Night airglow zenith intensity variations at El Leoncito Observatory, Argentina

Abstract

Seasonal and diurnal variations for [O I] λ5577 A, [O I] λ6300 A, and NaI λλ5890–5896 A emissions during 1967 are reported. The southern hemisphere station results for λ5577 and λ6300 emissions are similar to results reported from a northern hemisphere tropical station. The λ6300 emission variation is in phase for both hemispheres. The λλ5890–5896 emission variation is seasonal, the primary maximum being in the fall and the secondary maximum being in the spring, i.e., 6 months out of phase for both hemispheres. The suggested connection between the λ6300 emission intensity fluctuations and electric fields in the F layer is strengthened.

Sodium nightglow measurements and implications on the sodium photochemistry

“…In practice therefore the R branch intensity is taken as the base line for the be more pronounced than the spring one. This is consistent with previously published southern hemisphere results [Ciner and Smith, 1973], although those data were not properly corrected for the OH contamination. This is also true for northern hemisphere results.…”

“…It seems very likely, then, that the postmidnight increase in sodium emission is also caused by the semidiurnal solar tide.The seasonal variation is similar to that at other latitudes. ßAs was previously reported [Wiens and Weill, 1973;Ciner and Smith, 1973] there is a 6-month time lag between northern and southern hemisphere variations, the spring equinox peak almost vanishing at high latitudes.…”