Testing of Solar2000 EUV flux model between 900-1350 A using Greenline Dayglow Emission

TL;DR

This study evaluates the Solar2000 V2.25 EUV flux model's accuracy in predicting greenline dayglow emissions between 92-105 km altitude, finding it generally improves upon previous models but requires refinement for mesospheric peaks.

Contribution

It provides a detailed comparison of the Solar2000 V2.25 model with WINDII observations, highlighting areas for model improvement in mesospheric emission predictions.

Findings

Solar2000 V2.25 model aligns well with observations at 92-96 km

Discrepancies exist in mesospheric peak regions

Reexamination of spectral line fluxes is recommended

Abstract

The contribution of photodissociation of molecular oxygen to the total volume emission rate of greenline dayglow emission at 5577 A is modelled in the present study. The Solar EUV radiation fluxes for the modelling are obtained from the Solar2000 V 2.25 model. The modelling has been done in the altitude range of 92 - 105 Km, where the photodissociation and the three body recombination are the main contributing processes to the greenline dayglow emission. The present results are discussed in the light of Wind Imaging Interferometer (WINDII) observations of greenline dayglow emission in the altitude range of 92 - 105 Km. It is found that the Solar2000 V2.25 flux model gives better agreement with the WINDII observations especially in the 92 - 96 Km where the earlier models predicted a very low emission rate. In the mesospheric emission peak region the present results are higher than the measurements and this discrepancy may possibly be attributed due to higher values of solar fluxes for those spectral lines which are main sources of the production of greenline dayglow emission. The present study suggests the reexamination of Solar2000 flux model at least for those spectral lines which are the main sources of greenline dayglow emission in mesospheric emission peak region.