scholarly journals Estimated influence of stratospheric activity on the ionosphere according to measurements with ISTP SB RAS tools

2021 ◽  
Vol 7 (4) ◽  
pp. 79-84
Author(s):  
Maksim Tolstikov ◽  
Konstantin Ratovsky ◽  
Irina Medvedeva ◽  
Denis Khabituev
Keyword(s):  
Gravity Waves ◽  
Lower Thermosphere ◽  
Correlation Coefficients ◽  
Internal Gravity Waves ◽  
Reanalysis Data ◽  
Time Shift ◽  
Ionospheric Disturbances ◽  
Time Intervals ◽  
Temperature Variations ◽  
Comprehensive Study

We present the results of a comprehensive study of the manifestation of wave activity with periods of internal gravity waves (IGW) in various regions of the atmosphere: in the stratosphere, upper mesosphere, and in the F2-region of the ionosphere. The study is based on radiophysical and spectrometric measurements made with tools of the Institute of Solar-Terrestrial Physics (ISTP) SB RAS and the Era-Interim reanalysis data. The correlation coefficient with time shift between ionospheric and stratospheric activity for the annual interval varies in the range from 0.45 to 0.54, and for the 27-day interval it reaches the levels 0.4–0.8 in seventy percent of the cases. Thirty percent of correlation coefficients less than 0.4 can be explained by the influence of neutral wind, geomagnetic activity, and non-stratospheric IGW sources. Comparison between stratospheric activity and variations in characteristics of traveling ionospheric disturbances (TID) has shown that a ~15 day shift in stratospheric activity results in a fairly high correlation between stratospheric activity and disturbance of IGW characteristics (~0.6). The delay of about 15 days can be attributed to the delay in the temperature variations at heights of the lower thermosphere relative to the temperature variations at the altitude pressure level of 1 hPa. Comparative analysis of variations in mesospheric and ionospheric activity has revealed time intervals when their behavior is consistent.

scholarly journals Estimated influence of stratospheric activity on the ionosphere according to measurements with ISTP SB RAS tools

2021 ◽  
Vol 7 (4) ◽  
pp. 84-90
Author(s):  
Maksim Tolstikov ◽  
Konstantin Ratovsky ◽  
Irina Medvedeva ◽  
Denis Khabituev
Keyword(s):  
Gravity Waves ◽  
Lower Thermosphere ◽  
Correlation Coefficients ◽  
Internal Gravity Waves ◽  
Reanalysis Data ◽  
Time Shift ◽  
Ionospheric Disturbances ◽  
Time Intervals ◽  
Temperature Variations ◽  
Comprehensive Study

We present the results of a comprehensive study of the manifestation of wave activity with periods of internal gravity waves (IGW) in various regions of the atmosphere: in the stratosphere, upper mesosphere, and in the F2-region of the ionosphere. The study is based on radiophysical and spectrometric measurements made with tools of the Institute of Solar-Terrestrial Physics (ISTP) SB RAS and the Era-Interim reanalysis data. The correlation coefficient with time shift between ionospheric and stratospheric activity for the annual interval varies in the range from 0.45 to 0.54, and for the 27-day interval it reaches the levels 0.4–0.8 in seventy percent of the cases. Thirty percent of correlation coefficients less than 0.4 can be explained by the influence of neutral wind, geomagnetic activity, and non-stratospheric IGW sources. Comparison between stratospheric activity and variations in characteristics of traveling ionospheric disturbances (TID) has shown that a ~15 day shift in stratospheric activity results in a fairly high correlation between stratospheric activity and disturbance of IGW characteristics (~0.6). The delay of about 15 days can be attributed to the delay in the temperature variations at heights of the lower thermosphere relative to the temperature variations at the altitude pressure level of 1 hPa. Comparative analysis of variations in mesospheric and ionospheric activity has revealed time intervals when their behavior is consistent.

scholarly journals The Influence of Tropospheric Processes on Disturbances in the D and E Ionospheric Layers

Atmosphere ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1116
Author(s):  
Olga P. Borchevkina ◽  
Sergey O. Adamson ◽  
Yurii A. Dyakov ◽  
Ivan V. Karpov ◽  
Gennady V. Golubkov ◽  
...  
Keyword(s):  
Gravity Waves ◽  
Spatial Scales ◽  
Internal Gravity Waves ◽  
Ionospheric Disturbances ◽  
Satellite Measurements ◽  
Atmospheric Physics ◽  
Temperature Variations ◽  
Physical Mechanisms ◽  
Lidar Observations

