Observations of lunar tides in upper atmosphere winds at Poker Flat, Alaska

Abstract Upper-atmosphere densities derived from photographic meteor decelerations were analyzed to probe the existence of detectable oscillations with periods corresponding to solar and lunar tides (and half-periods) and seasonal variations. Extensive fragmentation in meteors adds considerable difficulty to the analysis and makes empirical corrections necessary. The mean height of the analyzed meteors is 91.8 kilometers. A seasonal variation with an amplitude of 15 per cent of the mean density barely emerges from its probable error by a factor of two; tidal oscillations, if present, are masked by observational scatter and could not exceed 10 per cent of the mean density.

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Comparing the ionospheric response to the 2008/2009 and 2018/2019 SSW events

10.5194/egusphere-egu2020-18642 ◽

2020 ◽

Author(s):

Tarique Adnan Siddiqui ◽

Yosuke Yamazaki ◽

Claudia Stolle

Keyword(s):

Climate Model ◽

Lower Thermosphere ◽

Solar Flux ◽

Upper Atmosphere ◽

Lower Atmosphere ◽

Atmospheric Variability ◽

Vertical Coupling ◽

Lunar Tides ◽

Tidal Characteristics ◽

Coupling Mechanisms

<p>It is now well accepted that the ionosphere and thermosphere are sensitive to forcing from the lower atmosphere (troposphere-stratosphere) owing mainly to the progress that have been made in the last decade in understanding the vertical coupling mechanisms connecting these two distinct atmospheric regions. In this regard, the studies linking the upper atmosphere (mesosphere-lower thermosphere-ionosphere) variability due to sudden stratospheric warming (SSW) events have been particularly important. The change of stratospheric circulation due to SSW events modulate the spectrum of vertically upward propagating atmospheric waves (gravity waves, tides, and planetary waves) resulting in numerous changes in the state of the upper atmosphere. Much of our understanding about the upper atmospheric variability associated due to the SSWs events have been gained by studying the 2008/2009 SSW event, which occurred under extremely low solar flux conditions. Recently another SSW event in 2018/2019 occurred under similar low solar flux conditions. In this study we simulate both these SSW events using Whole Atmosphere Community Climate Model with thermosphere and ionosphere extension (WACCM-X) and present the findings by comparing the ionospheric and thermospheric response to both these SSW events. The tidal characteristics of the semidiurnal solar and lunar tides and the thermospheric composition for both these SSW events are compared and the causes of varying responses are investigated.</p>

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Measurements of the temperature and density of the upper atmosphere using artificial periodic irregularities during the summer seasons of 1999–2002

International Journal of Geomagnetism and Aeronomy ◽

10.1029/2004gi000061 ◽

2004 ◽

Vol 5 (1) ◽

Cited By ~ 11

Author(s):

A. V. Tolmacheva

Keyword(s):

Upper Atmosphere

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Influence of the upper atmosphere inhomogeneity on acoustic gravity wave propagation

Kosmìčna nauka ì tehnologìâ ◽

10.15407/knit2012.04.030 ◽

2012 ◽

Vol 18 (4(77)) ◽

pp. 30-36 ◽

Cited By ~ 1

Author(s):

Y.I. Kryuchkov ◽

◽

O.K. Cheremnykh ◽

A.K. Fedorenko ◽

◽

...

Keyword(s):

Wave Propagation ◽

Gravity Wave ◽

Upper Atmosphere ◽

Acoustic Gravity Wave

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Nitric oxide formation by meteoroids in the upper atmosphere

10.2514/6.1974-591 ◽

1974 ◽

Cited By ~ 2

Author(s):

G. MENEES ◽

C. PARK

Keyword(s):

Nitric Oxide ◽

Upper Atmosphere ◽

Oxide Formation ◽

Nitric Oxide Formation

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Comparison of the NASA Marshall engineering thermosphere model and the Russian upper atmosphere density model

10.2514/6.1995-554 ◽

1995 ◽

Author(s):

Steven Pavelitz ◽

B Anderson

Keyword(s):

Upper Atmosphere ◽

Density Model ◽

Atmosphere Density

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Space environment (natural and artificial). Earth upper atmosphere

10.3403/30244424 ◽

2013 ◽

Keyword(s):

Upper Atmosphere ◽

Space Environment ◽

Artificial Earth

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Could climate engineering save the Greenland Ice Sheet?

Climanosco Research Articles - https://www.climanosco.org/collection/climate-change-and-its-impacts/ ◽

10.37207/cra.1.10 ◽

2016 ◽

Author(s):

Patrick J. Applegate ◽

K. Keller

Keyword(s):

Sea Level Rise ◽

Greenhouse Gas Emissions ◽

Greenhouse Gas ◽

Sea Level ◽

Computer Model ◽

Ice Sheet ◽

Greenland Ice Sheet ◽

Upper Atmosphere ◽

Climate Engineering ◽

Air Temperatures

Engineering the climate through albedo modification (AM) could slow, but probably would not stop, melting of the Greenland Ice Sheet. Albedo modification is a technology that could reduce surface air temperatures through putting reflective particles into the upper atmosphere. AM has never been tested, but it might reduce surface air temperatures faster and more cheaply than reducing greenhouse gas emissions. Some scientists claim that AM would also prevent or reverse sea-level rise. But, are these claims true? The Greenland Ice Sheet will melt faster at higher temperatures, adding to sea-level rise. However, it's not clear that reducing temperatures through AM will stop or reverse sea-level rise due to Greenland Ice Sheet melting. We used a computer model of the Greenland Ice Sheet to examine its contributions to future sea level rise, with and without AM. Our results show that AM would probably reduce the rate of sea-level rise from the Greenland Ice Sheet. However, sea-level rise would likely continue even with AM, and the ice sheet would not regrow quickly. Albedo modification might buy time to prepare for sea-level rise, but problems could arise if policymakers assume that AM will stop sea-level rise completely.

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