Empirical model of the E-region electron temperature around noon and at low magnetic activity

1985 ◽  
Vol 33 (8) ◽  
pp. 909-914 ◽  
Author(s):  
S. Duhau ◽  
M.C. Azpiazu
Keyword(s):  
Electron Temperature ◽  
Empirical Model ◽  
Magnetic Activity ◽  
E Region

scholarly journals An empirical model (CH-Therm-2018) of the thermospheric mass density derived from CHAMP

2018 ◽  
Author(s):  
Chao Xiong ◽  
Hermann Lühr ◽  
Michael Schmidt ◽  
Mathis Bloßfeld ◽  
Sergei Rudenko
Keyword(s):  
Empirical Model ◽  
Solar Minimum ◽  
Mass Density ◽  
Precise Orbit Determination ◽  
Wave Pattern ◽  
Magnetic Activity ◽  
Low Earth Orbit ◽  
Naval Research ◽  
Champ Satellite ◽  
Incoherent Scatter

Abstract. Thermospheric drag is the major non-gravitational perturbation acting on Low Earth Orbit (LEO) satellites at altitudes up to 1000 km. The drag depends on the thermospheric density, which is a key parameter in the planning of LEO missions, e.g. their lifetime, collision avoidance, precise orbit determination, as well as orbit and re-entry prediction. In this study, we present an empirical model, named CH-Therm-2018, of the thermospheric mass density derived from 9-year (from August 2000 to July 2009) accelerometer measurements at altitude from 460 to 310 km, from the CHAllenging Minisatellite Payload (CHAMP) satellite. The CHAMP dataset is divided into two 5-year periods with 1-year overlap (from August 2000 to July 2005 and from August 2004 to July 2009), to represent the high-to-moderate and moderate-to-low solar activity conditions, respectively. The CH-Therm-2018 model is a function of seven key parameters, including the height, solar flux index, season (day of year), magnetic local time, geographic latitude and longitude, as well as magnetic activity represented by the solar wind merging electric field. Predictions of the CH-Therm-2018 model agree well with the CHAMP observations (disagreements within ±20 %), and show different features of thermospheric mass density during solar activities, e.g. the March-September equinox asymmetry and the longitudinal wave pattern. We compare the CH-Therm-2018 predictions with the Naval Research Laboratory Mass Spectrometer Incoherent Scatter Radar Extended (NRLMSISE-00) model. The result shows that CH-Therm-2018 better predicts the density evolution during the last solar minimum (2008-2009) than the NRLMSISE-00 model. By comparing the Satellite Laser Ranging (SLR) observations of the ANDE-Pollux satellites during August-September 2009, we estimate 6-h scaling factors of thermospheric mass density and obtain a median value of 1.27 ± 0.60, indicating that our model, on average, slightly underestimates the thermospheric mass density at solar minimum.

ELECTRON TEMPERATURE IN THE EQUATORIAL E REGION MEASURED BY TWO ROCKET EXPERIMENTS AND BY INCOHERENT SCATTER

1978 ◽  
pp. 265-268 ◽  
Author(s):  
L.G. Smith ◽  
R.K. Zimmerman ◽  
K. Hirao ◽  
K. Oyama ◽  
C. Calderon
Keyword(s):  
Electron Temperature ◽  
Incoherent Scatter ◽  
E Region

scholarly journals Cosmic radio noise absorption events associated with equatorward drifting arcs during a substorm growth phase

2004 ◽  
Vol 22 (5) ◽  
pp. 1675-1686 ◽  
Author(s):  
J. R. T. Jussila ◽  
A. T. Aikio ◽  
S. Shalimov ◽  
S. R. Marple
Keyword(s):  
Electron Temperature ◽  
Electric Fields ◽  
Growth Phase ◽  
Energetic Electron ◽  
Cosmic Radio ◽  
Radio Noise ◽  
Particle Precipitation ◽  
Noise Absorption ◽  
D Region ◽  
E Region

Abstract. Cosmic radio noise absorption (CNA) events associated with equatorward drifting arcs during a substorm growth phase are studied by using simultaneous optical auroral, IRIS imaging riometer and EISCAT incoherent scatter radar measurements. The CNA is generally attributed to energetic particle precipitation in the D-region. However, it has been argued that plasma irregularities or enhanced electron temperature (Te) in the E-region could also produce CNA. Both of the latter mechanisms are related to intense electric fields in the ionosphere. We present two events which occur during a substorm growth phase in the evening MLT sector. In both of the events, an auroral arc is drifting equatorward, together with a region of CNA (auroral absorption bay) located on the equatorward side and outside of the arc. Both of the events are associated with enhanced D-region electron density on the equatorward side of the auroral arc, but in the second event, a region of intense electric field and enhanced electron temperature in the E-region is also located on the equatorward side of the arc. We show that in the studied events neither plasma instabilities nor enhanced Te play a significant role in producing the measured CNA, but the CNA in the vicinity of the equatorward drifting arcs is produced by D-region energetic electron precipitation. Key words. Ionosphere (auroral ionosphere; particle precipitation; electric fields and currents)

