1
|
Magnetic Field and Electron Density Scaling Properties in the Equatorial Plasma Bubbles. REMOTE SENSING 2022. [DOI: 10.3390/rs14040918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
The ionospheric plasma density irregularities are known to play a role in the propagation of electromagnetic signals and to be one of the most important sources of disturbance for the Global Navigation Satellite System, being responsible for degradation and, sometimes, interruptions of the signals received by the system. In the equatorial ionospheric F region, these plasma density irregularities, known as plasma bubbles, find the suitable conditions for their development during post-sunset hours. In recent years, important features of plasma bubbles such as their dependence on latitude, longitude, and solar and geomagnetic activities have been inferred indirectly using their magnetic signatures. Here, we study the scaling properties of both the electron density and the magnetic field inside the plasma bubbles using measurements on board the Swarm A satellite from 1 April 2014 to 31 January 2016. We show that the spectral features of plasma irregularities cannot be directly inferred from their magnetic signatures. A relation more complex than the linear one is necessary to properly describe the role played by the evolution of plasma bubbles with local time and by the development of turbulent phenomena.
Collapse
|
2
|
Ionospheric Turbulence and the Equatorial Plasma Density Irregularities: Scaling Features and RODI. REMOTE SENSING 2021. [DOI: 10.3390/rs13040759] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
In the framework of space weather, the understanding of the physical mechanisms responsible for the generation of ionospheric irregularities is particularly relevant for their effects on global positioning and communication systems. Ionospheric equatorial plasma bubbles are one of the possible irregularities. In this work, using data from the ESA Swarm mission, we investigate the scaling features of electron density fluctuations characterizing equatorial plasma bubbles. Results strongly support a turbulence character of these structures and suggest the existence of a clear link between the observed scaling properties and the value of the Rate Of change of electron Density Index (RODI). This link is discussed, and RODI is proposed as a reliable proxy for the identification of plasma bubbles.
Collapse
|
3
|
Kil H, Lee WK, Paxton LJ. Origin and Distribution of Daytime Electron Density Irregularities in the Low-Latitude F Region. JOURNAL OF GEOPHYSICAL RESEARCH. SPACE PHYSICS 2020; 125:e2020JA028343. [PMID: 32999808 PMCID: PMC7507783 DOI: 10.1029/2020ja028343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 07/22/2020] [Accepted: 07/31/2020] [Indexed: 06/11/2023]
Abstract
Electron density irregularities on the dayside in the low-latitude F region are understood as remnants (or fossils) of nighttime plasma bubbles. We provide observational evidence of the connection of daytime irregularities to nighttime bubbles and the transport of the daytime irregularities by the vertical motion of the background ionosphere. The distributions of irregularities are derived using the measurements of the ion density by the first Republic of China satellite from March 1999 to June 2004. The seasonal and longitudinal distributions of daytime and nighttime irregularities in low latitudes show a close similarity. The high occurrence rate of daytime irregularities at the longitudes where strong irregularities occur frequently at night provides strong evidence of the association of daytime irregularities with nighttime bubbles. Nighttime irregularities are concentrated in the equatorial region, whereas daytime irregularities spread over broader latitudes. The seasonal and longitudinal variation of the latitudinal spread of daytime irregularities is consistent with the morphologies of plasma density and vertical plasma velocity. The zonal wave number 4 pattern, which corresponds to that in plasma density, is identified in the distribution of daytime irregularities. These observations lead to the conclusion that the morphology of daytime irregularities in the low-latitude F region is dominated by the morphology of bubbles at night and the ionospheric fountain process on the dayside.
Collapse
Affiliation(s)
- Hyosub Kil
- The Johns Hopkins University Applied Physics LaboratoryLaurelMDUSA
| | | | - Larry J. Paxton
- The Johns Hopkins University Applied Physics LaboratoryLaurelMDUSA
| |
Collapse
|
4
|
Davidson RL, Oborn B, Robertson EF, Noel S, Earle GD, Green J, Kramer J. The gridded retarding ion drift sensor for the petitSat cubeSat mission. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:064502. [PMID: 32611012 DOI: 10.1063/1.5140470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 05/20/2020] [Indexed: 06/11/2023]
Abstract
The Gridded Retarding Ion Drift Sensor (GRIDS) is a small sensor that will fly on the 6 U petitSat CubeSat. It is designed to measure the three-dimensional plasma drift velocity vector in the Earth's ionosphere. The GRIDS also supplies information about the ion temperature, ion density, and the ratio of light to heavy ions present in the ionospheric plasma. It utilizes well-proven techniques that have been successfully validated by similar instruments on larger satellite missions while meeting CubeSat-compatible requirements for low mass, size, and power consumption. GRIDS performs the functions of a Retarding Potential Analyzer (RPA) and an Ion Drift Meter (IDM) by combining the features of both types of instruments in a single package. The sensor alternates RPA and IDM measurements to produce the full set of measurement parameters listed above. On the petitSat mission, GRIDS will help identify and characterize a phenomenon known as plasma blobs (or enhancements).
