【作者】 闫巨盛； 王彰贵； 王盘兴； 李智峰；

【Author】 YAN Ju-sheng1,WANG Zhang-gui2,Wang pan-xing3 ,LI Zhi-feng4 (1.Hebei Province Meteorological Observatory,Shijiazhuang 050021,China;2.National Marine Environment Forecasting Center,Beijing 100081,China;3. Department Of Atmospheric Sciences,Nanjing University of Information Science and Technology, Nanjing 210044,China; Xingtai Meteorological Observatory,Xingtai 054000,Hebei Province,China)

【机构】 河北省气象台； 国家海洋环境预报中心； 南京信息工程大学大气科学系； 河北省邢台市气象局；

【摘要】 利用一个高分辨率的全球海洋环流模式MOM4,分别进行了赤道太平洋对大气热力强迫和风应力强迫的响应的数值试验,研究了赤道太平洋上层海温的年际变化特征及其和ENSO冷暖事件演变的关系。海洋表层的热力和风应力强迫场由取自NCEP/NCAR再分析资料1980-2000年的逐月平均值和德国OMIP数据集的气候值经模式计算而得。结果表明,在赤道太平洋表层,特别是在赤道东太平洋(5°S-5°N,160°W-80°W),热力作用对海表温度(SST)的影响不能忽视,热力强迫改进了单独风应力强迫对SST模拟的不足,使模拟与观测情况更加接近。结果还表明,模式基本能够模拟出这一时段ENSO循环中赤道太平洋次表层海温距平的整个演变过程,即次表层冷暖海水异常的堆积、沿次表层东传和抬升。在这一过程中,风应力强迫的作用是主导性的,而热力作用产生的影响较弱,是次要的。更多还原

【Abstract】 Numerical experiments are conducted by the use of a global tripolar grid ocean general circulation model derived from the Geophysical Fluid Dynamics Laboratory (GFDL) Modular Ocean Model (MOM4) with roughly "1-degree" resolution and 50 vertical levels to investigate the response of sea temperature interannual variations in the upper equatorial Pacific Ocean to wind stress forcing,thermal forcing and the two composite forcing,respectively ,and to simulate the evolution characteristics of the associated warm and cold events for the period 1980-2000.The model is forced by the sea surface thermal and wind stress forcing fields calculated in terms of the formulae within the model using the monthly mean atmospheric data such as 2-m air temperature,2-m specific humidity,sea lecel pressure,10-m wind speed, and the monthly mean surface flux data including clear sky downward longwave flux and net shortwave radiation taken from the NCEP/NCAR reanalysis. Other forcing data like precipitation are from the German OMIP-climatology.It is found that the model can reproduce the entire process of onset of El Ni?o/La Ni?a events whether wind stressal forcing or thermal forcing ,i.e. the buildup of sub-surface sea warm (cold) water anomalies in the equaorial western Pacific—propagating eastward and upward along the ocean climatic thermocline—occurrence of sea surface temperature (SST) anomalies in the equaorial eastern Pacific,whereas the composite focing is added to the model,the wind stress forcing has a dominant role and the thermal forcing takes second place in the process.The model results also suggest that the effect on SST of the thermal forcing can not be neglected in the equatorial Pacific,especially in the central and eastern Pacific,and the simulation is so well improved that it tends closely the observed values as result of the added thermal forcing.更多还原