Atmospheric changes caused by galactic cosmic rays over the period 1960-2010
Atmospheric changes caused by galactic cosmic rays over the period 1960-2010
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DOI：
10.5194/acp-16-5853-2016
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发表时间：
2016-01-01
影响因子：
6.3
通讯作者：
Fleming, Eric L.
中科院分区：
文献类型：
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作者：
Jackman, Charles H.;Marsh, Daniel R.;Fleming, Eric L.
利用全大气社区气候模式（SD-WACCM）和戈达德航天飞行中心二维（GSFC 2-D）模式研究了1960-2010年银河宇宙线（GCR）对大气的影响。在这些模拟中使用了用于航空安全的大气电离辐射的Nowcast（NAIRAS）计算GCR引起的电离率。在南极对流层中，计算出GCR引起的NOx最大增加4- 15 aEuro-%，相关臭氧增加1-2aEuro-%。计算出平流层下部的NOx增加量为1-6aEuro-%，臭氧减少量为0.2-1aEuro-%。GCR对臭氧的主要影响是由于其产生的NOx。大气氯负荷、硫酸盐气溶胶负荷和太阳活动周期变化对GCR的影响不同。由于NOx和ClOx臭氧损失循环之间的干扰（例如，ClO + NO2+aEuro-MaEuro- -> aEuro-ClONO 2 +aEuro-M反应）以及ClOx在臭氧收支中的重要性的变化，GCR以更少的氯负荷引起更大的大气影响。GCR还造成更大的大气影响，硫酸盐气溶胶负荷较少，多年来接近太阳极小期。GCR引起的年平均全球臭氧总量（AAGTO）的减少被计算为0.2aEuro-%或更少，GCR引起的1000和100 aEuro-hPa之间的气柱臭氧增加为0.08aEuro-%或更少，GCR引起的100和1aEuro-hPa之间的气柱臭氧减少为0.23aEuro-%或更少。GCR对臭氧产生自然影响，需要长期量化。这一结果作为一个下限，因为使用的电离模型NAIRAS/HZETRN低估了离子的产生忽略电磁和μ子分支的宇宙射线诱导级联。这将在今后的工作中得到纠正。
The Specified Dynamics version of the Whole Atmosphere Community Climate Model (SD-WACCM) and the Goddard Space Flight Center two-dimensional (GSFC 2-D) models are used to investigate the effect of galactic cosmic rays (GCRs) on the atmosphere over the 1960-2010 time period. The Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) computation of the GCR-caused ionization rates are used in these simulations. GCR-caused maximum NOx increases of 4-15aEuro-% are computed in the Southern polar troposphere with associated ozone increases of 1-2aEuro-%. NOx increases of similar to 1-6aEuro-% are calculated for the lower stratosphere with associated ozone decreases of 0.2-1aEuro-%. The primary impact of GCRs on ozone was due to their production of NOx. The impact of GCRs varies with the atmospheric chlorine loading, sulfate aerosol loading, and solar cycle variation. Because of the interference between the NOx and ClOx ozone loss cycles (e.g., the ClO + NO2+aEuro-MaEuro- -> aEuro-ClONO2+aEuro-M reaction) and the change in the importance of ClOx in the ozone budget, GCRs cause larger atmospheric impacts with less chlorine loading. GCRs also cause larger atmospheric impacts with less sulfate aerosol loading and for years closer to solar minimum. GCR-caused decreases of annual average global total ozone (AAGTO) were computed to be 0.2aEuro-% or less with GCR-caused column ozone increases between 1000 and 100aEuro-hPa of 0.08aEuro-% or less and GCR-caused column ozone decreases between 100 and 1aEuro-hPa of 0.23aEuro-% or less. Although these computed ozone impacts are small, GCRs provide a natural influence on ozone and need to be quantified over long time periods. This result serves as a lower limit because of the use of the ionization model NAIRAS/HZETRN which underestimates the ion production by neglecting electromagnetic and muon branches of the cosmic ray induced cascade. This will be corrected in future works.