Day-to-day changes in experimental electron density profiles and their implications to IRI model

2004 ◽  
Vol 34 (9) ◽  
pp. 1878-1886 ◽  
Author(s):  
G. Miró Amarante ◽  
M. Cueto Santamaría ◽  
M. Mosert de González ◽  
S.M. Radicella ◽  
R. Ezquer
Keyword(s):  
Electron Density ◽  
Iri Model ◽  
Density Profiles ◽  
Electron Density Profiles ◽  
Experimental Electron Density

scholarly journals Comparative study of electron density from incoherent scatter measurements at Arecibo with the IRI-95 model during solar maximum

2000 ◽  
Vol 18 (12) ◽  
pp. 1630-1634 ◽  
Author(s):  
N. K. Sethi ◽  
V. K. Pandey
Keyword(s):  
Electron Density ◽  
Solar Maximum ◽  
Iri Model ◽  
Bottom Part ◽  
Density Profiles ◽  
Incoherent Scatter ◽  
F Region ◽  
Electron Density Profiles ◽  
Thickness Parameter ◽  
Modelling And Forecasting

Abstract. Arecibo (18.4 N, 66.7 W) incoherent scatter (IS) observations of electron density N(h) are compared with the International Reference Ionosphere (IRI-95) during midday (10–14 h), for summer, winter and equinox, at solar maximum (1981). The N(h) profiles below the F2 peak, are normalized to the peak density NmF2 of the F region and are then compared with the IRI-95 model using both the standard B0 (old option) and the Gulyaeva-B0 thickness (new option). The thickness parameter B0 is obtained from the observed electron density profiles and compared with those obtained from the IRI-95 using both the options. Our studies indicate that during summer and equinox, in general, the values of electron densities at all the heights given by the IRI model (new option), are generally larger than those obtained from IS measurements. However, during winter, the agreement between the IRI and the observed values is reasonably good in the bottom part of the F2 layer but IRI underestimates electron density at F1 layer heights. The IRI profiles obtained with the old option gives much better results than those generated with the new option. Compared to the observations, the IRI profiles are found to be much thicker using Gulyaeva-B0 option than using standard B0.Key words: Ionosphere (modelling and forecasting)

scholarly journals Vertical electron density and topside effective scale height (<I>H</I><sub>T</sub>) variations over the Indian equatorial and low latitude stations

2011 ◽  
Vol 29 (10) ◽  
pp. 1861-1872 ◽  
Author(s):  
K. Venkatesh ◽  
P. V. S. Rama Rao ◽  
P. L. Saranya ◽  
D. S. V. V. D. Prasad ◽  
K. Niranjan
Keyword(s):  
Diurnal Variation ◽  
Electron Density ◽  
Scale Height ◽  
Electron Content ◽  
Iri Model ◽  
Night Time ◽  
Low Latitude ◽  
Density Profiles ◽  
Gps Tec ◽  
Electron Density Profiles

Abstract. Understanding the vertical electron density profile, which is the altitudinal variation of ionospheric electron density distribution is an important aspect for the ionospheric investigations. In this paper, the bottom-side electron density profiles derived from ground based ionosonde data and the ROCSAT-1 in-situ electron density data were used to determine the estimates of the topside electron density profiles using α-Chapman function over an equatorial station Trivandrum (8.47° N, 76.91° E) and a low latitude station Waltair (17.7° N, 83.3° E) in the Indian region. The reconstructed electron density profiles are compared with IRI (2007) model derived vertical electron density profiles which resulted in significant deviations between the two different profiles. Both the reconstructed electron density profiles and the IRI model derived profiles are integrated independently to derive the Total Electron Content (TEC) values which are compared with GPS derived TEC values. TEC values derived from the reconstructed electron density profiles give better estimates with the GPS-TEC compared to those of IRI model derived TEC values. Compared to the GPS-TEC, the IRI model is underestimating the TEC values during day-time and is overestimating during night-time at both the stations. The percentage deviations of IRI derived TEC from GPS-TEC are larger compared to those between reconstructed profile derived TEC and GPS-TEC. F2-layer peak electron density, peak height and electron density at ROCSAT altitudes (≈600 km) are used to derive the effective scale heights (HT) of the topside ionosphere during the period from July 2003 to June 2004. The diurnal and seasonal variations of HT and E×B drift velocities are presented in this paper. The diurnal variation of the effective scale height (HT) shows peak values around noon hours with higher values during day-time and lower values during night-time both at Trivandrum and Waltair. The E×B drift velocities at both the places also have shown a clear diurnal variation with a negative peak around 04:00 LT and maximum during day-time hours. The higher and lower values of HT seem to be associated with positive and negative phases of the E×B drift velocities, respectively.

scholarly journals The IRI topside parameters

2005 ◽  
Vol 2 ◽  
pp. 249-251 ◽  
Author(s):  
P. Coïsson ◽  
S. M. Radicella
Keyword(s):  
Electron Density ◽  
Wide Spectrum ◽  
Critical Conditions ◽  
High Solar Activity ◽  
Constitutive Parameter ◽  
Iri Model ◽  
Density Profiles ◽  
Electron Density Profiles ◽  
Very High

Abstract. The IRI electron density topside has been constructed on the basis of the data available about thirty years ago. Recently a large amount of data from old topside sounders have been processed to get electron density profiles. These profiles allow to test IRI model under a wide spectrum of different conditions and to understand the behavior of the modeled topside. A set of 12 000 topside profiles have been chosen from the ISIS2 database, selecting those with the better quality of the inverted profile. An analysis of each IRI topside constitutive parameter has been done for all the experimental cases allowing to find some critical conditions under which the IRI topside could become completely unrealistic. In particular for very high solar activity at high latitudes it has been found that some IRI parameters could reach values that change drastically the shape of IRI topside. A proposal to control their range of variability is formulated in order to avoid the occurrence of such cases.

Electron density profiles above the F-layer

1973 ◽  
Vol 21 (9) ◽  
pp. 1581-1586
Author(s):  
Michael Anastassiadis ◽  
Georges Moraitis ◽  
Dimitris Matsoukas
Keyword(s):  
Electron Density ◽  
Density Profiles ◽  
Electron Density Profiles
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