Determination of the physical mechanisms of the energy transfer of tropospheric disturbances to the ionosphere is one of the fundamental problems of atmospheric physics. This article presents the observational results of tropospheric and ionospheric disturbances during the passages of the solar terminator and solar eclipse. Lidar observations showed the occurrence of tropospheric regions with noticeably increased amplitudes of density, pressure, and temperature variations with periods corresponding to acoustic and internal gravity waves, which were generated in the troposphere during the development of these events. Simultaneous satellite measurements demonstrate the response of the ionosphere to these tropospheric disturbances. Based on the experimental data, we determine the typical periods and spatial scales of variations. It is shown that the response time of the ionosphere to tropospheric disturbances is 30–40 min.

Effects of Nonlinearity on Convectively Forced Internal Gravity Waves: Application to a Gravity Wave Drag Parameterization

2008 ◽  
Vol 65 (2) ◽  
pp. 557-575 ◽  
Author(s):  
Hye-Yeong Chun ◽  
Hyun-Joo Choi ◽  
In-Sun Song
Keyword(s):  
Gravity Wave ◽  
Gravity Waves ◽  
Momentum Flux ◽  
Lower Thermosphere ◽  
Internal Gravity Waves ◽  
Wave Drag ◽  
Scale Factor ◽  
Wide Range ◽  
Flux Spectrum ◽  
Diabatic Forcing

Abstract In the present study, the authors propose a way to include a nonlinear forcing effect on the momentum flux spectrum of convectively forced internal gravity waves using a nondimensional numerical model (NDM) in a two-dimensional framework. In NDM, the nonlinear forcing is represented by nonlinear advection terms multiplied by the nonlinearity factor (NF) of the thermally induced internal gravity waves for a given specified diabatic forcing. It was found that the magnitudes of the waves and resultant momentum flux above the specified forcing decrease with increasing NF due to cancellation between the two forcing mechanisms. Using the momentum flux spectrum obtained by the NDM simulations with various NFs, a scale factor for the momentum flux, normalized by the momentum flux induced by diabatic forcing alone, is formulated as a function of NF. Inclusion of the nonlinear forcing effect into current convective gravity wave drag (GWD) parameterizations, which consider diabatic forcing alone by multiplying the cloud-top momentum flux spectrum by the scale factor, is proposed. An updated convective GWD parameterization using the scale factor is implemented into the NCAR Whole Atmosphere Community Climate Model (WACCM). The 10-yr simulation results, compared with those by the original convective GWD parameterization considering diabatic forcing alone, showed that the magnitude of the zonal-mean cloud-top momentum flux is reduced for wide range of phase speed spectrum by about 10%, except in the middle latitude storm-track regions where the cloud-top momentum flux is amplified. The zonal drag forcing is determined largely by the wave propagation condition under the reduced magnitude of the cloud-top momentum flux, and its magnitude decreases in many regions, but there are several areas of increasing drag forcing, especially in the tropical upper mesosphere and lower thermosphere.

Internal Gravity Waves in the Lower Thermosphere with Linear Temperature Profile: Theory and Experiment

2017 ◽  
Vol 60 (2) ◽  
pp. 103-112 ◽  
Author(s):  
N. V. Bakhmet’eva ◽  
G. I. Grigor’ev ◽  
A. V. Tolmacheva ◽  
E. E. Kalinina ◽  
M. N. Egerev
Keyword(s):  
Temperature Profile ◽  
Gravity Waves ◽  
Lower Thermosphere ◽  
Internal Gravity Waves ◽  
Linear Temperature ◽  
Theory And Experiment

scholarly journals Parameters of internal gravity waves in the mesosphere-lower thermosphere region derived from meteor radar wind measurements

2005 ◽  
Vol 23 (11) ◽  
pp. 3431-3437 ◽  
Author(s):  
A. N. Oleynikov ◽  
Ch. Jacobi ◽  
D. M. Sosnovchik
Keyword(s):  
Gravity Waves ◽  
High Frequency ◽  
Lower Thermosphere ◽  
Radar Data ◽  
Internal Gravity Waves ◽  
Meteor Radar ◽  
Energy Propagation ◽  
Data Set ◽  
Wind Measurements ◽  
Phase Progression

