TY - JOUR

T1 - AIM-E: E-Region Auroral Ionosphere Model

AU - Nikolaeva, Vera

AU - Gordeev, Evgeny

AU - Sergienko, Tima

AU - Makarova , Ludmila

AU - Kotikov , Andrey

N1 - Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

PY - 2021/6

Y1 - 2021/6

N2 - The auroral oval is the high-latitude region of the ionosphere characterized by strong variability of its chemical composition due to precipitation of energetic particles from the magnetosphere. The complex nature of magnetospheric processes cause a wide range of dynamic variations in the auroral zone, which are difficult to forecast. Knowledge of electron concentrations in this highly turbulent region is of particular importance because it determines the propagation conditions for the radio waves. In this work we introduce the numerical model of the auroral E-region, which evaluates density variations of the 10 ionospheric species and 39 reactions initiated by both the solar extreme UV radiation and the magnetospheric electron precipitation. The chemical reaction rates differ in more than ten orders of magnitude, resulting in the high stiffness of the ordinary differential equations system considered, which was solved using the high-performance Gear method. The AIM-E model allowed us to calculate the concentration of the neutrals NO, N(4S), and N(2D), ions N+, N2+, NO+, O2+, O+(4S), O+(2D), and O+(2P), and electrons Ne, in the whole auroral zone in the 90‒150 km altitude range in real time. The model results show good agreement with observational data during both the quiet and disturbed geomagnetic conditions.

AB - The auroral oval is the high-latitude region of the ionosphere characterized by strong variability of its chemical composition due to precipitation of energetic particles from the magnetosphere. The complex nature of magnetospheric processes cause a wide range of dynamic variations in the auroral zone, which are difficult to forecast. Knowledge of electron concentrations in this highly turbulent region is of particular importance because it determines the propagation conditions for the radio waves. In this work we introduce the numerical model of the auroral E-region, which evaluates density variations of the 10 ionospheric species and 39 reactions initiated by both the solar extreme UV radiation and the magnetospheric electron precipitation. The chemical reaction rates differ in more than ten orders of magnitude, resulting in the high stiffness of the ordinary differential equations system considered, which was solved using the high-performance Gear method. The AIM-E model allowed us to calculate the concentration of the neutrals NO, N(4S), and N(2D), ions N+, N2+, NO+, O2+, O+(4S), O+(2D), and O+(2P), and electrons Ne, in the whole auroral zone in the 90‒150 km altitude range in real time. The model results show good agreement with observational data during both the quiet and disturbed geomagnetic conditions.

KW - auroral oval

KW - E-region of ionosphere

KW - numerical modeling

KW - substorm

KW - ion composition

KW - electron concentration

KW - Auroral oval

KW - Numerical modeling

KW - Electron concentration

KW - Substorm

KW - Ion composition

KW - ENERGY

KW - O2

KW - DISSOCIATIVE RECOMBINATION

KW - TEMPERATURE-DEPENDENCE

KW - O(1D)

KW - THERMOSPHERE

KW - ATOMIC NITROGEN

KW - RATE CONSTANTS

KW - CHEMISTRY

KW - COEFFICIENTS

UR - http://www.scopus.com/inward/record.url?scp=85108438340&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/3887248f-0088-352f-8a76-25a7da08ebcc/

U2 - 10.3390/atmos12060748

DO - 10.3390/atmos12060748

M3 - Article

VL - 12

JO - ATMOSPHERE

JF - ATMOSPHERE

SN - 1598-3560

IS - 6

M1 - 748

ER -