太阳活动11年周期与南极海冰的可能联系  

POSSIBLE LINKAGES BETWEEN THE 11-YEAR SOLAR CYCLE AND ANTARCTIC SEA ICE VARIABILITY

作　　者：周群[1] 陈文[2] Zhou Qun;Chen Wen(National Marine Environmental Forecasting Center,Ministry of Natural Resources,Beijing 100081,China;Center for Monsoon System Research,Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]自然资源部国家海洋环境预报中心,北京100081 [2]中国科学院大气物理研究所季风系统研究中心,北京100190

出　　处：《极地研究》2020年第3期290-300,共11页Chinese Journal of Polar Research

基　　金：国家自然科学基金(41505050)资助。

摘　　要：本文利用1979—2018年NCEP-DOE再分析资料、Hadley中心提供的全球海冰密集度格点资料以及反映太阳活动11年周期变化的太阳黑子数资料,研究了太阳活动与南极海冰变化的可能联系和其中涉及的物理过程。结果表明,太阳活动偏强年,南极半岛-威德尔海海冰密集度增加,罗斯海外围海冰密集度减少,反之亦然。通过定义一个反映上述变化的南极海冰偶极子指数,我们发现其与南极涛动(Antarctic Oscillation,AAO)的变化具有显著的负相关关系,与AAO密切相联系的绕极急流的非对称性结构在这一过程中起到了关键作用。当AAO强度较强时,西风急流在南极半岛-威德尔海一带向南偏转,在罗斯海附近向北偏转,引起暖空气易于进入南极半岛-威德尔海,而更多的冷空气进入罗斯海外围,从而造成海冰分布的偶极子结构。而当AAO为负位相时,情况与上述相反。对流层AAO模态对太阳活动的响应,可能在太阳活动与南极海冰两者的联系中起到了桥梁作用。进一步的研究揭示出太阳活动影响AAO的信号很可能源于平流层温度的响应,再通过对流层的平均经圈环流的调整,大气质量得以重新分布,在太阳活动偏强年,对流层低层易于出现负的AAO型响应。Using NCEP-DOE reanalysis datasets,sea ice concentration data from the Hadley Center and sunspot number data,we investigated possible linkages between Antarctic sea ice and the 11-year solar cycle as well as related physical processes.In years with high solar activity,sea ice concentration is low in the vicinity of the Ross Sea and high in the Weddell Sea near the Antarctic Peninsula.We introduced a sea ice dipole(SID)index,and found that Antarctic SID is significantly negatively correlated with the Antarctic Oscillation(AAO),possibly through the mediation of the westerly jet.When the AAO is strong,the westerly stream turns southward around the Antarctic Peninsula–Weddell Sea,and northward near the Ross Sea,resulting in negative SID anomalies as warm air enters the Antarctic Peninsula–Weddell Sea region and cold air intrudes over the Ross Sea.Sea ice and circulation anomalies are reversed when the AAO is weak.This indicates that solar activity and Antarctic sea ice variability may be linked through the effects of solar activity on AAO,which may originate from temperature responses in the stratosphere.As a result of changes in meridional circulation,redistribution of air masses in the atmosphere tends to induce negative AAO in the lower troposphere during years with high solar activity.

关 键 词：太阳活动 南极海冰 南极涛动 

分 类 号：P182[天文地球—天文学] P731.15