All Physics Faculty Publications

Title

Seasonal Oscillations in Mesospheric Temperatures at Low-latitudes

Document Type

Article

Journal/Book Title/Conference

Journal of Atmospheric and Solar-Terrestrial Physics

Volume

69

Issue

17-18

Publisher

Elsevier

Publication Date

8-2007

First Page

2367

Last Page

2378

DOI

10.1016/j.jastp.2007.07.010

Abstract

Using 3 years of high-quality temperature measurements (2002–2004) recorded from Maui, HI (20.8°N), we have investigated the characteristics of mesospheric seasonal oscillations at low-latitudes. Measurements of the near-infrared OH (6,2) and O2 (0,1) nightglow emission layers (centered at ∼87 and ∼94 km) independently reveal a distinct semi-annual oscillation (SAO) and annual oscillation (AO) with amplitudes of ∼3.8 and ∼2.0 K, respectively. An observed asymmetry in the seasonal variation of the nocturnal mean, previously reported by Taylor et al. [2005. Characterization of the semi-annual-oscillation in mesospheric temperatures at low-latitudes. Advances in Space Research 35, doi:10.1016/j.asr.2005.05.111] from this site is shown to be due to a superposed AO of amplitude ∼50% of the SAO signature. Detailed investigations of the local-time variation of the SAO amplitude and phase combined with TIME-GCM simulations of the seasonal variation of the diurnal tide strongly suggest a large local-time dependence of the amplitude (but not phase) of the observed SAO. These data indicate that the true mean temperature SAO amplitude could be as high as ∼7 K at this latitude.

Comments

Published by Elsevier in Journal of Atmospheric and Solar-Terrestrial Physics.

http://www.sciencedirect.com/science/article/pii/S1364682607002258

Publisher PDF is available for download through the link above.

http://www.sciencedirect.com/science/article/pii/S1364682607002258