Simulation of recent northern winter climate trends by greenhouse-gas forcing
Simulation of recent northern winter climate trends by greenhouse-gas forcing
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DOI：
10.1038/20905
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发表时间：
1999-06
期刊：
影响因子：
64.8
通讯作者：
D. Shindell;Ronald L. Miller;G. Schmidt;L. Pandolfo
中科院分区：
文献类型：
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作者：
D. Shindell;Ronald L. Miller;G. Schmidt;L. Pandolfo
在过去的一个世纪里，地球表面的空气温度有所上升，但人为温室气体造成的变暖比例仍然存在争议。冬季北半球陆地的变暖趋势最强烈，与大气环流的变化密切相关。这些环流变化表现为高纬度海平面压力逐渐减少，以及与北极涛动（北大西洋涛动的半球规模版本）的一个阶段相关的中纬度海平面压力的增加。在这里，我们使用几种不同的气候模型版本来证明观察到的海平面压力趋势（包括其大小）可以通过温室气体浓度的实际增加来模拟。因此，虽然变暖是通过自然发生的大气变化模式出现的，但它可能是人为引起的，并且可能会继续上升。北极涛动趋势仅在包含平流层真实表现的气候模型中捕获，而臭氧浓度的变化对于模拟观测到的气候趋势而言并不必需。平流层动力学的正确表示对于气候变化的归因似乎很重要，至少在广泛的区域范围内是如此。
The temperature of air at the Earth's surface has risen during the past century, but the fraction of the warming that can be attributed to anthropogenic greenhouse gases remains controversial. The strongest warming trends have been over Northern Hemisphere land masses during winter, and are closely related to changes in atmospheric circulation. These circulation changes are manifested by a gradual reduction in high-latitude sea-level pressure, and an increase in mid-latitude sea-level pressure associated with one phase of the Arctic Oscillation (a hemisphere-scale version of the North Atlantic Oscillation). Here we use several different climate-model versions to demonstrate that the observed sea-level-pressure trends, including their magnitude, can be simulated by realistic increases in greenhouse-gas concentrations. Thus, although the warming appears through a naturally occurring mode of atmospheric variability, it may be anthropogenically induced and may continue to rise. The Arctic Oscillation trend is captured only in climate models that include a realistic representation of the stratosphere, while changes in ozone concentrations are not necessary to simulate the observed climate trends. The proper representation of stratospheric dynamics appears to be important to the attribution of climate change, at least on a broad regional scale.