Propagating characteristics of mesospheric gravity waves observed by an OI 557.7 nm airglow all-sky camera at Mt. Bohyun (36.2° N, 128.9° E)
<p>We analysed all-sky camera images observed at Mt. Bohyun observatory (36.2<span class="inline-formula"><sup>∘</sup></span> N, 128.9<span class="inline-formula"><sup>∘</sup></span> E) for the period 2017–2019. The image data...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2022-05-01
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| Series: | Annales Geophysicae |
| Online Access: | https://angeo.copernicus.org/articles/40/247/2022/angeo-40-247-2022.pdf |
| Summary: | <p>We analysed all-sky camera images observed at Mt. Bohyun observatory (36.2<span class="inline-formula"><sup>∘</sup></span> N, 128.9<span class="inline-formula"><sup>∘</sup></span> E) for the period 2017–2019. The image
data were acquired with a narrowband filter centred at 557.7 <span class="inline-formula">nm</span> for the OI airglow emission at <span class="inline-formula">∼</span> 96 <span class="inline-formula">km</span> altitude. A total of
150 wave events were identified in the images of 144 clear nights. The interquartile ranges of wavelength, phase speed and periods of the
identified waves are 20.5–35.5 <span class="inline-formula">km</span>, 27.4–45.0 <span class="inline-formula">m s<sup>−1</sup></span> and 10.8–13.7 <span class="inline-formula">min</span> with the median values of 27.8 <span class="inline-formula">km</span>,
36.3 <span class="inline-formula">m s<sup>−1</sup></span> and 11.7 <span class="inline-formula">min</span>, respectively. The summer and spring bias of propagation directions of north-eastward and northward,
respectively, can be interpreted as the effect of filtering by the prevailing winds in the lower atmosphere. In winter the subdominant
north-westward waves may be observed due to a nullified filtering effect by slow northward background wind or secondary waves generated in the upper
atmosphere. Intrinsic phase speeds and periods of the waves were also derived by using the wind data simultaneously observed by a nearly co-located
meteor radar. The nature of vertical propagation was evaluated in each season. The majority of observed waves are found to be freely propagating
and thus can be attributed to wave sources in the lower or upper atmosphere.</p> |
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| ISSN: | 0992-7689 1432-0576 |