Impacts of solar activity on performance of the IRI-2012 model predictions from low to mid latitudes

Kumar, Sanjay; Tan, Eng Leong; Murti, Dhimas Sentanu

doi:10.1186/s40623-015-0205-3

Cited by 61 publications

(51 citation statements)

References 52 publications

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“…In addition, the model performance in estimating diurnal VTEC variations was found to be better during low solar activity phases than during high solar activity phases. Abdu et al (1996), Kakinami et al (2012), Kumar et al (2015), andMcNamara (1985) attempted to describe the model's capacity to estimate the TEC in low-and mid-latitude regions. However, so far nobody has conducted a study to investigate patterns of VTEC variation over Ethiopian regions during the rising phase of solar cycle 24.…”

Section: Introductionmentioning

confidence: 99%

TEC prediction performance of the IRI-2012 model over Ethiopia during the rising phase of solar cycle 24 (2009–2011)

Tariku

2015

Earth Planet Sp

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This paper discusses the performance of the latest version of the International Reference Ionosphere (IRI-2012) model for estimating the vertical total electron content (VTEC) variation over Ethiopian regions during the rising phase of solar cycle 24 (2009-2011). Ground-based Global Positioning System (GPS) VTEC data, inferred from dual-frequency GPS receivers installed at Bahir Dar (geographic latitude 11.6°N and longitude 37.35°E, geomagnetic latitude 2.64°N and longitude 108.94°E), Nazret (geographic latitude 8.57°N and longitude 39.29°E, geomagnetic latitude −0.25°N and longitude 111.01°E), and Robe (geographic latitude 7.11°N and longitude 40.03°E, geomagnetic latitude −1.69°N and longitude 111.78°E), are compared to diurnal, monthly, and seasonal VTEC variations obtained with the IRI-2012 model. It is shown that the variability of the diurnal VTEC is minimal at predawn hours (near 0300 UT, 0600 LT) and maximal between roughly 1000 and 1300 UT (1300-1600 LT) for both the experimental data and the model. Minimum seasonal VTEC values are observed for the June solstice during the period of 2009-2011. Moreover, it is shown that the model better estimates diurnal VTEC values just after the midnight hours (0000-0300 UT, 0300-0600 LT). The modeled monthly and seasonal VTEC values are larger than the corresponding measured values during the period of 2009-2010 when all options for the topside electron density are used. An important finding of this study is that the overestimation of VTEC values derived from the model decreases as the Sun transitions from very low to high solar activity. Moreover, it is generally better to use the model with the NeQuick option for the topside electron density when estimating diurnal, monthly, and seasonal VTEC variations.

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Section: Introductionmentioning

confidence: 99%

TEC prediction performance of the IRI-2012 model over Ethiopia during the rising phase of solar cycle 24 (2009–2011)

Tariku

2015

Earth Planet Sp

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“…The IRI model provides many parameters, including Total Electron Content (TEC) electron density, ion and electron temperature, ion composition for a given latitude, longitude, time date at altitudes ranging from 60 km to 2000 km. IRI based TEC data is derived by integrating the electron density profile from the lower boundary to the user specified upper boundary [Kumar et al 2015]. In this study, in order to compute IRI_2012 TEC values, a web interface from the IRI homepage (URL-3) was used.…”

Section: Model Calculations 211 Iri_2012mentioning

confidence: 99%

Comparison of IRI_PLAS and IRI_2012 Model Predictions with GPS-TEC Measurements in Different Latitude Regions

Alçay¹,

Öztan²,

Selvi³

2017

Annals of Geophysics

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“…5 and 6, we determined the uncertainties in the conductivity and the EEF associated with the empirical model outputs in order to precisely determine the confidence limit in their magnitude. Although a large number of works deal with the comparisons between neutral atmosphere data and MSIS model prediction (Richards 2002;Liu et al 2005;Burke et al 2007;Park et al 2008;Jeon et al 2011), observed ionospheric data and IRI model predictions Batista et al 1996;de Souza et al 2003;Sethi et al 2004;Bertoni et al 2006;Lühr and Xiong 2010;Kenpankho et al 2011;Oyekola and Fagundes 2012;Yue et al 2013;Kumar et al 2014Kumar et al , 2015, and geomagnetic field data and IGRF predictions (Lowes 2000;Lowes and Olsen 2004), uncertainties (or potential errors) of these empirical models have not been published, even in Bilitza and Reinisch (2008), Picone et al (2002), and Finlay et al (2010).…”

Section: Analysis Of Linear Fittingmentioning

confidence: 99%

Influence of uncertainties of the empirical models for inferring the E-region electric fields at the dip equator

et al. 2016

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Daytime E-region electric fields play a crucial role in the ionospheric dynamics at the geomagnetic dip latitudes. Due to their importance, there is an interest in accurately measuring and modeling the electric fields for both climatological and near real-time studies. In this work, we present the daytime vertical (Ez) and eastward (Ey) electric fields for a reference quiet day (February 7, 2001) at the São Luís Space Observatory, Brazil (SLZ, 2.31°S, 44.16°W). The component Ez is inferred from Doppler shifts of type II echoes (gradient drift instability) and the anisotropic factor, which is computed from ion and electron gyro frequencies as well as ion and electron collision frequencies with neutral molecules. The component Ey depends on the ratio of Hall and Pedersen conductivities and Ez. A magnetic field-line-integrated conductivity model is used to obtain the anisotropic factor for calculating Ez and the ionospheric conductivities for calculating Ey. This model uses the NRLMSISE-00, IRI-2007, and IGRF-11 empirical models as input parameters for neutral atmosphere, ionosphere, and geomagnetic field, respectively. Consequently, it is worth determining the uncertainties (or errors) in Ey and Ez associated with these empirical model outputs in order to precisely define the confidence limit for the estimated electric field components. For this purpose, errors of ±10 % were artificially introduced in the magnitude of each empirical model output before estimating Ey and Ez. The corresponding uncertainties in the ionospheric conductivity and electric field are evaluated considering the individual and cumulative contribution of the artificial errors. The results show that the neutral densities and temperature may be responsible for the largest changes in Ey and Ez, followed by changes in the geomagnetic field intensity and electron and ions compositions.

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Impacts of solar activity on performance of the IRI-2012 model predictions from low to mid latitudes

Abstract: This study investigates the impacts of solar activity on the performance of the latest release of International Reference Ionosphere (IRI) model version 2012 (IRI-2012)

Cited by 61 publications

References 52 publications

TEC prediction performance of the IRI-2012 model over Ethiopia during the rising phase of solar cycle 24 (2009–2011)

TEC prediction performance of the IRI-2012 model over Ethiopia during the rising phase of solar cycle 24 (2009–2011)

Comparison of IRI_PLAS and IRI_2012 Model Predictions with GPS-TEC Measurements in Different Latitude Regions

Influence of uncertainties of the empirical models for inferring the E-region electric fields at the dip equator

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