Latitudinal dependence of low cloud amount on cosmic ray induced ionization
Latitudinal dependence of low cloud amount on cosmic ray induced ionization
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DOI：
10.1029/2004gl019507
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发表时间：
2004-07
影响因子：
5.2
通讯作者：
I. Usoskin;N. Marsh;G. Kovaltsov;K. Mursula;O. Gladysheva
中科院分区：
文献类型：
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作者：
I. Usoskin;N. Marsh;G. Kovaltsov;K. Mursula;O. Gladysheva
最近发现，过去 20 年来每年的宇宙射线通量与低层云的数量之间存在显着的相关性。然而，所提出的物理解释尚未通过建模和实验相结合在大气中得到定量验证。在这里，我们研究了观测到的低云量的全局分布与计算出的宇宙射线引起的对流层电离之间的关系。我们发现低云量的时间演化可以分解为长期趋势和年际变化，后者描绘出清晰的11年周期。我们还发现，低云量的相对年际变化向极地方向增加，并与 20-55°S 和 10-70°N 纬度范围内电离的年际变化呈现出高度显着的一对一关系。这种纬度依赖性有力地支持了宇宙射线诱导电离调节云特性的假设。
A significant correlation between the annual cosmic ray flux and the amount of low clouds has recently been found for the past 20 years. However, of the physical explanations suggested, none has been quantitatively verified in the atmosphere by a combination of modelling and experiment. Here we study the relation between the global distributions of the observed low cloud amount and the calculated tropospheric ionization induced by cosmic rays. We find that the time evolution of the low cloud amount can be decomposed into a long‐term trend and inter‐annual variations, the latter depicting a clear 11‐year cycle. We also find that the relative inter‐annual variability in low cloud amount increases polewards and exhibits a highly significant one‐to‐one relation with inter‐annual variations in the ionization over the latitude range 20–55°S and 10–70°N. This latitudinal dependence gives strong support for the hypothesis that the cosmic ray induced ionization modulates cloud properties.