摘要
对大气环流模式PIAP3进行了30 a季节运行,对其物理过程的温度调整倾向进行了系统分析,研究发现:大气总辐射效应以冷却为主,长波辐射温度倾向与温度本身具有负反馈关系,与云量有正反馈关系。太阳短波辐射加热倾向直接反映了太阳直射点冬夏的季节转换;深厚对流和大尺度降水,作为大气的重要加热机制,是辐射冷却的重要平衡因子,两者地域互补,前者加热热带深厚大气,后者主要加热中高纬对流层中低层大气。干、湿对流是低层大气热力混合的有效机制,分别完成北半球中高纬和热带地区的低层热力混合,两者共同作用消除不稳定。垂直涡旋扩散与浅积云对流对低层大气形成热量传输的互补匹配,两者分别实现陆面和海面低层大气热量的有效传输混合,并共同构成下垫面边界层和自由大气间的有效垂直传输机制。浅对流活跃区处于强盛深厚对流区的下游方向,大尺度层结降水有利于浅积云的发展。物理过程净温度调整是各过程调整平衡的结果,除赤道南北两侧的热带地区存在两个深厚的温度调整柱外,边界层以上的整个对流层主体均以降温为主,而边界层以下则以加热为主。
30-year seasonal running was performed on AGCM PIAP3 and the temperature tendencies of its physical parameterizations were also systematically analyzed. Results showed that the net radiative effect was mainly cooling the air,and the temperature tendency of long wave radiation followed negative feedback relation with the temperature itself but positive one with cloudiness. The heating tendency of short wave radiation directly reflected the seasonal transition of the subsolar point. As the important heating mechnism of the atmosphere,both the deep convection and large scale precipitation were the main balance factors in counteracting the radiative cooling. The occurring regions of deep convection and large scale precipitation were separable,the former primarily heated the tropical deep air,and the later mainly heated the lower troposphere in mid-high latitude. The dry and moist adiabatic convections were the effective mechanisms in the thermal exchanging of lower air,both of which eliminated the instabilities in lower mid-high latitude in north hemisphere and in lower tropical air,respectively. Both vertical eddydiffusion and shallow convection were combined together to carry out the complementary thermal transmission for lower air and to realize the thermal blending of lower air over land surface and ocean surface,so that an effective vertical transmission mechanism between surface and free air was built. Shallow convection was generally located at the lee of deep convection and was reinforced by large scale precipitation.The net temperature tendency in physical parameterizations was achieved by the counteracting of each tendency,which cooled down the upper air above the boundary layer and made the air in the boundary layer warmer. Additionally,two deep temperature adjusting-columns appeared in both sides of equator.
出处
《气象科学》
北大核心
2015年第3期279-288,共10页
Journal of the Meteorological Sciences
基金
国家重点基础研究发展计划(973计划)项目(2013CB956203)
国家自然科学基金资助项目(41475071)
关键词
温度
大气环流模式(PIAP3)
物理过程
Temperature
Atmospheric general circulation model（PIAP3）
Physical parameterizations
