On the interaction between gravity waves and the OH Meinel (6-2) and the O2atmospheric (0-1) bands in the polar night airglow

1989 ◽  
Vol 94 (A5) ◽  
pp. 5397 ◽  
Author(s):  
R. A. Viereck ◽  
C. S. Deehr
2021 ◽  
Author(s):  
Andreas Dörnbrack

<table><tbody><tr><td> <p><span>Planetary waves disturbed the hitherto stable Arctic stratospheric polar vortex mid of<br>January 2016 in such a way that unique tropospheric and stratospheric flow conditions<br>for vertically and horizontally propagating mountain waves developed. Co-existing<br>strong low-level westerly winds across almost all European mountain ranges plus the<br>almost zonally-aligned polar front jet created these favorable conditions for deeply<br>propagating gravity waves. Furthermore, the northward displacement of the polar night<br>jet resulted in a wide-spread coverage of stratospheric mountain waves trailling across<br>northern Europe. This paper describes the particular meteorological setting by<br>analyzing the tropospheric and stratospheric flows based on the ERA5 data. The<br>potential of the flow for exciting internal gravity waves from non-orographic sources is<br>evaluated across all altitudes by considering various instability indices as δ , Ro, Ro ζ , Ro<sub>⊥</sub> ,<br>and Δ NBE</span><span>. </span></p> <p><span>The analyzed gravity waves are described and characterized in terms of<br>commonly used parameters. The main finding of this case study is the exceptionally<br>vast extension of the mountain waves trailing to high latitudes originating from the flow<br>across the mountainous sources that are located at about 45 N. As a useful addition to<br>the case study, tracks for potential research flights are proposed that sample the<br>waves by a vertically pointing airborne remote-sensing instrument. Benefits and<br>drawbacks of the different approaches to observe the meridional focussing of the<br>mountain waves into the polar night jet are discussed.</span></p> </td> </tr></tbody></table><p> </p>


2020 ◽  
Vol 125 (21) ◽  
Author(s):  
Katrina Bossert ◽  
Sharon L. Vadas ◽  
Lars Hoffmann ◽  
Erich Becker ◽  
V. Lynn Harvey ◽  
...  
Keyword(s):  

Author(s):  
Tyler Mixa ◽  
Andreas Dörnbrack ◽  
Markus Rapp

AbstractHorizontally dispersing gravity waves with horizontal wavelengths of 30 – 40 km were observed at mesospheric altitudes over Auckland Island by the airborne advanced mesospheric temperature mapper during a DEEPWAVE research flight on 14 July 2014. A 3D nonlinear compressible model is used to determine which propagation conditions enabled gravity wave penetration into the mesosphere and how the resulting instability characteristics led to widespread momentum deposition. Results indicate that linear tunneling through the polar night jet enabled quick gravity wave propagation from the surface up to the mesopause, while subsequent instability processes reveal large rolls that formed in the negative shear above the jet maximum and led to significant momentum deposition as they descended. This study suggests that gravity wave tunneling is a viable source for this case and other deep propagation events reaching the mesosphere and lower thermosphere.


2020 ◽  
Vol 9 (4) ◽  
pp. 35-43
Author(s):  
Chris Ingraham

Drawing from in situ fieldwork in Longyearbyen, Svalbard, the northernmost settlement on Earth, these notes bring out the affective, ambient, and atmospheric power of extended darkness during the polar night, when the sun does not appear above the horizon for several months at a time. Each entry is composed of 113 words to reflect the number of days without light in Longyearbyen during the winter of my visit. Through a mixture of ethnographic observations, researched academic scholarship, and some endeavors of poetic worldmaking, these notes attempt to evoke the ineffable force of global warming by performing the sort of acutely observed and felt attentiveness to planetary being that is needed for our time.


2001 ◽  
Vol 7 (2s) ◽  
pp. 26-33 ◽  
Author(s):  
O.E. Gotynyan ◽  
◽  
V.N. Ivchenko ◽  
Yu.G. Rapoport ◽  
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...  

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