Model calculations of long-time changes in the middle and upper atmospheric chemical composition, temperature and circulation resulting from a changing Earth magnetic field

• Applicant: Dr. Miriam Sinnhuber
• Subject Area: Geophysics
• Term: from 2000 to 2007
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5250988

It is well known that the earth magnetic field changes its polarity in more or less frequent regular intervals. Typically such changes occur every 100.000 years, and have a duration of several thousand years. During such events the earth magnetic field is strongly reduced being less than 10% of its normal value. In addition during these periods magnetic field configurations of higher order (e.g. Quadrupoles) are expected. During periods of a reduced magnetic field strength, a much larger flux of extraterrestrial particles penetrate the atmosphere. (...)During periods having reduced and/or highly modified geo- magnetic field, extraterrestrial particles will penetrate lower into the atmosphere, and more importantly also reach regions where extraterrestrial particles are normally not found. (...)The research, proposed for this study will, extend existing atmospheric Chemical and Transport Models (CTM`s) to investi- gate and assess the impact and importance of changes in the earth`s magnetic field and the resultant increase in the amount, distributions and penetration of high energy particles in the atmosphere. In particular the modified global strato- spheric chemistry will be studied with one important emphasis being the estimation of the production rates of ozone depleting substances on a global scale. (...)

• DFG Programme: Priority Programmes
• Subproject of: SPP 1097: Geomagnetic Variations: Spatio-Temporal Structure, Processes, and Effects on System Earth
• Participating Persons: Professor Dr. John Philip Burrows; Professor Dr. Klaus F. Künzi; Professor Dr. Justus Notholt