南大西洋在地理上连接着北大西洋、南大洋和印度洋。通过环流输运或海表温度变化,该海域的上层海洋热含量(OHC)的变化可能对与之相连的各个洋盆间的再分布产生影响。本文基于1958—2015年的ORAS4全球海洋再分析数据和中国科学院大气物理研究所的格点海温数据集,利用经验正交函数(EOF)分析、相关分析等方法,分析了南大西洋上层海洋不同积分深度(0~100 m,0~300 m,0~500 m,0~700 m)OHC的时空变化特征。EOF第一模态显示,过去60 a来,南大西洋上层700 m存在一个洋盆尺度的变暖趋势,而且随着热含量积分深度的增加,第一模态所解释的方差占比也明显增加。OHC变化EOF第一模态与以年际变化为主的NAO和ENSO指数相关性很低,而与代表较长时间变率的AMO和PDO指数却有较好相关性,且与AMO的相关性随着积分深度的增加而提高。超前滞后相关分析显示AMO滞后南大西洋OHC变化9~12 a,显示南大西洋OHC变化对北大西洋气候变化的潜在影响。南大西洋OHC变化EOF第一模态与PDO之间相关性随着积分深度的增加而降低,显示PDO对OHC的影响主要在表层。另外发现整个洋盆的热含量变化与温跃层变化呈正相关,热含量的变化反映温跃层的动态波动。
Abstract
The South Atlantic Ocean (SAO) connects the North Atlantic, Indian and Southern Oceans. The variability of SAO Ocean Heat Content (OHC) would improve our understandings of the heat redistribution among global ocean basins in a warming climate. In is study, we analyze the spatial and temporal variability of the upper-layer OHC of SAO from European Centre for Medium-Range Weather Forecasts Ocean Reanalysis System 4 data sets and temperature data sets of Institute of Atmospheric Physics of the Chinese Academy of Sciences. Using empirical orthogonal function (EOF) analysis, the OHC of upper 700 m in the Southern Atlantic shows a basin wide warming during the past 60 years. This warming trend is even more apparent and have longer fluctuation cycle with a deeper integration depth for OHC. Correlation analysis shows that leading EOF mode of SAO OHC is dominated by decadal or longer time scale variabilities, with a 9-12 years leading of AMO, suggesting SAO OHC contribute to the North Atlantic climate variation. The SAO OHC-AMO correlation increases with the increased OHC integration depth while SAO OHC-PDO correlation decreases. Besides, it is found that variation of OHC in the whole basin is positively correlated with variation of thermocline depth, and the variation of OHC reflects the dynamical fluctuation in the thermocline.
关键词
南大西洋 /
海洋热含量 /
时空变化 /
AMO /
PDO
Key words
Southern Atlantic Ocean /
upper layer ocean heat content /
spatial and temporal variability /
AMO /
PDO
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参考文献
[1] FYFE J C. Making sense of the early-2000s warming slowdown[J]. Nat Climate Change,2016, 6(3): 224-228.
[2] YAN Xiao-hai,BOYER T, TRENBERTH K,et al.The global warming hiatus: Slowdown or redistribution[J]? Earth's Future,2016,4(11): 472-482.
[3] LEWANDOWSKY S,RISBEY J S,ORESKES N. The “pause” in global warming[J]. Bull Amer Meteor Soc, 2016, 97(5):723-733.
[4] MEEHL G A,ARBLASTER J M,FASULLO J,et al. Model-based evidence of deep-ocean heat uptake during surface-temperature hiatus periods[J].Nat Climate Change, 2011,1(7):360-364.
[5] MEEHL G A,ARBLASTER J M,FASULLO J,et al. Externally forced and internally generated decadalclimate variability associated with the interdecadal Pacific oscillation[J]. J Climate,2013,26(18): 7 298-7 310.
[6] ENGLAND M H,MCGREGOR S,SPENCE P,et al. Recent intensification of wind-driven circulation in the Pacific and the ongoing warm-ing hiatus[J]. Nat Climate Change, 2014,4(3): 222-227.
[7] DAI A,FYFE J C,XIE Shang-ping,et al. Decadal modulation of global surface temperature by internal climate variability[J].Nat Climate Change,2015,5(6): 555-559.
[8] MEEHL G A,SANTER B D,XIE S P. Contribution of the interdecadal Pacific oscillation to twentieth-century global surface temperature trends[J]. Nat Climate Change,2016, 6(11):1 005-1 008.
[9] KOSAKA Y,XIE Shang-ping. Recent global-warming hiatus tied to equatorial Pacific surface cooling[J]. Nature,2013,501(7 467): 403-407.
[10] KOSAKA Y,XIE Shang-ping. The tropical Pacific as a key pacemaker of the variable rates of global warming[J]. Nat Geosci,2016, 9(9): 669-673.
[11] MCGREGOR S,TIMERMANN A,STUECKER M F,et al. Recent Walker circulation strengthening and Pacific cooling amplified by Atlantic warming[J]. Nat Climate Change,2014,4(10): 888-892.
[12] LEE S K,PARK W,BARINGER M O,et al.Pacific origin of the abrupt increase in India Ocean heat content during the warming hiatus[J].Nat Geosci,2015,8(6): 445-449.
[13] NIEVES V,WILLS J K,PATZERT W C. Recent hiatus caused by decadal shift in Indo-Pacific heating[J]. Science, 2015,349(6 247):532-535.
[14] LIU Wei,XIE Shang-ping,LU Jian. Reply to: ‘Correspondence:Variations in ocean heat uptake during the surface warming hiatus’[J].Nat Commun,2016,7(48): 12 542.
[15] CHEN Xian-yao,TUNG K K.Varying planetary heat sink led to global-warming slowdown and acceleration[J]. Science,2014,345(6 199): 897-903.
[16] LEE S K,WONSUN P,ERIK V,et al. What caused the significant increase in Atlantic Ocean heat content since the mid-20th century[J]? Geophysical Research Letters, 2011, 38(17): L17607.
[17] CLEMENT A,BELLOMO K,MURPHY L N,et al.The Atlantic multidecadal oscillation without a role for ocean circulation[J]. Science, 2015,350(6 258): 320-324.
[18] MCCARTHY G D,HEIGH I D,CRIST J P,et al. Ocean impact on decadal Atlantic climate variability revealed by sea-level observations[J]. Nature,2015,521(7 553): 508-510.
[19] BALMASEDA M,MOGENSEN K,WEAVER A. Evaluation of the ECMWF ocean reanalysis system ORAS4[J]. Q J R Meteorol Soc,2013,139(674):1 132-1 161.
[20] CHENG Li-jing,TRENBERTH K E,PALMER M D,et al. Observed and simulated full-depth ocean heat content changes for 1970-2005[J].Ocean Science, 2016,12(4): 925-935.
[21] CHENG Li-jing,ZHU Jiang,ABRAHAM J. Global upper ocean heat content estimation: recent progress and the remaining challenges[J].Atmospheric and Oceanic Science Letters,2015(6):333-338.
[22] SPRINTALL J,TOMCZAK M. Evidence of the barrier layer in the surface layer of the tropics[J].Journal of Geophysical Research Atmospheres,1992, 97(C5):7 305-7 316.
[23] LIU Wei, XIE Shang-ping,LU Jian. Tracking ocean heat uptake during the surface warming hiatus[J].Nature Communications, 2016, 7(1): 10 926.
基金
中央高校基本科研业务费资助(2016B11614)
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