Collapse
Affiliation(s)
- R L Davidson
- Electrical and Computer Engineering, Utah State University, Logan, Utah 84322, USA
| | - B Oborn
- Electrical and Computer Engineering, Utah State University, Logan, Utah 84322, USA
| | - E F Robertson
- Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061, USA
| | - S Noel
- Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061, USA
| | - G D Earle
- Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061, USA
| | - J Green
- Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061, USA
| | - J Kramer
- Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061, USA
| |
Collapse
|
5
|
Investigation of the Occurrence of Nighttime Topside Ionospheric Irregularities in Low-Latitude and Equatorial Regions Using CYGNSS Satellites. SENSORS 2020; 20:s20030708. [PMID: 32012876 PMCID: PMC7038482 DOI: 10.3390/s20030708] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 01/20/2020] [Accepted: 01/25/2020] [Indexed: 11/17/2022]
Abstract
By using multi-satellite observations of the L1 signal-to-noise ratio (SNR) from the Cyclone Global Navigation Satellite System (CYGNSS) taken in 2017, we present the occurrence of nighttime topside ionospheric irregularities in low-latitude and equatorial regions. The most significant finding of this study is the existence of longitudinal structures with a wavenumber 4 pattern in the topside irregularities. This suggests that lower atmospheric waves, especially a daytime diurnal eastward-propagating zonal wave number-3 nonmigrating tide (DE3), might play an important role in the generation of topside plasma bubbles during the low solar minimum. Observations of scintillation events indicate that the maximum occurrence of nighttime topside ionospheric irregularities occurs on the magnetic equator during the equinoxes. The current work, which could be regarded as an important update of the previous investigations, would be readily for the further global analysis of the topside ionospheric irregularities.
Collapse
|
6
|
McDaniel A, Mahalov A. Stochastic mirage phenomenon in a random medium. OPTICS LETTERS 2017; 42:2002-2005. [PMID: 28504734 DOI: 10.1364/ol.42.002002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In the framework of geometric optics, we consider the problem of characterizing the ray trajectory in a random medium with a mean refractive index gradient. Such a gradient results in the mirage phenomenon where an object's observed location is displaced from its actual location. We derive formulas for the mean ray path in both the situation of isotropic stochastic fluctuations and an important anisotropic case. For the isotropic model, the mean squared displacement is also given by a simple formula. Our results could be useful for applications involving the propagation of electromagnetic waves through the atmosphere, where larger-scale mean gradients and smaller-scale stochastic fluctuations are both present.
Collapse
|
7
|
Fanelli L, Noel S, Earle GD, Fish C, Davidson RL, Robertson RV, Marquis P, Garg V, Somasundaram N, Kordella L, Kennedy P. A versatile retarding potential analyzer for nano-satellite platforms. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2015; 86:124501. [PMID: 26724049 DOI: 10.1063/1.4937622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The design of the first retarding potential analyzer (RPA) built specifically for use on resource-limited cubesat platforms is described. The size, mass, and power consumption are consistent with the limitations of a nano-satellite, but the performance specifications are commensurate with those of RPAs flown on much larger platforms. The instrument is capable of measuring the ion density, temperature, and the ram component of the ion velocity in the spacecraft reference frame, while also providing estimates of the ion composition. The mechanical and electrical designs are described, as are the operating modes, command and data structure, and timing scheme. Test data obtained using an ion source inside a laboratory vacuum chamber are presented to validate the performance of the new design.
Collapse
Affiliation(s)
- L Fanelli
- Virginia Tech, Blacksburg, Virginia 24061, USA
| | - S Noel
- Virginia Tech, Blacksburg, Virginia 24061, USA
| | - G D Earle
- Virginia Tech, Blacksburg, Virginia 24061, USA
| | - C Fish
- Virginia Tech, Blacksburg, Virginia 24061, USA
| | | | | | - P Marquis
- Virginia Tech, Blacksburg, Virginia 24061, USA
| | - V Garg
- Virginia Tech, Blacksburg, Virginia 24061, USA
| | | | - L Kordella
- Virginia Tech, Blacksburg, Virginia 24061, USA
| | - P Kennedy
- Virginia Tech, Blacksburg, Virginia 24061, USA
| |
Collapse
|
8
|
Aveiro HC, Hysell DL. Three-dimensional numerical simulation of equatorialFregion plasma irregularities with bottomside shear flow. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2010ja015602] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- H. C. Aveiro
- Department of Earth and Atmospheric Sciences; Cornell University; Ithaca New York USA
| | - D. L. Hysell
- Department of Earth and Atmospheric Sciences; Cornell University; Ithaca New York USA
| |
Collapse
|
9
|
Huang CY, Burke WJ, Machuzak JS, Gentile LC, Sultan PJ. DMSP observations of equatorial plasma bubbles in the topside ionosphere near solar maximum. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2000ja000319] [Citation(s) in RCA: 139] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
10
|
Whalen JA. An equatorial bubble: Its evolution observed in relation to bottomside spreadFand to the Appleton anomaly. ACTA ACUST UNITED AC 2000. [DOI: 10.1029/1999ja900441] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
11
|
McClure JP, Singh S, Bamgboye DK, Johnson FS, Kil H. Occurrence of equatorial F region irregularities: Evidence for tropospheric seeding. ACTA ACUST UNITED AC 1998. [DOI: 10.1029/98ja02749] [Citation(s) in RCA: 146] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
12
|
MacDougall JW, Abdu MA, Jayachandran PT, Cecile JF, Batista IS. Presunrise spread F
at Fortaleza. ACTA ACUST UNITED AC 1998. [DOI: 10.1029/98ja01949] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|