The 1356 intensity difference is systematically greater than the LBH intensity differences. The primary goal of this study is to examine the effect of altitude changes on emission ratios. The table below shows the pitch angles used, the resulting peak production rates, and the altitude of peak production. Changing the pitch angle from 54.8 to 0 degrees drops the altitude of peak production by 3 km. Peak Altitude for Different Values of Mean Cosine Pitch Angle.
Colored lines are for increasing pitch angle.
This is close to what is seen at 1 kev but the ratio changes significantly for higher energies. The additional difference is due, of course, to O2 absorption which is changing rapidly in this region. Since the changes in intensity ratios is not due to production rate changes, it must due to the changing effects of O2 attenuation over the altitude region of interest. In the figure below is plotted the column transmission rate to space, i.e. the percentage of photons, as a function of altitude, that are not absorbed by O2 absorption and could be detected by a nadir-viewing detector from space. One curve is plotted for each of the LBH bands.