南极地区冰雪消失对全球大气环流和气候影响的数值模拟

NUMERICAL SIMULATION OF INFLUENCE OF ANTARCTIC LAND ICE-SNOW COVER DISAPPEARANCE ON ATMOSPHERIC GENERAL CIRCULATION AND CLIMATE

本文利用全球大气环流模式通过数值模拟研究了北半球夏季南极地区冰雪覆盖的消失对大气环流和全球气候影响的过程。结果表明南极冰雪消失不仅影响南半球大气环流异常,而且通过引起热带环流异常如增强东亚季风环流和减弱Walker环流等引起北半球大气环流和我国夏季气候的异常。南极冰雪覆盖的消失将给全球气候带来严重后果。文中也对南极冰雪气候效应的动力学机制进行了讨论。

By using a perpetual July, nine-level general circulation spectral model with rhomboidal truncation at wavenumber 15, incorporated with a comprehensive set of physical processes, two numerical experiments,i, e. one with normal Antarctic land ice-snow cover and the other without Antarctic land ice-snow cover,were conducted to study the influence of the removal of Antarctic land ice-snow cover on general circulation of atmosphere and global climate. The results exhibit that the removal of Antarctic land ice-snow cover may induce global atmospheric anomalies, which is characterized by 1)The increase of air temperature with a maximum abnormal center exceeding 6. 0 degree in the Antarctic land areas and the weakening of Antarctic polar vortex and westerlies at the high latitudes of Southern Hemisphere,2)The anomalies of ultra-long waves especially those at wavenumber 3 in the Southern Hemisphere, 3) The intensification of summer monsoon circulation of east Asia and the weakening of equatorial Walker circulation, 4) The increase of precipitation over east Asia and the coast areas and the decrease of that over equatorial western Pacific,5)The exciting of the two leading wavetrains of the east Asian and the Eurasian patterns in the Northern Hemisphere,6)Climatic anomalies in China with decrease of air temperature in northeastern China and with increase of precipitation in southern China. Therefore, the Antarctic land ice-snow cover plays an important role in the formation of general circulation and climate. The removal of it may lead a serious consequence for global climate. The dynamical mechanism of climatic effect of Antarctic land ice-snow cover is also discussed in this paper.