Turbulence-induced ionization fluctuations in the lower ionosphere

  • 112 Pages
  • 2.42 MB
  • English

U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration, Environmental Research Laboratories, Environmental Technology Laboratory , Boulder, Colo
Atmospheric ionization -- Mathematical models., Atmospheric turbulence -- Mathematical mo
Other titlesTurbulence induced ionization fluctuations in the lower ionosphere
StatementReginald J. Hill, Kenneth A. Milton.
SeriesNOAA technical report ERL -- 454. -- ETL 68, NOAA technical report ERL -- 454.., NOAA technical report ERL -- 68..
ContributionsMilton, Kenneth A., Environmental Technology Laboratory (Environmental Research Laboratories)
The Physical Object
Paginationiii, 112 p.
ID Numbers
Open LibraryOL17131347M

Hill, R. and K. Mitton, Turbulence-induced ionization fluctuations in the lower ionosphere, NOAA Technical Report ERL November (available from the author or the National Technical Information Service, Port Royal Road, Springfield, VA, USA).Cited by: Turbulence-induced ionization fluctuations in the lower ionosphere Author: Reginald J Hill ; Kenneth A Milton ; Environmental Technology Laboratory (Environmental Research Laboratories).

Low frequency electrostatic fluctuations in the ionosphere are often observed to develop into a strongly turbulent state. Strong turbulence, with a fully developed spectrum seems mostly to be associated with gradient driven instabilities, as discussed for instance in section   The temporal evolution of a turbulent layer is calculated in detail by solving the hydrodynamic equations.

The turbulence is initiated by a Kelvin-Helmholtz instability.

Description Turbulence-induced ionization fluctuations in the lower ionosphere FB2

The field of potential-temperature fluctuations serves as a tracer for modeling entrainment of the mixing ratios of ionized constituents hypothesized to be present in the upper polar by: Turbulence-induced fluctuations in ionization and application to PMSE Article (PDF Available) in Earth Planets and Space 51() July with 44 Reads How we measure 'reads'.

These Acoustic or Gravity waves affect the turbulence of the lower ionosphere, where sporadic Es-layers may appear, too, as well as the turbulence of the F layer.

Subsequently, the produced disturbance starts to propagate in the ionosphere’s wave guide. Results from observations of plasma turbulence induced in the ionosphere and the magnetosphere by an acoustic wave from ground explosions are presented.

Theoretical qualitative models of the. 1 Introduction [2] Very low frequency electromagnetic waves (VLF, 3–30 kHz) may propagate with no significant attenuation over distances of thousands of kilometers through the natural waveguide with boundaries constituted by the ground and the Earth's lower ionosphere.

The electric conductivity of the lower ionosphere as described by the conductivity gradient and the reference height.

Details Turbulence-induced ionization fluctuations in the lower ionosphere FB2

The electrons and ions in Venus' dayside ionosphere are primarily formed by extreme solar UV photoionization of neutral gases in the thermosphere. However, CO 2 +, like N 2 + on Earth, is only a minor ion in the ionosphere.

The major species in Venus' lower ionosphere is O 2 + with a maximum number density of ∼10 6 cm −3. The regular variations that affect the extent Turbulence-induced ionization fluctuations in the lower ionosphere book ionization in the ionosphere can be divided into four main classes: daily, seasonal, year, and day variations.

DAILY. - Daily variations in the ionosphere are a result of the hour rotation of the Earth about its axis. Daily variations of the different layers (fig. ) are summarized as. Galactic CR induce ionization in the stratosphere and troposphere and also in the independent ionosphere layer at altitudes 50–80 km in the D region (Velinov et al., ).

Victor Hess was the first who discovered CR induced ionization in the atmosphere, in   Journal of Atmospheric and Terrestrial Physics, Vol. 51, No. 5, pp.Printed in Great Britain. /89 S+ Maxwell Pergamon Macmillan pic Long-period fluctuations of meteorological origin observed in the lower ionosphere D.

PANCHEVA, E. APOSTOLOV Geophysical Institute, Bulgarian Academy of Science, 'Academy G. Bonchev' 3, Sofia, Bulgaria and J. Geophysics. The ionosphere is a shell of electrons and electrically charged atoms and molecules that surrounds the Earth, stretching from a height of about Template:Convert to more than Template: owes its existence primarily to ultraviolet radiation from the Sun.

The lowest part of the Earth's atmosphere, the troposphere extends from the surface to about Template:Convert. Hence, the image horizontal resolution should be ~ m or smaller and the integration period should be ~20 s or shorter. Finally, the image photon noise must be small enough to observe the small turbulence‐induced fluctuations, which determines the required sensitivity of the imager given the natural brightness of the OH* emissions.

