scholarly journals Plasma irregularities in the duskside subauroral ionosphere as observed with midlatitude SuperDARN radar in Hokkaido, Japan

Radio Science ◽  
2010 ◽  
Vol 45 (4) ◽  
pp. n/a-n/a ◽  
Author(s):  
K. Hosokawa ◽  
N. Nishitani
Keyword(s):  
Plasma Irregularities

Statistics of pulsating auroras on the basis of all-sky TV data from five stations. I. Occurrence frequency

1981 ◽  
Vol 59 (8) ◽  
pp. 1150-1157 ◽  
Author(s):  
T. Oguti ◽  
S. Kokubun ◽  
K. Hayashi ◽  
K. Tsuruda ◽  
S. Machida ◽  
...  
Keyword(s):  
Local Time ◽  
Cold Plasma ◽  
Geomagnetic Latitude ◽  
Auroral Oval ◽  
Magnetic Activity ◽  
Occurrence Frequency ◽  
Frequency Of Occurrence ◽  
Occurrence Probability ◽  
Energetic Electrons ◽  
Plasma Irregularities

The frequency of occurrence of pulsating auroras is statistically examined on the basis of all-sky TV data for 34 nights from five stations, in a range from 61.5 to 74.3° in geomagnetic latitude. The results are that: (1) occurrence probability of a pulsating aurora is 100% after 4 h in geomagnetic local time, (2) pulsating auroras occur in the morning hours along the auroral oval even when magnetic activity is as small as 0o ≤ Kp ≤ 1, (3) pulsating auroras occur even in the evening when Kp increases to greater than 3−, (4) drift of pulsating auroras is westward in the evening while it is eastward in the morning hours, (5) the region of pulsating auroras splits into two zones, 64 to 68° and 61 to 63° in geomagnetic latitude, after 4 h geomagnetic local time for Kp from 2o to 3−, and the splitting also appears to exist for greater Kp as evidenced by observation other than our auroral data. These results are discussed in relation to distributions of cold plasma irregularities and energetic electrons in the magnetosphere.

scholarly journals 3-D Radar Imaging of E-Region Field-Aligned Plasma Irregularities by Using Multireceiver and Multifrequency Techniques

2018 ◽  
Vol 56 (10) ◽  
pp. 5591-5599 ◽  
Author(s):  
Jenn-Shyong Chen ◽  
Chien-Ya Wang ◽  
Yen-Hsyang Chu ◽  
Ching-Lun Su ◽  
Hiroyuki Hashiguchi
Keyword(s):  
Radar Imaging ◽  
Plasma Irregularities ◽  
E Region

scholarly journals Plasma irregularities in the tropical F-region detected by OI 7774 Å and 6300 Å nightglow measurements

1981 ◽  
Vol 86 (A5) ◽  
pp. 3496 ◽  
Author(s):  
Y. Sahai ◽  
J. A. Bittencourt ◽  
N. R. Teixeira ◽  
H. Takahashi
Keyword(s):  
Plasma Irregularities ◽  
F Region

scholarly journals Characterization of ionospheric irregularities over Vietnam and adjacent region for the 2008-2018 period

2021 ◽  
Author(s):  
Dung Nguyen Thanh ◽  
Minh Le Huy ◽  
Christine Amory-Mazaudier ◽  
Rolland Fleury ◽  
Susumu Saito ◽  
...  
Keyword(s):  
Solar Activity ◽  
Correlation Coefficients ◽  
Rate Of Change ◽  
Occurrence Rate ◽  
High Solar Activity ◽  
Electron Content ◽  
Total Electron ◽  
Plasma Irregularities ◽  
Almost All ◽  
Continuous Gps

This paper presents the variations of the rate of change of Total Electron Content (TEC) index (ROTI), characterizing the occurrence of ionospheric plasma irregularities over Vietnam and neighboring countries in the Southeast Asian region using the continuous GPS data during the 2008-2018 period. The results showed that the occurrence of strong ROTI in all stations is maximum in equinox months March/April and September/October and depends on solar activity. The ROTI is weak during periods of low solar activity and strong during periods of high solar activity. There is an asymmetry between the two equinoxes. During maximum and declining phases of 2014-2016, occurrence rates in March equinox are larger than in September equinox, but during the descending period of 2010-2011, the occurrence rates in September equinox at almost all stations are larger than in March equinox. The correlation coefficients between the monthly occurrence rate of irregularities and the F10.7 solar index at the stations in the equatorward EIA crest region are higher than at those in the magnetic equatorial and the poleward EIA crest regions. The irregularity occurrence is high in the pre-midnight sector, maximum between 2000 LT to 2200 LT. The maximum irregularity occurrence is located around 4-5° degrees in latitude equator-ward away from the anomaly crests.

scholarly journals Plasma irregularities adjacent to auroral patches in the postmidnight sector

2010 ◽  
Vol 115 (A9) ◽  
pp. n/a-n/a ◽  
Author(s):  
K. Hosokawa ◽  
T. Motoba ◽  
A. S. Yukimatu ◽  
S. E. Milan ◽  
M. Lester ◽  
...  
Keyword(s):  
Plasma Irregularities

Quasi real-time monitoring of the ionosphere plasma irregularities by the records of the Swarm mission

