Note that the subscript notation forced an undesirable spacing upon this report and was thus not used.
Ben Walker
Solar Rotation Effects on The
Thermospheres of Mars and Earth
The first thing that must be understood in this paper is the chain of events that is being tracked. From the Sun's rotational quirks, to their effects on CO2 in the respective atmospheres of Mars and Earth. There is also a comparison to older, normalized data from Venus.
Unlike the planets which orbit it, the Sun's rotation is not even. At the poles, the magnetic forces rotate every 25 days; while at the equator, the magnetic field rotates ever 35 days. This discrepancy causes twist in the magnetic field. This twist is the cause of sunspots and solar flares. It also is highly correlated with the production of extreme ultraviolet light, such as that in the 10cm radio band. The twist in the magnetic field has a period of approximately 27 days. However there is a high standard deviation from this period (measured in days,) and as such it is often called a quasi-period. [2]
This extreme ultraviolet light (EUV) is dispersed by the outer atmosphere, by being transfered to light. It was thought that the quantity of CO2 in the atmosphere was the key factor in determining the diffusion rate. The paper analyses this concept to further detail. There is some detail given to the normalization process by which radiation recieved on Earth from Mars is adjusted (both temporally and spatially) so that it correlates with the same 27 day period of solar activity. Most of this is simple to perform, as we know the decay rate of the 10.7 cm EUV (from experimentation) as well as the time it would take for it to reach Mars and for the thermal changes to be evident. The data taken from Venus was merely normalized (Temperature'/EUV') and compared with a similar normalization to Earth and Mars. This does assume a linear correlation between EUV and temperature changes, however the current data does suggest that kind of correlation within the observed envelope of EUV. [1,3]
Interestingly, once the data was compiled, there was no correlation found between the levels of CO2 found in the upper atmosphere (~150km on Earth, where this transformation takes place.) Broadening their search, the authors found a strong correlation between the ratio of CO2/O2 and the thermal changes. They feel this suggests that the thermal diffusion effect relies on some form of resonance between the two molecules involved. They of course recommend studies to see if this diffusion effect can be controlled in a labratory setting by adjusting the ratio of the two gasses. [1]
Bibliography
[1] Solar Rotation Effects on the Thermospheres of Mars and Earth (June 2006.) Jeffrey Forbes et all. Science Magazine.
[2] Sun’s Magnetic Field, http://www-nutev.phyast.pitt.edu/~naples/class/, retrieved Jan 2007.
[3] 10cm Solar Radio Flux, http://www.ips.gov.au/ Educational/2/2/5, retrieved Jan 2007.
[2] Sun’s Magnetic Field, http://www-nutev.phyast.pitt.edu/~naples/class/, retrieved Jan 2007.
[3] 10cm Solar Radio Flux, http://www.ips.gov.au/ Educational/2/2/5, retrieved Jan 2007.