周天军,宇如聪,郜永祺,Helge Drange. 2006. 北大西洋年际变率的海气耦合模式模拟Ⅰ:局地海气相互作用[J]. 气象学报, 64(1):1-17, doi:10.11676/qxxb2006.001
北大西洋年际变率的海气耦合模式模拟Ⅰ:局地海气相互作用
IOCEAN-ATMOSPHERE COUPLED MODEL SIMULATION OF NORTH ATLANTICINTERANNUAL VARIABILITY I: LOCAL AIR-SEA INTERACTION
投稿时间:2005-07-18  修订日期:2005-10-08
DOI:10.11676/qxxb2006.001
中文关键词:  北大西洋涛动,年际气候变率,海气耦合模式,局地海气相互作用。
英文关键词:North Atlantic Oscillation,Interannual climate variability,Air-sea coupled model, Local air-sea interaction.
基金项目:国家重点基础研究专项经费资助的项目(2005CB321703)、中国科学院 创新团 队国际合作伙伴计划“气候系统模式研发及应用研究”和国家自然科学基金项目(4037502 9,40233031)。
作者单位
周天军 中国科学院大气物理研究所LASG北京 100029 
宇如聪 中国科学院大气物理研究所LASG北京 100029 
郜永祺 中国科学院大气物理研究所NZC北京100029
Nansen Environmental and Remote Sensing Center, Bergen, Norway 
Helge Drange Nansen Environmental and Remote Sensing Center, Bergen, Norway 
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中文摘要:
      检验了一个全球海气耦合模式对北大西洋年际气候变率的模拟,讨论了导致这种年际变率型的物理机制,并分析了其对年代际变率的可能影响。北大西洋冬季SST的主导变率模态,在经向上表现为三核型,自北而南出现“-+-”的带状距平型;最大距平中心位于副极地大洋、中纬度大洋的西部以及热带海域,耦合模式较为真实地再现了这一特征。与三核型SST异常相对应的大气环流型表现为北大西洋涛动,具有显著的正压结构。上述异常型主要发生在年际尺度,具有3—4年的谱峰;在次年代际尺度上,也存在谱峰。分析表明,模式中三核型SST异常的产生,主要来自大气的强迫,NAO增强,中纬度大洋上的西风减弱,海洋感热和潜热通量损失减少,中纬度大洋得到的净热通量增加,导致SST出现正距平;在包括Labrador 海在内的副极地大洋,NAO增强、冰岛低压加深,气旋性环流增强,来自高纬度的冷空气吹过洋面,海气温差加大,大洋的感热通量损失增加,SST降低。热带地区东风的增强,也是导致那里SST降低的重要机制。三核型SST异常对大气的反馈作用较弱,文中没有证据表明它能够影响到北大西洋地区的年代际气候变率。
英文摘要:
      The North Atlantic inter annual variability associated with the North Atlantic Oscillation (NAO) is examined in a 300 years integration of Bergen Clima te Model (BCM). The physical processes dominating the interannual scale tripolarpattern variability mode of the North Atlantic sea surface temperature (SST) are analyzed. Possible impacts of the tripolar SST anomalies on the decadal scale variability of the North Atlantic climate are also discussed. The dominant mod e of the North Atlantic wintertime SST variability exhibits a meridional tri-polar pattern, with a colder subpolar region, a warmer midlatitudes, and a colder region between the equator and 30°N. Validations on the model performance show that the BCM reproduces the observed NAO pattern and the tri-polar like SST vari ability mode successfully. The atmospheric circulation change associated with the tri-polar SST anomalies exhibits as NAO and has a barotropic structure. The power spectrum of the simulated NAO index is white and the interannual scale varia bility stands out, as the observational data reveals. The tripolar structure SST anomalies over the North Atlantic, which also appears at the interannual scale with a spectral peak at 3—4 years, are mainly resulted from the barotropic driving of the NAO like atmospheric forcing, and thermal process plays a dominantrole in this process. When the NAO is strong, the westerly weakens over the midlat itudes; both the sensible and the latent heat flux release from the ocean tend to decrease, which warms the ocean and leads to positive SST anomalies. Over the sub polar region including the Labrador Sea, a stronger NAO is associated with a deeper Icelandic Low; the high latitudes originated colder air then blows over the ocean surface, the air-sea temperature difference become larger, and the se n sible heat flux loss from the ocean increases, which subsequently leads to colder SST anomalies. The intensified easterly over the tropical area is also an impo rtant mechanism dominating the colder SST. The feedback of the tripolar SST anomalies on the atmosphere is weak. Further analysis reveals no evidence supportin g the possible feedback of the tripolar structure SSTA on the regional climate at multiannual and decadal scales.
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