Modeling of 8446 A dayglow emission in the northern hemisphere

The atomic oxygen OI 8446 A emission is a prominent airglow feature observed in the thermosphere. This emission has a long observational history in twilight and aurora. This emission is very useful in understanding the varying levels of atomic oxygen concentration at these altitudes. A comprehensive model is developed to study the 8446 A dayglow emission incoporating different production processes. The emission profiles are obtained with the help of recently developed Solar2000 EUV (Extreme Ultra Violet) flux model also known as Solar Irradiance Platform. A span of five years (2001-2005) is chosen to study the effect of solar activity on this emission. The emission is modeled for April 3 which lies under equinox conditions. In the year 2001 the solar F10.7 index on the chosen date was as high as 223.1 which is the case of solar maximum. The F10.7 variation during the mentioned five year period is between 223 and 80, this window gives an opportunity to study this emission for different solar activity conditions. It is found that the intensity does not vary linearly with the F10.7 solar index. The OI 8446 A emission is found to be very sensitive to the solar activity. The results of modeling of yearly and diurnal variation of volume emission rate and intensity at different locations in the northern hemisphere are discussed.