EMHD response of a magnetoplasma to an external current source

Summary form only given. The spatial and temporal evolution of electrojet modulation, and the ELF/VLF signal produced by ionospheric modification, is currently being studied in support of a planned experiment using the HAARP phased-array ionospheric heater. Theory and simulation concentrated on the EMHD response of the magnetoplasma to an applied current pulse. The collisionless case for zero-mass electrons is solved analytically. For finite electron mass, the response equations are solved by means of a numerical EMHD field solver. In the collisional case, a treatment using the Fokker-Planck equation, with the corresponding Ito stochastic differential equations, is planned. One requirement in optimizing the ELF/VLF generation efficiency is knowledge of the electron density profile in the modified region. The Artificial Periodic Irregularities (API) technique has been successful in reconstructing electron density profiles in the E-Region at Sura and Tromso, but has not yet been implemented at HAARP. Details and results of the HAARP experiment is discussed.