Abstract. A procedure of revealing parameters of internal gravity waves from meteor radar wind measurements is presented. The method is based on dividing the measuring volume into different parts and, using wavelet analysis, calculating the phase progression of frequency peaks in the vertical and horizontal direction. Thus, the distribution of vertical and horizontal wavelengths and directions of IGW energy propagation, using meteor radar data, has been obtained. The method was applied to a 4-month data set obtained in July and August, 1998 and 1999. As expected, the majority of waves have been found to propagate upwards, although a considerable number seem to propagate downwards as well. High-frequency (intrinsic periods T* of less than 2 h) waves are dominating. The distribution of waves over the course of an average day is only weakly structured, with weak maxima in the morning and evening.

scholarly journals The ionosphere and radio interferometry

1997 ◽  
Vol 40 (4) ◽  
Author(s):  
T. A. Th. Spoelstra
Keyword(s):  
Gravity Waves ◽  
Daily Variation ◽  
Lower Thermosphere ◽  
Time Of Day ◽  
Ionospheric Disturbances ◽  
Frequency Of Occurrence ◽  
Radio Interferometry ◽  
Travelling Ionospheric Disturbances ◽  
Propagation Parameters ◽  
Definition Of

This paper reviews the effects of the ionosphere on radio astronomjcal observations, what we can learn about the ionosphere from radio interferometry, and a procedure to correct for these effects. This study analyzes the results obtained from observations of celestial point soUl.ces with the Westerbork Synthesis Radio Telescope, WSRT, in the Netherlands from the period 1970-1991. The main conc1usions are: 1) A1though seasona1 effects are c1ear, the occurrence and "strength" of ionospheric irregu1arities show no dependence on solar activity. 2) Assuming that the frequency of occurrence of ionospheric disturbances in Spring and Autumn are similar, Ihe "ionospheric" Winter starts on day 348 ± 3 and ali seasons last for three months. 3) Travelling ionospheric disturbances, TIDs, occur most frequently during daytime in Winter periods. 4) The propagation parameters of these travelling ionospheric irregularities and their periods indicate that these belong main1y to the c1ass of medium sca]e TIDs. 5) Radio interferometry is a powerful tool to locate irregularities causing scintillation and to determine their dimensions. 6) The occurrence of non-periodic irregu1arities is, however, not a function of time of day. 7) The daily variation in the amplitude and frequency of occurrence of the TIDs suggest that the generation of gravity waves may be caused by winds and tides in the lower thermosphere/mesosphere. On the basis of the availab1e data, a definition of a "disturbance measure" indicating to what extent the ionosphere is "quiet" is proposed. Procedures to correct for ionospheric effects and an eva1uation of the different methods to obtain information on the ionospheric e1ectron content are reviewed in sections 8 and 9, respectively.

scholarly journals First GPS TEC maps of ionospheric disturbances induced by reflected tsunami waves: The Tohoku case study

2016 ◽  
Author(s):  
L. Tang ◽  
Y. Zhao ◽  
J. An
Keyword(s):  
Gravity Waves ◽  
Arrival Time ◽  
Tohoku Earthquake ◽  
Internal Gravity Waves ◽  
Ionospheric Disturbances ◽  
Propagation Characteristics ◽  
Tsunami Waves ◽  
Travelling Ionospheric Disturbances ◽  
Ionospheric Height

Abstract. The straight tsunami waves from epicenter can be reflected when they reach to coasts or underwater obstacles. In this study, we present the first ionospheric maps of reflected tsunami signature caused by the great 11 March 2011 Tohoku earthquake using the dense GPS network GEONET in Japan. We observed tsunami-like travelling ionospheric disturbances (TIDs) with similar propagation characteristics in terms of waveform, horizontal velocity, direction, period and arrival time compared to the reflected tsunami at the sea-level, indicating the TIDs are induced by the reflected tsunami. The results confirm the atmospheric internal gravity waves (IGWs) produced by reflected tsunami can also propagate upward to the atmosphere and interact with the plasma at the ionospheric height.

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