Year: 2024
Type: article
Abstract: An expression of Rayleigh‐Taylor (R‐T) instability growth rate based on the field‐line integrated theory is newly established. This expression can be directly utilized in ionosphere models with magnetic flux tube structure based on Modified Apex Coordinates. The R‐T instability growth rates are calculated using the thermospheric and ionospheric conditions based on the coupled Whole Atmosphere Model and Ionosphere Plasmasphere Electrodynamic model (WAM‐IPE). The parameters used in this calculation include the field‐line integrated conductivities and currents, which consider the Quasi‐Dipole Coordinates and the modifications to the equations of electrodynamics. Detailed description of the new formulas and comprehensive analyses of diurnal, longitudinal, and seasonal variations of the R‐T instability growth rate are carried out. The dependencies of growth rates on pre‐reversal enhancement (PRE) vertical drifts and solar activity are also examined. The results show that pronounced R‐T growth rates are captured between 18 and 22 local time (LT) when strong PRE occurs in the equatorial ionosphere. The simulated R‐T growth rate increases with increasing solar activity levels and demonstrates strong correlations with the angle between the sunset terminator and the geomagnetic field line. These results are consistent with plasma irregularity occurrence rates shown in various satellite observations, suggesting that the newly developed R‐T growth rate calculation can effectively capture the probability of irregularities by considering the changes along magnetic flux‐tubes in the ionosphere. Since the WAM‐IPE is running in operation at National Oceanic and Atmospheric Administration Space Weather Prediction Center, the new calculations can be potentially implemented in the near future to provide forecasted information of the R‐T growth rate.
DOI: 10.1029/2024ja032550
Institutions: Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, National Central University, National Oceanic and Atmospheric Administration, NOAA Space Weather Prediction Center, NSF National Center for Atmospheric Research, NSF NCAR High Altitude Observatory
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: SWQU: Forecasting Small-Scale Plasma Structures in Earth's Ionosphere-Thermosphere System, The Management and Operation of the National Center for Atmoshperic Research (NCAR), A Study of Seismo-Ionospheric Precursors by Using Satellite Observations( I ), THE MAIN GOAL OF THIS PROPOSAL IS TO QUANTITATIVELY CHARACTERIZE STORM-TIME IONOSPHERIC ELECTRODYNAMICS BASED ON VARIOUS SPACE AND GROUND BASED OBSERVATIONS TOGETHER WITH ADVANCED DATA ASSIMILATION TECHNIQUES AND NUMERICAL SIMULATIONS. THIS INVESTIGATION WILL MAKE EXTENSIVE USE OF DATA FROM BOTH CURRENT AND PAST NASA MISSIONS INCLUDING TIMED IMAGE AND POLAR LEVERAGED BY OTHER SPACE AND GROUND BASED OBSERVATIONS IN ORDER TO OBTAIN THE MOST REALISTIC SPECIFICATION OF GLOBAL IONOSPHERIC ELECTRODYNAMIC FIELDS UNDER DIFFERENT SOLAR WIND AND GEOMAGNETIC CONDITIONS BY APPLYING THE ASSIMILATIVE MAPPING OF IONOSPHERIC ELECTRODYNAMICS (AMIE) PROCEDURE. WE WILL ALSO USE THE THERMOSPHERE-IONOSPHERE- ELECTRODYNAMICS GENERAL CIRCULATION MODEL (TIEGCM) TO DELINEATE THE VARIOUS PHYSICAL PROCESSES AFFECTING THE THERMOSPHERE. NUMERICAL EXPERIMENTS WILL BE CONDUCTED TO DETERMINE HOW THE DIFFERENT SPECIFICATIONS OF IONOSPHERIC ELECTRODYNAMIC FIELDS AFFECT THERMOSPHERIC DYNAMICS GLOBALLY., G6901529266
OpenAlex ID: W4401493204