CLIMATE MODEL (GCM) MOLA TOPOGRAPHY A MODEL OF THE THERMAL EVOLUTION OF THE CRUST AND AN ADVANCED MODEL OF REGIONAL AND GLOBAL SUBPERMAFROST GROUNDWATER FLOW (BASED ON THE LATEST UNSTRUCTURED GRID (USG) IMPLEMENTATION OF THE US GEOLOGICAL SURVEY S GROUNDWATER MODELING SOFTWARE MODFLOW) TO INVESTIGATE THE EFFECTS OF A COLD EARLY CLIMATE ON THE EVOLUTION OF THE MARTIAN HYDROSPHERE THE FIRST ATTEMPT TO SIMULATE THE COMPLETE HYDROLOGIC CYCLE OF A COLD EARLY MARS. THIS IS WORK THAT IS BEING PURSUED IN COLLABORATION WITH CO-I ROBIN WORDSWORTH (HARVARD UNIVERSITY). THIS REVISED PROPOSAL IS BEING SUBMITTED BECAUSE OF MY TRANSITION FROM THE LUNAR AND PLANETARY INSTITUTE (LPI) TO THE PLANETARY SCIENCE INSTITUTE (PSI) AND INCLUDES A DISCUSSION OF THE TASKS I INTEND TO PURSUE AT PSI IN THE REMAINING TWO YEARS OF THIS GRANT (SECTION 2.1) AS WELL AS THE PROGRESS THAT WAS MADE AT LPI DURING THE GRANT S FIRST YEAR (SECTION 2.3). THIS PROPOSAL ALSO CONTAINS A REVISED BUDGET FOR YEAR S 2&3 (SECTION VII) THAT INCLUDES A CARRY-OVER OF UNSPENT FUNDS FROM THE FIRST YEAR AT LPI.