کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1777919 | 1523678 | 2007 | 12 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Seasonal oscillations in mesospheric temperatures at low-latitudes Seasonal oscillations in mesospheric temperatures at low-latitudes](/preview/png/1777919.png)
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.
Journal: Journal of Atmospheric and Solar-Terrestrial Physics - Volume 69, Issues 17–18, December 2007, Pages 2367–2378