with the wintertime (January–March) Atlantic Multidecadal Oscillation index (AMO, R2 = 0.32). During negative wintertime AMO years trade winds are typically stronger between 10°N and 30°N. These conditions stimulate the formation and ventilation of STUW. The decreasing trend in STUW O2 in the three decades spanning 1980 through 2013 reflects the shift from a strongly negative wintertime AMO between the mid‐1980s and mid‐1990s to a positive wintertime AMO observed between the mid‐1990s and 2013. These changes in STUW O2 were captured by the CARIACO, BATS, and Hydrostation S time series stations. Sustained positive AMO conditions could lead to further deoxygenation in tropical and subtropical North Atlantic upper waters.
影响因子：
5.8
作者：
Chollett, Iliana;Mueller-Karger, Frank E.;Mumby, Peter J.
通讯作者：
Mumby, Peter J.
影响因子：
56.9
作者：
Stramma, Lothar;Johnson, Gregory C.;Mohrholz, Volker
通讯作者：
Mohrholz, Volker