关键词: 平流层, 气候变化, 温室气体, 臭氧, 典型浓度路径

Abstract:

When studying stratospheric climate change in the 21st century, it is a critically important question that how stratospheric temperatures are changed by the two opposite forcings, which are stratospheric warming due to ozone recovery and stratospheric cooling due to increasing greenhouse gases. To illustrate this, CMIP5 simulations are employed to calculate stratospheric temperature trends over the period of 2006?2100. The results show that the warming effect of stratospheric ozone recovery plays the main role in the lower stratosphere, while the cooling effect of increasing greenhouse gases is more important in middle and upper stratosphere. As a result, the lower stratosphere is dominated by warming trends, whereas the middle and upper stratosphere is dominated by cooling trends. As CMIP5 models are separated into high-top and low-top groups, it is found that high-top models, which have model-top above the stratopause and have more realistic stratospheric physical and dynamic processes, generate stronger warming than low-top models do. It implies that a well-resolved stratosphere likely has a significant effects on simulating temperature trends in the 21st century both in troposphere and stratosphere.

Key words: stratosphere, climate change, greenhouse gases, ozone, representative concentration pathway