Topic
Atmospheric waveguide
About: Atmospheric waveguide is a research topic. Over the lifetime, 26 publications have been published within this topic receiving 373 citations.
Papers
TL;DR: In this article, a specific fingerprint in the zonal mean surface temperature profile that is associated with quasi-resonant amplification of synoptic-scale waves with that wavenumber range becoming trapped within an effective mid-latitude atmospheric waveguide was identified.
Abstract: Persistent episodes of extreme weather in the Northern Hemisphere summer have been shown to be associated with the presence of high-amplitude quasi-stationary atmospheric Rossby waves within a particular wavelength range (zonal wavenumber 6–8). The underlying mechanistic relationship involves the phenomenon of quasi-resonant amplification (QRA) of synoptic-scale waves with that wavenumber range becoming trapped within an effective mid-latitude atmospheric waveguide. Recent work suggests an increase in recent decades in the occurrence of QRA-favorable conditions and associated extreme weather, possibly linked to amplified Arctic warming and thus a climate change influence. Here, we isolate a specific fingerprint in the zonal mean surface temperature profile that is associated with QRA-favorable conditions. State-of-the-art (“CMIP5”) historical climate model simulations subject to anthropogenic forcing display an increase in the projection of this fingerprint that is mirrored in multiple observational surface temperature datasets. Both the models and observations suggest this signal has only recently emerged from the background noise of natural variability.
323 citations
TL;DR: In this paper, the propagation characteristics of seismic electromagnetic signals (SEMS) both at an ultra low frequency (ULF) and at a very low frequency(VLF) are discussed based on a model experiment of propagation of electromagnetic (EM) waves in the earth's crust and atmospheric waveguide.
55 citations
TL;DR: The vertical structure and power spectrum of the field of internal waves generated in the atmospheric waveguide by random vertical displacements were considered in this paper, where it was shown that the universal "tail" of the spectrum is formed by a strong mode's interaction caused by the advective nonlinearity and that the amplitude of the tail does not depend on the height above the ground.
Abstract: The vertical structure and power spectrum of the field of internal waves generated in the atmospheric waveguide by random vertical displacements were considered in this paper. The two-layered model of the atmosphere being used as a simple model of the waveguide takes into account the discrete spectrum of internal waves (both guided and vertically propagating). It is shown that these waves can produce the thin turbulent layers at certain heights, which are independent of random parameters of the source of internal waves. In the Eulerian frame of variables the wavenumber spectrum of internal waves, both three-dimensional and one-dimensional, tends asymptotically to a universal form at large wavenumbers. It is shown that the universal “tail” of the spectrum is formed by a strong mode's interaction caused by the advective nonlinearity and that the amplitude of the tail does not depend on the height above the ground. The characteristic vertical and horizontal wavenumbers of the three-dimensional Euler...
25 citations
TL;DR: In this article, the mean temperature profile of the atmosphere indicates the probable existence of two horizontally distributed sound waveguides in the atmosphere, the lower one usually occurs between the surface and 50 km, and the upper between 50 and 110 km.
Abstract: The mean temperature profile of the atmosphere indicates the probable existence of two horizontally distributed sound waveguides in the atmosphere. The lower one usually occurs between the surface and 50 km, and the upper between 50 and 110 km. Wind data above 30 km, which have become available recently through the use of meteorological rockets, have resulted in revised concepts of atmospheric circulation patterns for the northern hemisphere. Wind data obtained from these patterns have been combined with mean atmospheric temperature data to determine seasonal sonic patterns of the atmospheric waveguide that can exist between the surface and an altitude of about 50 km. These patterns indicate the general existence of a waveguide for sound having an eastward propagation component in winter and a westward propagation component in summer. For other combinations of propagation directions and seasons, a waveguide does not usually exist between the surface and 50 km. The refraction of sound from upper altitudes to the surface will generally occur only in winter at sites located to the east of the source and in summer at sites located to the west of the source.
20 citations
22 Nov 2017
20 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2020 | 1 |
| 2019 | 4 |
| 2018 | 4 |
| 2017 | 2 |
| 2016 | 1 |
| 2015 | 1 |