摘要
两个因素将对21世纪平流层气候变化产生重要作用。一个是温室气体增加，另一个是平流层臭氧的可能恢复。温室气体增加的辐射效应一方面造成地面和对流层变暖，另一方面却导致平流层变冷，而臭氧层恢复的辐射效应则导致平流层变暖。在温室气体增加和臭氧恢复这两种相反因素作用下的平流层温度如何变化是所关心的主要问题。为了预估平流层温度在21世纪的变化，使用了辐射一对流模式进行了敏感性实验，另外，也对他人进行的化学一气候耦合模式（CCM）模拟结果进行了分析。这些模拟结果表明，在21世纪平流层中上层（60～1hPa）将变冷，而下层（150～60hPa）变暖。这说明在平流层中上层温室气体的冷却效应将起主导作用，而臭氧恢复的加热效应在平流层下层相对更为重要。CCM的模拟结果表明，臭氧恢复最显著的区域在平流层上层（3hPa附近），与最大降温区一致，说明温室气体增加将有利于平流层上层臭氧恢复。CCM的模拟结果还表明，平流层两极地区在冬半年存在变暖的现象。根据已有的研究结果，极区变暖与平流层行星波活动增强有关，动力、热力和化学之间的正反馈作用也有可能对极区变暖有重要的贡献。
There are two factors which will play the key roles in stratospheric climate changes in the 21st century. One is increasing greenhouse gases, and the other one is the likely recovery of stratospheric ozone. The radiative effect of increasing greenhouse gases causes warming on the surface and in the troposphere, but cooling in the stratosphere, whereas the recovery of the ozone layer will cause stratospheric warming. How stratospheric temperatures will be changed by the two opposite effects is the main interest in the present study. In order to explore changes in stratospheric temperatures, we carry out sensitivity simulations using a radiative-convective equilibrium mod- el, and we also analyze simulation results from coupled chemistry-climate models （CCM）. Our results show cooling trends in the middle and upper stratosphere （60 - 1 hPa） and warming in the lower layers （150 -60 hPa）. These suggest that the cooling effect of increasing greenhouse gases is more important in the middle and upper strato-sphere, while the warming effect of ozone recovery plays the major role in the lower stratosphere. CCM simulations show that the maximum ozone increase is in the upper stratosphere （ about 3 hPa） , which matches the layer of maximum cooling trends, suggesting that increasing greenhouse gases will benefit stratospheric ozone recovery. CCM simulations also show warming trends in stratospheric polar regions in the winter half-year for both hemispheres. According to previous studies, the polar warming is due to increasing planetary wave activity in the stratosphere. In addition, feedbacks among dynamical, thermal and chemical processes may also contribute the polar warming.
出处
《地球科学进展》
CAS
CSCD
北大核心
2009年第3期242-251,共10页
Advances in Earth Science
基金
国家自然科学基金面上项目"哈德雷环流强度和宽度的年代际变化"(编号:40875042)
国家自然科学基金重点项目"北极平流层异常对亚洲及北太平洋地区的天气气候影响研究"(编号:40533016)
教育部科学技术研究重点项目"冬季早期和晚期相反气候趋向的研究"(编号:106002)
教育部博士点基金项目"平流层异常对对流层天气系统的影响"(编号:20070001002)资助
关键词
平流层
气候变化
臭氧层恢复
温室气体增加
温室效应
Stratosphere
Climate change
Ozone recovery
Increasing greenhouse gases
Greenhouse effect.
