Influence of the Earth's diurnal rotation on the propagation of large-scale disturbances in the upper atmosphere

2007 ◽  
Author(s):  
Nataly P. Perevalova ◽  
Edward L. Afraimovich ◽  
Sergey V. Voeykov ◽  
Ilya V. Zhivetiev
Keyword(s):  
Large Scale ◽  
Upper Atmosphere ◽  
Diurnal Rotation

Search for helium in the upper atmosphere of the hot Jupiter WASP-127 b using Phoenix/Gemini

2020 ◽  
Author(s):  
Leonardo A. dos Santos ◽  
David Ehrenreich ◽  
Vincent Bourrier ◽  
Romain Allart ◽  
George King ◽  
...  
Keyword(s):  
Large Scale ◽  
High Energy ◽  
Upper Atmosphere ◽  
Metastable Helium ◽  
Atmospheric Escape ◽  
Short Period ◽  
Energy Environment ◽  
In Transit ◽  
First Time ◽  
Hot Jupiter

<div class="page" title="Page 1"> <div class="layoutArea"> <div class="column"> <p>Large-scale exoplanet search surveys have shown evidence that atmospheric escape is a ubiquitous process that shapes the evolution and demographics of planets. However, we lack a detailed understanding of this process because very few exoplanets discovered to date could be probed for signatures of atmospheric escape. Recently, the metastable helium triplet at 1.083 μm has been shown to be a viable window for the presence of He-rich escaping envelopes around short-period exoplanets. Our objective is to use, for the first time, the Phoenix spectrograph to search for helium in the upper atmosphere of the inflated hot Jupiter WASP-127 b. We observed one transit and reduced the data manually since there is no pipeline available. We did not find a significant in-transit absorption signal indicative of the presence of helium around WASP-127 b, and set a 90% confidence upper limit for excess absorption at 0.87% in a 0.75 Å passband covering the He triplet. Given the large scale height of this planet, the lack of a detectable feature is likely due to unfavorable photoionization conditions to populate the metastable He I triplet. This conclusion is supported by the inferred low coronal and chromospheric activity of the host star and the old age of the system, which result in a relatively mild high-energy environment around the planet.</p> </div> </div> </div>

The Historic Search for Red Sprites: Art Meets Science in Lightning's Angels

Leonardo ◽  
2005 ◽  
Vol 38 (2) ◽  
pp. 109-114
Author(s):  
Peter McLeish
Keyword(s):  
Large Scale ◽  
Upper Atmosphere ◽  
Natural Phenomenon ◽  
Visual Images ◽  
Red Sprites ◽  
Digitally Enhanced

Sprites are fleeting, luminous shapes that shoot into the upper atmosphere during large thunderstorms as lightning simultaneously reaches down to Earth. For at least a century, scientists have attempted to confirm and explain the existence of sprites with visual images and data. The author's series Lightning's Angels supplements the documentation of sprites by exploring the properties of this natural phenomenon through digitally enhanced oil portraits set to music and displayed in a large scale multimedia format, such as at a planetarium.

Whole Atmosphere Coupling during the September 2019 Antarctic Sudden Stratospheric Warming

2021 ◽  
Author(s):  
Yosuke Yamazaki ◽  
Yasunobu Miyoshi
Keyword(s):  
Large Scale ◽  
Lower Thermosphere ◽  
Upper Atmosphere ◽  
The Arctic ◽  
Electron Content ◽  
Stratospheric Warming ◽  
Sudden Stratospheric Warming ◽  
Total Electron ◽  
Total Electron Content Data ◽  
Zonal Wavenumber

