Influence of Galactic Cosmic Rays on atmospheric composition and dynamics
Influence of Galactic Cosmic Rays on atmospheric composition and dynamics
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DOI：
10.5194/acp-11-4547-2011
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发表时间：
2011-01-01
影响因子：
6.3
通讯作者：
Peter, T.
中科院分区：
文献类型：
--
作者：
Calisto, M.;Usoskin, I.;Peter, T.
本文利用三维化学气候模式(CCM)SOCOL v2.0研究了银河宇宙线(GCRs)对大气成分、温度和动力学的影响。电离率根据CRAC：CRII(宇宙射线诱导级联：宇宙线诱导电离的应用)进行参数化，这是一个详细的最先进模型，描述了从0-80公里的CCM整个高度范围内的GCR效应。我们发现GCRs对对流层和平流层NOx、Hox、臭氧、温度和纬向风的影响是统计上显著的，而NOx、Hox和臭氧是年平均的，温度和纬向风是月平均的。在南半球，模式表明GCR引起的NOx在对流层顶区增加超过10%(在极点达到20%的峰值)，而Hox显示出大约3%的减少，这是由于增强转化为HNO3引起的。因此，臭氧在相对未受污染的南部对流层增加了高达3%，那里的臭氧产生对来自GCRs的额外NOx很敏感。相反，在北极低平流层，GCR被发现使O-3减少了3%，这是由于在GCR诱导产生ClONO2之后，通过ClONO2+HCl进行的额外的异质氯活化所致。2月份北半球40公里以下的纬向风存在明显的GCR诱发的5m S(-1)加速，在较高海拔出现减速，峰值可达3m S(-1)，高度在70公里左右。该模式还确认了GCR引起的地面空气变化，欧洲东部和俄罗斯变暖(3月份的值高达2.25K)，西伯利亚和格陵兰的降温(近2K)。我们发现，即使只在18公里以上考虑GCR诱导的电离，这些表面温度的变化也会发生，这表明极地夜间急流的平流层驱动的加强一直延伸到地球表面。
This study investigates the influence of the Galactic Cosmic Rays (GCRs) on the atmospheric composition, temperature and dynamics by means of the 3-D Chemistry Climate Model (CCM) SOCOL v2.0. Ionization rates were parameterized according to CRAC:CRII (Cosmic Ray induced Cascade: Application for Cosmic Ray Induced Ionization), a detailed state-of-the-art model describing the effects of GCRs in the entire altitude range of the CCM from 0-80 km. We find statistically significant effects of GCRs on tropospheric and stratospheric NOx, HOx, ozone, temperature and zonal wind, whereas NOx, HOx and ozone are annually averaged and the temperature and the zonal wind are monthly averaged. In the Southern Hemisphere, the model suggests the GCR-induced NOx increase to exceed 10% in the tropopause region (peaking with 20% at the pole), whereas HOx is showing a decrease of about 3% caused by enhanced conversion into HNO3. As a consequence, ozone is increasing by up to 3% in the relatively unpolluted southern troposphere, where its production is sensitive to additional NOx from GCRs. Conversely, in the northern polar lower stratosphere, GCRs are found to decrease O-3 by up to 3 %, caused by the additional heterogeneous chlorine activation via ClONO2 + HCl following GCR-induced production of ClONO2. There is an apparent GCR-induced acceleration of the zonal wind of up to 5 m s(-1) in the Northern Hemisphere below 40 km in February, and a deceleration at higher altitudes with peak values of 3 m s(-1) around 70 km altitude. The model also indentifies GCR-induced changes in the surface air, with warming in the eastern part of Europe and in Russia (up to 2.25 K for March values) and cooling in Siberia and Greenland (by almost 2 K). We show that these surface temperature changes develop even when the GCR-induced ionization is taken into account only above 18 km, suggesting that the stratospherically driven strengthening of the polar night jet extends all the way down to the Earth's surface.