Turbulence-induced ionization fluctuations in the lower ionosphere. As part of a larger research project to calculate radar scattering from the lower ionosphere using numerical simulation of internal wave breaking and shear instabilities, sub grid-scale turbulence advection modeling is required to calculate the radar-scattering cross.

Purchase The Ionosphere - 1st Edition. Print Book & E-Book. ISBNPartnered Journals. Chinese Journal of Geophysics () Earth Interactions; Earth and Planetary Physics; Geophysics; International Journal of Geomagnetism and Aeronomy.

In the spectrogram, the impulsive features near 5 UT and 8 UT are “early VLF” perturbations caused by transient ionization in the D region ionosphere created by the lightning quasi‐electrostatic field and/or electromagnetic pulse [e.g., Inan et al., ; Marshall et al., ].

Nonthermal scattering produced by the ionization fluctuations induced by turbulence has been used in VHF ionospheric forward scatter communication (BAILEY et al., ; WIESNEB, ) for more than two decades, but has received scant attention as a.

Sound Vib. (i ) 6 (a), i zo8 AN AERODYNAMIC-ACOUSTIC THEORY OF HIGH-ALTITUDE FLUCTUATION PHENOMENAfi R. IYENGAR Mount Allison University, Sackville, New Brunswick, Canada (Received 24 November ) A dynamical coupling exists between the troposphere and the lower ionosphere via the acoustic waves generated in the turbulence of the tropospheric regions.

A three‐dimensional model of the scattering of VLF waves in the Earth‐ionosphere waveguide by localized disturbances in the lower ionosphere is examined for. This is due to the sudden disappearance of ionization in the lower ionosphere after sunset (fast recombination processes and loss of photoionization).

As a result strong eastward electric fields are induced in the E‐region, and a sharp enhancement of upward ion velocity occurs, the so‐called prereversal enhancement [ Heelis et al., ]. Hill R J and Bowhill S A Collision frequencies for use in the continuum momentum equations applied to the lower ionosphere J.

Atmos. Terr. Phys. 39 –11 Crossref Hill R J and Mitton K A Turbulence-induced ionization fluctuations in the lower ionosphere NOAA Technical Report ERL ETL The ionosphere contains charged particles due to intense UV radiations from the the day there may be four regions present called the D, E, F1 (lower) and F2 (upper) regions.

The solution of the MHD equations of slightly ionized plasma, modeling explosive action on radio-frequency discharge under the conditions of the lower ionosphere, has been presented. ionization and increased absorption of electromagnetic waves in the sunlit hemisphere in the D- and E-regions of the Earth’s ionosphere.

In addition, solar flares are also accompanied by energetic particles (protons and electrons) with energies from tens of keV to hundreds of MeV and attendant ionization.

Geophysical Research Letters; Global Biogeochemical Cycles; Journal of Advances in Modeling Earth Systems (JAMES). We present the results of studying the sporadic layers of ionization in the lower ionosphere observed in the sunset-sunrise time during the summer months of and @article{osti_, title = {The use of subionospheric VLF/LF propagation for the study of lower ionospheric perturbations associated with earthquakes}, author = {Hayakawa, M}, abstractNote = {It is recently recognized that the ionosphere is very sensitive to seismic effects, and the detection of ionospheric perturbations associated with earthquakes (EQs), attracts a lot of attention as a.

Occurrence rate of ionosphere disturbance at Kokubunji. Top panel shows the number of the earthquakes of different magnitudes (black bar for EQs of ≤ M in the lower three panes indicate the event percentage of positive and negative anomaly, respectively.

Within approximately ± 20 degrees of the magnetic equator, is the equatorial is the occurrence of a trough of concentrated ionization in the F 2 layer. The Earth's magnetic field lines are horizontal at the magnetic equator.

Solar heating and tidal oscillations in the lower ionosphere move plasma up and across the magnetic field lines.

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Comparison of the EISCAT-derived quasi-TEC fluctuations \(\left\langle {N_{\text{e}} } \right\rangle\) with periodic vTEC variations shows that a closest match is observed for the bottom ionosphere, evidencing that the main contribution is provided by the lower ionosphere, up to ~ km (that is the E-layer and lower F-layer).Es on lower frequencies could mean more scattering (due to ionospheric turbulence = changes in ionization) on higher frequencies.

The Es cloud should be at about mid of the MHz path. Polar Mesosphere Summer Echoes, PMSE is a kind of summertime polar Es at km. PSME gives increased radar echoes on certain days most often in June and.