摘要
利用1950—2020年冬季HadISST逐月海面温度(sea surface temperature, SST)资料、SODAv2.2.4逐月SST和三维海洋流速同化资料以及NCEP/NCAR 2 m高度上的逐月气温(surface air temperature, SAT)资料,使用非对称合成差分析方法、海洋混合层热量收支诊断方法等,探究El Ni1o事件和La Ni1a事件下造成赤道东太平洋(E区:110°W~80°W,10°S~10°N)、赤道中太平洋(C区:160°E~170°W,10°S~10°N)SST异常场显著不同非对称性特征的可能海洋动力过程,分析ENSO事件非对称强迫下2 m高度上SAT异常场的非对称空间响应。结果表明:E区El Ni1o事件的强度显著强于La Ni1a事件,C区则相反。非线性动力学加热作用对E区和C区El Ni1o年和La Ni1a年SST异常场的非对称分量都起到了正反馈作用,是造成这两个区域SST异常场产生正、负非对称分量的主导动力因子。埃克曼输送作用不利于E区SST异常场正非对称分量的形成,但有利于C区SST异常场负非对称分量的形成。平均流、纬向平流和温跃层的非对称正反馈作用阻碍了C区SST异常场负非对称分量的形成。2 m高度上SAT异常场的非对称分布与SST异常场的非对称分布较为一致,但SAT异常场正、负非对称分量的显著范围明显减小,部分区域的非对称结果不显著。
The study uses monthly sea surface temperature(SST)data from HadISST,monthly SST and three-dimensional ocean current velocity assimilation data from SODAv2.2.4,and monthly surface air temperature(SAT)at 2 m from NCEP/NCAR during 1950-2020 in winter.Combined with the asymmetric composite difference analysis method and mixed layer heat budget analysis method,the possible ocean dynamic processes of significantly asymmetric SST anomaly over the eastern(E region:110°W-80°W,10°S-10°N)and central(C region:160°E-170°W,10°S-10°N)equatorial Pacific under El Ni o and La Ni a events are explored.The asymmetric spatial responses of SAT anomaly at 2 m under asymmetric forcing of ENSO events are also analyzed.The results show that El Ni o events are significantly stronger than La Ni a events in the E region,while the C region is the opposite.The contribution of nonlinear dynamic heating to the asymmetric components of SST anomaly in El Ni o and La Ni a years over the E and C regions is positive feedback,and it is the dominant dynamic factor that causes the positive and negative asymmetric components of SST anomaly in these two regions.Ekman pumping is unfavorable for the formation of the positive asymmetric component of the SST anomaly in the E region,but favorable for the formation of the negative asymmetric component of the SST anomaly in the C region.The formation of the negative asymmetric component of SST anomaly in the C region is damped by the positive feedback of mean circulation,zonal advection,and thermocline feedback.The asymmetric distribution of SAT anomaly at 2 m is consistent with the asymmetric spatial distribution of SST anomaly.However,the significant range of positive and negative asymmetric components of SAT anomaly is evidently reduced,and the asymmetric results in some areas are not significant.
作者
张文珺
李建平
ZHANG Wenjun;LI Jianping(Frontiers Science Center for Deep Ocean Multispheres and Earth System,Ocean University of China,Qingdao 266100,China;Key Laboratory of Physical Oceanography of Ministry of Education,Ocean University of China,Qingdao 266100,China;College of Oceanic and Atmospheric Sciences,Ocean University of China,Qingdao 266100,China;Academy of the Future Ocean,Ocean University of China,Qingdao 266100,China;Laboratory for Ocean Dynamics and Climate,Pilot National Laboratory for Marine Science and Technology(Qingdao),Qingdao 266237,China)
出处
《海洋气象学报》
2024年第1期1-13,共13页
Journal of Marine Meteorology
基金
国家自然科学基金重大项目(41790474)
山东省自然科学基金重大基础研究项目(ZR2019ZD12)。
关键词
ENSO
非对称性
热收支分析
El Ni o-Southern Oscillation(ENSO)
asymmetry
heat budget analysis
