基于WOA18(World Ocean Atlas)温盐数据集,分析印度洋等密度面的气候态分布,而后选取1985—1994年、1995—2004年和2005—2017年3个时段,分析等密度面的年代际变化。研究给出了11个等密度面深度的气候态分布,其中σ0=26.00 kg/m3的等密度面(参考压强为0 dbar)在 40°S附近露头,随着位势密度的增大,等密度面露头区逐渐南移直至消失;位势密度大于σ0=26.95kg/m3且小于等于σ2=37.00kg/m3的等密度面最深处均位于马达加斯加南侧,在北印度洋的深度变化不大。重点分析了σ0=26.00 kg/m3,σ1=31.87 kg/m3(参考压强为1 000 dbar),σ2=36.805 kg/m3(参考压强为2 000 dbar)3个等密度面深度和盐度的年代际变化,研究表明两者均存在显著的年代际变化。对于σ0=26.00kg/m3等密度面,深度先变浅后加深,年代际变化主要位于30°S—40°S(等密度面深度快速变化区);等密度面盐度在1995—2004年和1985—1994年的差异与2005—2017年和1995—2004年的差异中基本呈现相反的变化。 σ1=31.87kg/m3和σ2=36.805kg/m3的等密度面深度年代际变化都集中于40°S—50°S海域;总体上盐度的年代际变化前者表现为减小,后者表现为增加。
Abstract
The climatology distribution of isopycnal layer in the Indian Ocean were analyzed based on the WOA18 (World Ocean Atlas 2018) dataset firstly. And then three time periods were defined as 1985-1994, 1995-2004 and 2005-2017 to research the decadal variation. The results show the climatology distributions of 11 isopycnal layers. As far as σ0=26.00kg/m3 (reference pressure as 0 dbar) isopycnal layer was concerned, the layer was outcropping at roughly 40°S. As the potential density increased, the outcrop area of the isopycnal layer gradually moved southward until it disappeared. When the potential density was greater than σ0=26.95 kg/m3 and less than or equal to σ2=37.00kg/m3, the deepest part of the isopycnal layers were located in southern Madagascar, and the depth of the North Indian Ocean was almost the same. Furthermore, present study investigates the decadal variances of depth and salinity of isopycnal layers, where the three layers include σ0=26.00 kg/m3, σ1=31.87 kg/m3 (reference pressure as 1 000 dbar) and σ2=36.805kg/m3 (reference pressure as 2 000 dbar). Studies show that the depth and salinity of the isopycnal layer had significant decadal changes in the three periods from 1985 to 2017. For the isopycnal layer of σ0=26.00kg/m3, the depth decreased first and then increased during the three periods. And the decadal variation of the isopycnal depth was mainly located in 30°S-40°S(the rapid change area of the isopycnal depth). The difference of salinity between 1995-2004 and 1985-1994 was basically opposite to the difference between 2005-2017 and 1995-2004 when the isopycnal layer was σ0=26.00kg/m3. For the isopycnal layer of σ1=31.87kg/m3 and σ2=36.805kg/m3, the decadal variations of the depth were concentrated on 40°S-50°S. Overall, the salinity of σ1=31.87kg/m3 show a decreasing trend but σ2=36.805kg/m3 show an increase trend.
关键词
印度洋 /
等密度面 /
年代际变化
Key words
the Indian Ocean /
isopycnal layer /
decadal variance
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] CESSI P. The global overturning circulation[J]. Annual Review of Marine Science, 2019, 11(1): 249-270.
[2] SCHOTT F A, XIE Shangping, MCCREARY JR J P. Indian Ocean circulation and climate variability[J]. Reviews of Geophysics, 2009, 47(1): RG1002.
[3] ZIKA J D, ENGLAND M H, SIJP W P. The ocean circulation in thermohaline coordinates[J]. Journal of Physical Oceanography, 2012, 42(5): 708-724.
[4] SCHOTT F A, MCCREARY JR J P. The monsoon circulation of the Indian Ocean[J]. Progress in Oceanography, 2001, 51(1): 1-123.
[5] WANG Weiqiang, KÖHL A, STAMMER D. The deep meridional overturning circulation in the Indian Ocean inferred from the GECCO synthesis[J]. Dynamics of Atmospheres and Oceans, 2012, 58(11): 44-61.
[6] WANG Weiqiang, ZHU Xiuhua, WANG Chunzai, et al. Deep meridional overturning circulation in the Indian Ocean and its relation to Indian Ocean Dipole[J]. Journal of Climate, 2014, 27(12): 4508-4520.
[7] LUYTEN J R, PEDLOSKY J, STOMMEL H. The ventilated thermocline[J]. Journal of Physical Oceanography, 1983, 13(2): 292-309.
[8] BEAL L M, FFIELD A, GORDON A L. Spreading of Red Sea overflow waters in the Indian Ocean[J]. Journal of Geophysical Research: Oceans, 2000, 105(C4): 8549-8564.
[9] REID J L. On the total geostrophic circulation of the Indian Ocean: Flow patterns, tracers, and transports[J]. Progress in Oceanography, 2003, 56(1): 137-186.
[10] MCCREARY JR J P, LU Peng. Interaction between the subtropical and equatorial ocean circulations: The subtropical cell[J]. Journal of Physical Oceanography, 1994, 24(2): 466-497.
[11] NAGURA M, MCPHADEN M J. The shallow overturning circulation in the Indian Ocean[J]. Journal of Physical Oceanography, 2018, 48(2): 413-434.
[12] DURACK P J, WIJFFELS S E. Fifty-year trends in global ocean salinities and their relationship to broad-scale warming[J]. Journal of Climate, 2010, 23(16): 4342-4362.
[13] SOLOMON S, MANNING M, MARQUIS M, et al. Climate change 2007: the physical science basis: Working group I contribution to the fourth assessment report of the IPCC[M]. Cambridge: Cambridge University Press, 2007: 23-30.
[14] GILLE S T. Warming of the Southern Ocean since the 1950s[J]. Science, 2002, 295(5558): 1275-1277.
[15] ALORY G, WIJFFELS S, MEYERS G. Observed temperature trends in the Indian Ocean over 1960-1999 and associated mechanisms[J]. Geophysical Research Letters, 2007, 34(2):L02606.
[16] HAN Weiqing, VIALARD J, MCPHADEN M J, et al. Indian Ocean decadal variability: A review[J]. Bulletin of the American Meteorological Society, 2014, 95(11): 1679-1703.
[17] ZWENG M M, REAGAN J R, SEIDOV D, et al. World ocean atlas 2018, volume 2: Salinity[Z]//MISHONOV A. NOAA Atlas NESDIS 82, 2019: 1-50.
[18] LOCARNINI R A, MISHONOV A V, BARANOVA O K, et al. World ocean atlas 2018, volume 1: Temperature[Z]//MISHONOV A. NOAA Atlas NESDIS 81, 2018.
[19] MCDOUGALL T J, BARKER P M. Getting started with TEOS-10 and the Gibbs Seawater (GSW) oceanographic toolbox[M]. SCOR/IAPSO WG, 2011: 1-28.
基金
中国科学院战略性先导科技专项(XDA20060501);中国大洋协会课题(DY135-E2-1-01,DY135-S2-1);南极重点海域对气候变化的响应与反馈(RFSOCC2020-2025);国家自然科学基金项目(41730535,41621064)
PDF(8935 KB)