An empirical model of electron temperature for low and middle latitudes in the 100–200 km height region

1985 ◽  
Vol 5 (7) ◽  
pp. 65-68 ◽  
Author(s):  
Yu.K. Chasovitin ◽  
N.M. Klyueva ◽  
L.S. Mironova ◽  
P.F. Denisenko ◽  
V.V. Sotsky ◽  
...  
Keyword(s):  
Electron Temperature ◽  
Empirical Model ◽  
Middle Latitudes

Comparison of plasma-density and electron-temperature profiles during the auroral modelling campaign ARIES

1991 ◽  
Vol 69 (8-9) ◽  
pp. 950-958 ◽  
Author(s):  
Joëlle Margot ◽  
A. G. McNamara
Keyword(s):  
Electron Temperature ◽  
Plasma Density ◽  
High Energy ◽  
Primary Electron ◽  
Temperature Profiles ◽  
Height Distribution ◽  
Optical Intensity ◽  
High Energy Electron ◽  
E Region ◽  
Primary Electrons

Plasma-density and electron-temperature profiles were measured during the auroral modelling campaign ARIES. This campaign consisted of two rockets launched in the auroral E region under different geophysical conditions. The plasma-density and electron-temperature behaviours were tentatively related to the energy and intensity of the ionizing primary-electron fluxes. It is concluded that the plasma-density height distribution can be used to estimate the primary-electrons energy. The set of data presented is sufficiently complete to allow, when used together with other types of experiments such as the height distribution of the optical intensity and the high-energy electron spectra, the achievement of the objective of the ARIES multi-instrument campaign, i.e., refinement of the auroral model.

scholarly journals AIM-E auroral ionosphere model adjustment for the regular E layer

2021 ◽  
Vol 7 (1) ◽  
pp. 41-46
Author(s):  
Vera Nikolaeva ◽  
Evgeniy Gordeev ◽  
Denis Rogov ◽  
Aleksandr Nikolaev
Keyword(s):  
Electron Density ◽  
Input Parameter ◽  
Magnetic Activity ◽  
Auroral Zone ◽  
Auroral Ionosphere ◽  
Solar Radio Flux ◽  
Ionosphere Model ◽  
E Region ◽  
Ap Index ◽  
Euv Spectrum

The E-Region Auroral Ionosphere Model (AIM-E) was developed to determine the chemical composition and electron density in the auroral zone at E-layer heights (90–150 km). Solar and magnetic activity input parameters for AIM-E are the three-hour Ap index and the daily solar radio flux at a wavelength of 10.7 cm (index F10.7). In this paper, we compare AIM-E calculations of the electron density for the daytime with EUV radiation spectrum specified in two different ways: 1) the EUV spectrum theoretically calculated using the F10.7 index as an input parameter; 2) using TIMED satellite direct measurements of the EUV spectrum. We have corrected the EUVAC EUV radiation model to specify a photoionization source in AIM-E. Calculations of regular E-region critical frequencies show good agreement with the vertical sounding data from Russian high-latitude stations. Results we obtained make it possible to do a quick on-line assessment of the regular E layer, using the daily index F10.7 as an input parameter.

scholarly journals Signatures of 2-day wave in the E-region electric fields and their relationship to winds and ionospheric currents

2009 ◽  
Vol 27 (2) ◽  
pp. 631-638 ◽  
Author(s):  
H. C. Aveiro ◽  
C. M. Denardini ◽  
M. A. Abdu
Keyword(s):  
Electric Fields ◽  
Magnetic Activity ◽  
Ionospheric Currents ◽  
Coherent Scatter ◽  
Meridional Winds ◽  
Magnetometer Data ◽  
E Region ◽  
Dip Equator ◽  
Ionospheric Electric Field ◽  
Coherent Radar

Abstract. We analyze the effects of the 2-day wave activity in the EEJ using one coherent scatter radar and eight magnetometer stations located close to the dip equator. The wavelet analysis of the magnetometer data reveals a 2-day signature in the semidiurnal geomagnetic tide. The E-region zonal background ionospheric electric field, derived from coherent radar measurements, shows 2-day oscillations in agreement with such oscillations in the magnetometers data. An anticorrelation between the amplitude of the tidal periodicites (diurnal and semidiurnal) and that of the 2-day signature is also shown in the electric fields. The results are compared with simultaneous observations of 2-day planetary wave in meridional winds and ionosonde data. Further, our results are discussed based on the analysis of the magnetic activity.

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