Year: 2003
Type: report
Abstract: Our primary goal is to construct a real-time data assimilation model for the ionosphere-plasmasphere system that will provide reliable specifications and forecasts.A secondary goal is to validate the model for a wide range of geophysical conditions, including different solar cycle, seasonal, storm, and substorm conditions. OBJECTIVESWe propose to develop a software program that will provide for a Global Assimilation of Ionospheric Measurements (GAIM).GAIM will use a physics-based ionosphere-plasmasphere model as a basis for assimilating a diverse set of real-time (or near real-time) measurements.The program will provide specifications and forecasts on a specified spatial grid that can be global, regional, or local (50 km x 50 km).The specifications/forecasts will be in the form of 3-dimensional electron density distributions from 90 km to geosynchronous altitudes (35,000 km).Auxiliary plasma parameters will also be provided, such as N m F 2 , h m F 2 , N m E, h m E, and slant and vertical TEC.In its specification mode, GAIM will provide quantitative estimates for the accuracy of the reconstructed ionospheric densities.The measurements GAIM will assimilate include: (1) Slant path TECs between 80-90 ground receivers and the Global Positioning System (GPS) satellites; (2) Occultation data from a satellite constellation such as COSMIC; (3) TECs associated with the CIT network; (4) Bottomside N e profiles from digisondes associated with the Air Force DISS network; (5) In situ plasma parameters from the SSIES instrument package on the DMSP satellites; and (6) Line-of-sight UV emissions and deduced plasma parameters from the Naval Research Laboratory's SSUSI and SSULI instruments.GAIM will have a modular construction, so that new data types can be readily assimilated when they become available. APPROACHOur approach is to use a two-step process to obtain a 3-D ionospheric reconstruction.First, certain data sets will be assimilated so that the inputs (neutral parameters, electric fields, precipitation) to the physics-based ionosphere-plasmasphere model can be adjusted, within expected errors, to match observations, and then the physics-based model will be run in order to obtain a 3-D N e distribution that is consistent with the measured inputs.This first step should result in realistic ionospheric density features.Next, this simulated ionosphere-plasmasphere system will be used as a starting point for an electron density reconstruction using all of the different data types that pertain to N e and a Kalman filter assimilation technique.The use of a simulated ionosphere-plasmasphere system will provide
DOI: 10.21236/ada628805
Author: Robert W. Schunk
Institutions: Utah State University, Washington Headquarters Services
Language: English
Subfield: Space and Planetary Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W3000499447