Open AccessA model study of the temporal behaviour of the emission intensity and rotational temperature of the OH Meinel bands for high-latitude summer conditions
Author(s) -
M. J. López-González,
Donal Murtagh,
P. J. Espy,
J. J. LopezMoreno,
R. Rodrigo,
G. Witt
Publication year - 1996
Publication title -
annales geophysicae
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.522
H-Index - 93
eISSN - 1432-0576
pISSN - 0992-7689
DOI - 10.1007/s00585-996-0059-x
Subject(s) - mesopause , rotational temperature , latitude , atmospheric sciences , eddy diffusion , excited state , intensity (physics) , diffusion , materials science , analytical chemistry (journal) , environmental science , atomic physics , chemistry , spectral line , physics , mesosphere , meteorology , thermodynamics , optics , geology , turbulence , stratosphere , geodesy , astronomy , chromatography
The temporal variation of OH*emission and weighted rotational temperature has been studied for high-latitudesummer conditions. Observations for 60°N latitude show OH weighted temperaturesthat always exceed 145 K even during periods of noctilucent clouds. Using aone-dimensional model the effects in excited OH concentration produced bychanges in temperature, eddy diffusion, and water concentration have beenanalysed. We are forced to conclude that there remains a discrepancy between theOH temperatures predicted by the model and that obtained from OH*measurements. An increase in OH* concentration from June to thebeginning of August, followed by a slow decrease during August has been obtainedin agreement with the measurements. The 16-day modulation present in themeasurements was simulated in a simple manner by varying the temperature in themesopause region. This variation produces periodic modulations in both OH*concentration and weighted temperature of 16 days. The results show thetemperature leading the OH* column concentration by three days. Thisphase shift is also present in the observations