<p>A sudden stratospheric warming (SSW) is a large-scale meteorological phenomenon, which is most commonly observed in the Arctic region during winter months. In September 2019, a rare SSW occurred in the Antarctic region, providing a unique opportunity to study its impact on the middle and upper atmosphere. Geopotential height measurements by the Microwave Limb Sounder aboard NASA's Aura satellite reveal a burst of westward-propagating quasi-6-day wave (Q6DW) with zonal wavenumber 1 in the mesosphere and lower thermosphere following the SSW. At this time, ionospheric data from ESA's Swarm satellite constellation mission show prominent 6-day variations in the daytime equatorial electrojet intensity and low-latitude plasma densities. The whole atmosphere model GAIA reproduces salient features of the middle and upper atmosphere response to the SSW. GAIA results suggest that the observed ionospheric 6-day variations are not directly driven by the Q6DW but driven indirectly through tidal modulations by the Q6DW. An analysis of global total electron content data reveals signatures of secondary waves arising from the nonlinear interaction between the Q6DW and tides.</p>

scholarly journals Electromagnetic oscillations of the Earth's upper atmosphere (review)

2010 ◽  
Vol 28 (7) ◽  
pp. 1387-1399 ◽  
Author(s):  
A. G. Khantadze ◽  
G. V. Jandieri ◽  
A. Ishimaru ◽  
T. D. Kaladze ◽  
Zh. M. Diasamidze
Keyword(s):  
Gravity Waves ◽  
Geomagnetic Field ◽  
Large Scale ◽  
Low Frequency ◽  
Planetary Waves ◽  
Upper Atmosphere ◽  
Acoustic Gravity Waves ◽  
Weakly Ionized ◽  
General Dispersion ◽  
Electromagnetic Oscillations

Abstract. A complete theory of low-frequency MHD oscillations of the Earth's weakly ionized ionosphere is formulated. Peculiarities of excitation and propagation of electromagnetic acoustic-gravity, MHD and planetary waves are considered in the Earth's ionosphere. The general dispersion equation is derived for the magneto-acoustic, magneto-gravity and electromagnetic planetary waves in the ionospheric E- and F-regions. The action of the geomagnetic field on the propagation of acoustic-gravity waves is elucidated. The nature of the existence of the comparatively new large-scale electromagnetic planetary branches is emphasized.

scholarly journals What can large-scale magnetohydrodynamic numerical experiments tell us about coronal heating?

2015 ◽  
Vol 373 (2042) ◽  
pp. 20150055 ◽  
Author(s):  
H. Peter
Keyword(s):  
Magnetic Field ◽  
Numerical Experiments ◽  
Large Scale ◽  
Extreme Ultraviolet ◽  
Complex Structure ◽  
Three Dimensional ◽  
Upper Atmosphere ◽  
Good Representation ◽  
The Sun ◽  
Coronal Emission

The upper atmosphere of the Sun is governed by the complex structure of the magnetic field. This controls the heating of the coronal plasma to over a million kelvin. Numerical experiments in the form of three-dimensional magnetohydrodynamic simulations are used to investigate the intimate interaction between magnetic field and plasma. These models allow one to synthesize the coronal emission just as it would be observed by real solar instrumentation. Large-scale models encompassing a whole active region form evolving coronal loops with properties similar to those seen in extreme ultraviolet light from the Sun, and reproduce a number of average observed quantities. This suggests that the spatial and temporal distributions of the heating as well as the energy distribution of individual heat deposition events in the model are a good representation of the real Sun. This provides evidence that the braiding of fieldlines through magneto-convective motions in the photosphere is a good concept to heat the upper atmosphere of the Sun.

scholarly journals Search for helium in the upper atmosphere of the hot Jupiter WASP-127 b using Gemini/Phoenix

2020 ◽  
Vol 640 ◽  
pp. A29 ◽  
Author(s):  
Leonardo A. dos Santos ◽  
David Ehrenreich ◽  
Vincent Bourrier ◽  
Romain Allart ◽  
George King ◽  
...  
Keyword(s):  
Large Scale ◽  
High Energy ◽  
Upper Atmosphere ◽  
Metastable Helium ◽  
Atmospheric Escape ◽  
Short Period ◽  
Energy Environment ◽  
In Transit ◽  
First Time ◽  
Hot Jupiter

