赤道不稳定波能量收支的数值模拟分析
-
摘要: 最新海表温度卫星观测资料分析表明在赤道东太平洋和大西洋附近存在赤道不稳定波(tropical instability waves)。赤道不稳定波通常于每年春末夏初出现,以约0.6 m/s速度向西传播,周期为20~40天左右,波长约为1 000~2 000 km,可改变赤道附近海洋的热量平衡,并引发强烈的局地海气作用。利用CCSR/NIES/FRCGC AOGCM MIROC 100年的模式输出结果,计算了赤道不稳定波的爆发时间、波长、传播速度、周期,并与观测资料作对比分析,以考察模式对赤道不稳定波的模拟能力。结果表明,模式较好地再现了热带太平洋的海洋内部中尺度动力-热力作用过程,成功模拟了赤道不稳定波的基本特征,发现赤道不稳定波主要存在赤道南北不超过6个纬度的浅层海洋中,除赤道表层外4~6 ?N海洋温跃层中也有赤道不稳定波。对赤道不稳定波的能量进行诊断分析表明其能量主要来自赤道附近洋流经向切变产生的正压不稳定,赤道以北海洋温跃层中赤道不稳定波能量主要来自由浮力作用产生的斜压不稳定,两者的共同作用形成了赤道不稳定波的赤道不对称结构。
-
[1] DUEING W, HISARD P, KATZ E, et al. Meanders and long waves in the equatorial Atlantic[J]. Nature, 1975, 257(5524): 280-284.[2] LEGECKIS R. Long waves in the eastern equatorial Pacific Ocean: A view from a geostationary satellite[J]. Science, 1977, 197(4309): 1 179-1 181.[3] 陈鲜艳,胡博,木本昌秀, 等. 赤道不稳定波对海气相互作用影响的数值模拟分析[J]. 大气科学,2009,33(1):145-154.[4] SWENSON M S, HANSEN D V. Tropical Pacific Ocean mixed layer heat budget: The Pacific cold tongue[J]. J Phys Oceanogr, 1999, 29(1): 69-81.[5] WEISBERG R H, WEINGARTNER T J. Instability waves in the equatorial Atlantic Ocean[J]. J Phys Oceanogr, 1988, 18(11): 1 641-1 657.[6] PHILANDER S G H. Instabilities of zonal currents, 1[J]. J Geophys Res, 1976, 81(21): 3 725-3 735.[7] PHILANDER S G H. Instabilities of zonal currents, 2[J]. J Geophys Res, 1978, 83(C7): 3 679-3 682.[8] COX M. Generation and propagation of 30-day waves in a numerical model of the Pacific[J]. J Phys Oceanogr, 1980, 10(8): 1 168-1 186.[9] SEMTNER A J, HOLLAND W R. Numerical simulation of equatorial ocean circulation, 1: A basic case in turbulent equilibrium[J]. J Phys Oceanogr, 1980, 10(5): 667-693.[10] HANSEN D V, PAUL C A. Genesis and effects of long waves in the equatorial Pacific[J]. J Geophys Res, 1984, 89(6): 10 431-10 440.[11] LUTHER D S, JOHNSON E S. Eddy energetics in the upper equatorial Pacific during the Hawaii-to-Tahiti Shuttle Experiment[J]. J Phys Oceanogr, 1990, 20(7): 913-944.[12] MASINA S, PHILANDER S. An analysis of tropical instability waves in a numerical model of the Pacific Ocean, 1: Spatial variability of the waves[J]. J Geophys Res, 1999, 104(C12): 29 613-29 635.[13] MASINA S, PHILANDER S, BUSH A. An analysis of tropical instability waves in a numerical model of the Pacific Ocean, 2: Generation and energetics of the waves[J]. J Geophys Res, 1999, 104(C12): 29 637-29 661.[14] HASUMI H, EMORI S K-1. Coupled model(MIROC) description[R]. Cent For Clim Syst Res, Univ of Tokyo, Kashiwa. 2004, 1: 34.[15] HASUMI H. CCSR ocean component model(COCO) version 2.1[R]. Cent For Clim Syst Res, Univ of Tokyo, Kashiwa, CCSR report, 2000,13: 68.[16] CHEN X, KIMOTO M, TAKAHASHI M. Changes in ENSO in response to greenhouse warming as simulated by the CCSR/NIES/FRCGC coupled GCM[J]. SOLA, 2005, 1(1): 149-152.[17] KIMOTO M. Simulated change of the east Asian circulation under global warming scenario[J]. Geophys Res Lett, 2005, 32: L16701.[18] 胡博, 李维京, 陈鲜艳, 等. 全球增暖对ENSO影响的数值模拟研究[J]. 大气科学,2007,31(2):214-221.[19] ACHUTARAO K, SPERBER K R. Simulation of the El Ni?o Southern Oscillation: results from the coupled model intercomparision project[J]. Clim Dyn, 2002, 19(34): 191-209.[20] CHELTON D B, ESBENSEN S K, SCHLAX M G, et al. Observations of coupling between surface wind stress and sea surface temperature in the eastern tropical Pacific[J]. J Climate, 2001, 14(7): 1 479-1 498.[21] 张韧, 何金海, 董兆俊, 等. 南亚夏季风影响西太平洋副高南北进退活动的小波包能量诊断[J]. 热带气象学报,2004, 20(2): 113-121.[22] 何金海, 董敏, 蒋国荣, 等. 有关全球变暖对热带大气季节内振荡特征的影响及其数值模拟的研究[J]. 气象与减灾研究,2006, 29(1): 17-21.[23] FLAMENT P, KENNAN S, KNOX R, et al. The three-dimensional structure of an upper ocean vortex in the tropical Pacific[J]. Nature, 1996, 383(6601): 610-613.[24] QIAO L, WEISBERG R H. Tropical instability wave energetics: Observations from the tropical instability wave experiment[J]. J Phys Oceanogr, 1998, 28(2): 345-360.
点击查看大图
计量
- 文章访问数: 2115
- HTML全文浏览量: 0
- PDF下载量: 1521
- 被引次数: 0