冷暖事件对大气能量循环和纬向平均环流影响的模拟研究

利用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新发展的GOALS 5全球海 陆 气耦合模式研究了暖事件 (ElNi no)和冷事件 (LaNina)对大气能量循环和纬向平均环流的影响 ,并用观测资料进行了对比分析。结果表明 :对于纬向平均资料来说 ,冷、暖事件在热带和副热带地区的大气环流相关量的反相变化特征非常清晰 ,中高纬度地区并不明显。此外 ,还发现 ,暖事件时定常涡动的经向热通量的变化是北半球对流层热带外地区温度异常的主要原因 ,而瞬变波的影响则起抵消作用。冷事件时定常波和瞬变波相互抵消的局地特征也依然存在 ,但瞬变波的影响有所增强。

SIMULATION OF THE IMPACT OF WARM AND COLD EVENTS ON ATMOSPHERIC ENERGY CYCLE AND ZONAL MEAN ATMOSPHERIC CIRCULATION

The newly developed Global Ocean-Atmosphere-Land System model(GOALS-5) is employed to investigate the impact of warm(El Nio)and cold(La Nina)events on the atmospheric energy cycle and zonal mean atmospheric circulation, compared to the results of real climate. The analyses show that for the zonally averaged data, most of zonal anomalies of basic atmospheric fields and quantities related to the energy cycle take on obviously opposite changes in the tropics and subtropics between warm and cold events, which does not happen in the mid-latitudes and high-latitudes regions. According to our investigation, during warm episode the change in meridional heat fluxes by the stationary eddies is identified to be the cause for the temperature anomalies in the extratropical Northern Hemisphere troposphere, while the transient eddies give an opposing contribution. During cold episode there is still some compensation of the stationary eddy heat transports by the transient eddy, while impacts of the transient eddy are somewhat enhanced.