Large-scale exoplanet search surveys have shown evidence that atmospheric escape is a ubiquitous process that shapes the evolution and demographics of planets. However, we lack a detailed understanding of this process because very few exoplanets that have been discovered to date could be probed for signatures of atmospheric escape. Recently, the metastable helium triplet at 1.083 μm has been shown to be a viable window for the presence of He-rich escaping envelopes around short-period exoplanets. Our objective is to use, for the first time, the Phoenix spectrograph to search for helium in the upper atmosphere of the inflated hot Jupiter WASP-127 b. We observed one transit and reduced the data manually since no pipeline is available. We did not find a significant in-transit absorption signal indicative of the presence of helium around WASP-127 b, and we set a 90% confidence upper limit for excess absorption at 0.87% in a 0.75 Å passband covering the He triplet. Given the large scale height of this planet, the lack of a detectable feature is likely due to unfavorable photoionization conditions for populating the metastable He I triplet. This conclusion is supported by the inferred low coronal and chromospheric activity of the host star and the old age of the system, which result in a relatively mild high-energy environment around the planet.

Vertical Atmospheric Coupling during the September 2019 Antarctic Sudden Stratospheric Warming

2020 ◽  
Author(s):  
Yosuke Yamazaki ◽  
Vivien Matthias ◽  
Yasunobu Miyoshi ◽  
Claudia Stolle ◽  
Tarique Siddiqui ◽  
...  
Keyword(s):  
Large Scale ◽  
Middle Atmosphere ◽  
Lower Thermosphere ◽  
Upper Atmosphere ◽  
The Arctic ◽  
Electron Content ◽  
Stratospheric Warming ◽  
Sudden Stratospheric Warming ◽  
Total Electron ◽  
Zonal Wavenumber

<p>A sudden stratospheric warming (SSW) is an extreme wintertime meteorological phenomenon occurring mostly over the Arctic region. Studies have shown that an Arctic SSW can influence the whole atmosphere including the ionosphere. In September 2019, a rare SSW event occurred in the Antarctic region, following strong wave-1 planetary wave activity. The event provides an opportunity to investigate its broader impact on the upper atmosphere, which has been largely unexplored in previous studies. Ionospheric data from ESA's Swarm satellite constellation mission show prominent 6-day variations in the dayside low-latitude region during the SSW, including 20-70% variations in the equatorial zonal electric field, 20-40% variations in the electron density, and 5-10% variations in the top-side total electron content. These ionospheric variations have characteristics of a westward-propagating wave with zonal wavenumber 1, and can be attributed to forcing from the middle atmosphere by the Rossby normal mode “quasi-6-day wave” (Q6DW). Geopotential height measurements by the Microwave Limb Sounder aboard NASA's Aura satellite reveal a burst of global Q6DW activity in the mesosphere and lower thermosphere at this time, which is one of the strongest in the record. These results suggest that an Antarctic SSW can lead to ionospheric variability by altering middle atmosphere dynamics and propagation characteristics of large-scale waves from the middle atmosphere to the upper atmosphere.</p>

upper atmosphere investigations require coordinated approach

1967 ◽  
Vol 48 (4) ◽  
pp. 262-264 ◽  
Author(s):  
Sidney Teweles
Keyword(s):  
Large Amplitude ◽  
Large Scale ◽  
Lower Thermosphere ◽  
Upper Atmosphere ◽  
Aerospace Vehicles ◽  
Indirect Methods ◽  
Orbital Decay ◽  
Mesosphere And Lower Thermosphere

The atmospheric layers from 60 to 200 km above the Earth's surface can be sounded only by expensive rocket-launched experiments, problematical indirect methods, or satellites in rapid orbital decay. Measurements of large-scale phenomena are masked by large amplitude perturbations, both aperiodic and tidal. Still the needs of the rapidly increasing traffic of aerospace vehicles through this region must be served. There is a growing requirement for meteorologists to apply their special skills to the analysis of the costly data now accumulating in substantial amounts from the mesosphere and lower thermosphere.

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