| 卑尔根气候模式中大西洋热盐环流年代际与年际变率的气候影响 |
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| 引用本文： | 周天军,Helge DRANGE.卑尔根气候模式中大西洋热盐环流年代际与年际变率的气候影响[J].大气科学,2005,29(2):167-177. |
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| 作者姓名： | 周天军 Helge DRANGE |
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| 作者单位： | 中国科学院大气物理研究所大气科学与地球流体力学数值模拟国家重点实验室,北京,100029;Nansen Environmental and Remote Sensing Center,Bergen,Norway |
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| 基金项目： | 国家自然科学基金;中国科学院知识创新工程项目;国家重点基础研究发展计划(973计划) |
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| 摘 要： | 利用一个全球海气耦合模式--卑尔根气候模式的积分结果,揭示了与大西洋热盐环流(THC)年代际和年际振荡相对应的气候异常型.年代际振荡发生在全海盆尺度,伴有亚速尔高压的增强、冰岛低压的加深;年际振荡发生在局地尺度,伴有亚速尔高压的减弱.这两种海平面气压异常型都反映了北大西洋涛动(NAO)活动中心的强度变化,两种变率型对应的拉布拉多海对流活动都加剧.但伴随局地尺度的THC调整,伊尔明格海的对流活动减弱.蒸发异常对拉布拉多海表层盐度异常的影响较为显著.分析表明,局地尺度的THC振荡主要是对大气强迫的被动响应,而海盆尺度THC振荡的实质是反映整个输送带的强度变化,其气候意义要大于THC的局地振荡.
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| 关 键 词： | 热盐环流 北大西洋涛动 年代际变率 年际变率 |
| 文章编号： | 1006-9895(2005)02-0167-11 |
Climate Impacts of the Decadal and Interannual Variability of the Atlantic Thermohaline Circulation in Bergen Climate Model |
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| ZHOU Tian-Jun and Helge DRANGE.Climate Impacts of the Decadal and Interannual Variability of the Atlantic Thermohaline Circulation in Bergen Climate Model[J].Chinese Journal of Atmospheric Sciences,2005,29(2):167-177. |
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| Authors: | ZHOU Tian-Jun and Helge DRANGE |
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| Abstract: | Climate impacts of the basin-scale and local-scale oscillations of the Atlantic thermohaline circulation (THC) are identified by using Bergen Climate Model (BCM). The basin-wide oscillation occurs at decadal scales with strong cross-equatorial flow, the more localized fluctuation of the THC occurs mainly at interannual scales with weaker cross-equatorial flow. The basin-wide THC oscillation is associated with an intensified Azores high and Icelandic low,the local-scale THC adjustment is accompanied with a negative phase-like North Atlantic Oscillation (NAO). The atmospheric circulation change results in an intensified deep convection in the Labrador Sea in both cases. For the local-scale THC adjustment, the Irminger Sea is dominated by a weakened convection. Surface salinity anomalies in the Labrador Sea are created locally by evaporation anomalies at the sinking regions. Further analyses support that the local-scale THC oscillation is caused passively by the atmosphere forcing. There are evidences indicating that the whole THC conveyor accelerating generates the warmer sub-polar SST, which warms the air and enhances the surface evaporation. |
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| Keywords: | thermohaline circulation North Atlantic oscillation decadal and interannual variability modes |
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