Title :
An adjoint method based approach to data assimilation for a distributed parameter model for the ionosphere
Author :
Rosen, I.G. ; Wang, C. ; Hajj, G. ; Pi, X. ; Wilson, B.
Author_Institution :
Dept. of Math., Univ. of Southern California, Los Angeles, CA, USA
Abstract :
A computational method for the estimation of the forces (drivers) which enter into the collisional plasma hydrodynamic equations for the ionosphere is developed. The ionospheric model used in this effort is for mid- and low-latitudes and consists of solving the continuity and momentum partial differential equations in four dimensions (three spatial dimensions and time) to compute the O+ density in the ionosphere and plasmasphere. We have developed codes for solving the forward model on a fixed grid and for solving the adjoint equations used in computing the gradients required for the estimation of the unknown driving forces. We describe our nonlinear least squares formulation of the data assimilation problem for the identification of the E×B drift and our development of the adjoint method for the computation of the requisite gradients
Keywords :
atmospheric composition; distributed parameter systems; geophysics computing; gradient methods; identification; ionosphere; least squares approximations; magnetosphere; optimisation; oxygen; O; collisional plasma hydrodynamic equations; distributed parameter model; driving forces; gradients; identification; ionospheric modeling; nonlinear least squares; optimization; partial differential equations; Data assimilation; Electrons; Equations; Extraterrestrial measurements; Hydrodynamics; Ionosphere; Plasma density; Plasma temperature; Predictive models; Wind;
Conference_Titel :
Decision and Control, 2001. Proceedings of the 40th IEEE Conference on
Conference_Location :
Orlando, FL
Print_ISBN :
0-7803-7061-9
DOI :
10.1109/.2001.980895
