Numerical simulation of the atmospheric ionization and the generation of cosmogenic nuclides for different topologies of the geomagnetic field

不同地磁场拓扑下大气电离和宇宙成因核素产生的数值模拟

• 批准号: 5249030
• 负责人: Professorin Dr. May-Britt Kallenrode
• 金额: --
• 依托单位: Präsidium
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2000
• 资助国家: 德国
• 起止时间: 1999-12-31 至 2009-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5249030?language=en
• 关键词: Numerical; simulation; atmospheric; ionization; generation

Cosmics rays of solar and galactic origin partly are screened off from the Earth's surface by two filters, the magnetosphere and the atmosphere. The terrestrial magnetic field is known to be quite variable on different time scales. The field and its variability, which is most obvious in magnetic field reversals accompanied by dramatic decrease in the magnetic field strength, originates in a magnetohydrodynamic dynamo process inside Earth's core. Changes in the geomagnetic field modify the access of energetic particles to the lower atmosphere, altering the generation of cosmogenic nuclides such as 10Be and 14C as well as the ionization of the mid-atmosphere caused. In this study we will develop a model combining the particle propagation in a geomagnetic field of different strenghts and topologies and the particle interaction with the atmosphere to determine (a) the generation of cocmogenic nuclides and (b) the ionization caused by the energetic particles for different topologies/strengths of the geomagnetic field. The results of this study can be used as additional tests for dynamo models and as an input to determine atmospheric changes, such as the ozone content or the global circuit, for different states of the geomagnetic field.

来自太阳和银河系的宇宙射线部分被地球表面的两个过滤器，即磁层和大气层屏蔽掉。地球磁场在不同的时间尺度上变化很大。磁场及其变化，这是最明显的磁场逆转伴随着磁场强度急剧下降，起源于磁流体动力学发电机过程内的地球核心。地磁场的变化改变了高能粒子进入低层大气的途径，改变了宇宙成因核素（如10 Be和14 C）的生成以及造成的中层大气电离。在这项研究中，我们将开发一个模型相结合的粒子在不同的强度和拓扑结构的地磁场和粒子与大气的相互作用，以确定（a）的cocmogenic核素的产生和（B）的电离所造成的高能粒子不同的拓扑结构/地磁场的强度。这项研究的结果可用作发电机模型的额外测试，并作为确定大气变化的输入，如臭氧含量或全球电路，地磁场的不同状态。