2021 ◽  
Author(s):  
Peter Kovacs ◽  
Balazs Heilig
Keyword(s):  
Magnetic Field ◽  
Temporal Distribution ◽  
Typical Feature ◽  
Low Earth Orbit ◽  
Space Environment ◽  
Signal Loss ◽  
Plasma Bubble ◽  
Plasma Irregularities ◽  
Ionosphere Plasma ◽  
Swarm Mission

<p>The magnetic and plasma observations of Low-Earth orbit (LEO) space missions represent not only the dynamical state of the ionosphere but also the physical variations of its electromagnetically connected surroundings, i.e. of the plasmasphere and magnetosphere, as well as of their driver, the solar wind. The monitoring of the ionosphere plasma variables is therefore a big asset for the study of our space environment in broad spatial region. Within the framework of the EPHEMERIS project supported by ESA, we aim at investigating two ionosphere phenomena that exhibit close relationship to global physical processes and space weather activity. We use the magnetic and plasma records of the LEO Swarm mission. First, we investigate the temporal and spatial occurrences of the mid-latitude ionosphere trough (MIT), a typical feature of the topside sub-auroral ionosphere appearing as a few degree wide depleted zone, where electron density (Ne) drops by orders of magnitude. It is shown that the locations of MITs are excellent proxies for the detection of the plasmapause position as well as of the equatorward edge of the auroral oval. Secondly, we monitor the irregular fluctuations of the magnetic field along the Swarm orbits via their intermittent behaviour. A new index called intermittency index (IMI) is introduced for the quantitative exemplification of the spatial and temporal distribution of irregular variations at the Swarm spacecraft altitudes. The paper focuses on the introduction of the methodology of IMI time-series compilation. Since IMIs are deduced via a statistical approach, we use the 50 Hz sampling frequency magnetic field records of the mission. We show that most frequently, the ionosphere magnetic field irregularities occur at low-latitudes, about the dip equator and at high latitudes, around the auroral region. It is conjectured that the equatorial events are the results of equatorial spread F (ESF) or equatorial plasma bubble (EPB) phenomena, while the auroral irregularities are related to field-aligned currents (FAC). The ionosphere plasma irregularities may result in the distortion or loss of GPS signals. Therefore our analysis also concerns the investigation of the correlation between observed intermittent events in the ionosphere and contemporary GPS signal loss events and scintillations detected both by on-board Swarm GPS receivers and ground GNSS stations.</p>

Modeling and analysis of LOFAR scintillation data

2021 ◽  
Author(s):  
Marcin Grzesiak ◽  
Mariusz Pożoga ◽  
Barbara Matyjasiak ◽  
Dorota Przepiórka ◽  
Hanna Rothkaehl ◽  
...  
Keyword(s):  
Full Range ◽  
Cosmic Radio ◽  
Radio Emissions ◽  
Modeling And Analysis ◽  
Plasma Irregularities ◽  
Time Space ◽  
Cosmic Medium ◽  
Evolution Characteristics ◽  
Space Frequency ◽  
Good Coverage

<p>Scintillation of beacon satellite signals or distant cosmic radio emissions can provide interesting information on the cosmic medium itself, its internal spatial structure and basic evolution characteristics. LOFAR network gives consistent scintillation data with good coverage both in time and space and for the frequency range that goes down close to the local plasma frequency (LBA) being thus sensible to ionospheric plasma irregularities. LOFAR Scintillation measurements in the LBA range exhibit very interesting morphologies. Based on scintillation simulations using the phase screen method, including multiple scattering and refraction, we try to untangle the information contained in the full range (time, space, frequency) of LOFAR data and verify a number of hypotheses about the local structure of the ionosphere and its evolution.</p>

Research Progresses of Ionospheric Plasma Irregularities from the Ground–Based Airglow Network in China

2021 ◽  
Author(s):  
Jiyao Xu ◽  
Wei Yuan ◽  
Kun Wu ◽  
Longchang Sun
Keyword(s):  
Ionospheric Plasma ◽  
Ionospheric Disturbance ◽  
Geomagnetic Latitude ◽  
Extreme Weather Events ◽  
Plasma Bubble ◽  
Low Latitude ◽  
Plasma Irregularities ◽  
Middle Latitudes ◽  
Weather Events ◽  
New Phenomena

<p>China, from north to south, spans from the middle latitudes to the low latitude both in geographic latitude and geomagnetic latitude. And China has a variety of topography environment, which including high lands, plains, seas, and long coasts. To better understand topographic and latitudinal effects on the mesosphere and thermosphere and features of ionospheric plasma irregularities at various latitudes in China, we have established a ground-based airglow network in China gradually since 2010, which consists of 16 stations. This network almost cover China, which focuses on two airglow layers: the OI (~250 km) and OH (~87 km) airglow layers. The observations from OI airglow layers provide convenience to systematically investigate the morphologic feature and evolution of ionospheric plasma irregularities over China. Based on the airglow network observations, we mainly report some important research results of ionospheric plasma irregularities in recent years. These findings include (1) statistical characteristic of equatorial plasma bubble (EPB) over China, (2) the influences of severe extreme weather events on the ionosphere, (3) interaction between medium-scale traveling ionospheric disturbance (MSTIDs) and ionospheric irregularity, and (4) some new phenomena of ionospheric irregularities.</p>

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