THE INTERACTION OF THE SOLAR WIND WITH EARTH'S INTRINSIC MAGNETIC FIELD PRODUCES A MYRIAD OF MAGNETOSPHERIC CURRENTS. SINCE THE IONOSPHERE ACTS AS A CONDUCTOR TO THE CIRCULATION OF THESE CURRENTS THE IONOSPHERIC CONDUCTANCE BECOMES A CRUCIAL FACTOR FOR PREDICTIVE INVESTIGATIONS OF THE MAGNETOSPHERE - IONOSPHERE COUPLING DURING SPACE WEATHER EVENTS. WHILE SEVERAL MODELS HAVE ATTEMPTED TO ESTIMATE IT THE EXACT FACTORS DETERMINING THE CONDUCTANCE REMAIN UNCLEAR. THIS IMPEDES BOTH OUR UNDERSTANDING OF THE MAGNETOSPHEREIONOSPHERE SYSTEM DURING SPACE WEATHER EVENTS AND PREDICTIVE CAPABILITIES OF GROUND INDUCED CURRENTS WHICH POSE A SERIOUS THREAT TO MAN-MADE TECHNOLOGY. MAGNETOHYDRODYNAMIC (MHD) MODELING IS A POWERFUL AND WELL-ESTABLISHED TOOL FOR INVESTIGATING AND PREDICTING THE MAGNETOSPHERESOLAR WIND INTERACTION. USING MHD MODELING COUPLED WITH SUITABLE IONOSPHERIC AND INNER MAGNETOSPHERIC MODELS WE INTEND TO ADDRESS THE FOLLOWING FUNDAMENTAL QUESTIONS: Q1. HOW DO THE DIFFERENT SOURCES OF IONOSPHERIC CONDUCTANCE CONTRIBUTE TO THE OVERALL PATTERN AND HOW DOES THAT DEPEND ON SOLAR WIND CONDITIONS? Q2. WHAT ROLE DO THESE SOURCES OF CONDUCTANCE PLAY IN THE MAGNETOSPHERE-IONOSPHERE (MI) COUPLING ACROSS DIFFERENT STORM TYPES AND PHASES? Q3. HOW DO THESE DIVERSE SOURCES CONTRIBUTE TO SPACE WEATHER THREATS VIA GROUND INDUCED CURRENTS (GICS)? WE SEEK TO ANSWER THESE QUESTIONS BY CONDUCTING SYSTEMATIC NUMERICAL EXPERIMENTS WITH EXTENSIVE DATA-MODEL VALIDATION STUDIES. OUR PROPOSED MODEL WILL BE ABLE TO APPLY THE DIFFERENT SOURCES OF CONDUCTANCE INDIVIDUALLY AND IN COMBINATIONS USING A PHYSICS-BASED CONDUCTANCE MODEL TO HELP US INVESTIGATE THE ROLE OF ACCURATE CONDUCTANCE ESTIMATIONS IN FORECASTING GROUND INDUCED CURRENTS (GICS). OUR ULTIMATE GOAL WILL BE TO GAIN A SIGNIFICANTLY IMPROVED UNDERSTANDING OF THE IONOSPHERIC CONDUCTANCE AND ITS INTERACTION WITH THE MAGNETOSPHERE THROUGH A PHYSICS-BASED NUMERICAL MODEL WHICH CAN SERVE AS A PREDICTIVE TOOL IN SPACE WEATHER OPERATIONS. THIS WILL BE DIRECTLY ADDRESSING NASA HELIOPHYSICS RESEARCH PROGRAM'S GOAL TO ADDRESS THE SUN-EARTH LINK AND HELP DETECT MECHANISMS TO PREDICT CONDITIONS DURING EXTREME SPACE WEATHER TO PROTECT MAN-MADE TECHNOLOGY