Climatology of the 630.0 and 557.7 nm emission over Arecibo Observatory based on 35 years of photometer data.

We are presenting the climatology of the 630.0 and 557.7 nm airglow emissions over the Arecibo Observatory based on 35 years of photometer data. The responses to solar and geomagnetic activity are evaluated as well as the long term trend of these emissions. The results will be compared to the electron density recorded by the 430Mhz Arecibo Incoherent Scatter Radar along the same period. Preliminary results show the decrease of 700m of the height of F2 peak layer along the last three decades as well as decrease in electron density.