NOACHIAN-AGED FLUVIAL FEATURES ON THE SURFACE OF MARS SUCH AS THE VALLEY NETWORKS AND OPEN- AND CLOSED-BASIN LAKES ARE EVIDENCE OF STABLE LIQUID WATER ON THE SURFACE AND HAVE LED SCIENTISTS TO BELIEVE THAT THE PLANET WAS ONCE WARM WITH MEAN ANNUAL TEMPERATURES (MATS) HIGH ENOUGH TO PERMIT RAINFALL AND PRODUCE AN ENVIRONMENT IN WHICH LIFE COULD FORM. HOWEVER CLIMATE MODELS HAVE BEEN INCAPABLE OF REPRODUCING THESE CONDITIONS AS THEY HAVE NOT FOUND A PLAUSIBLE COMBINATION OF GREENHOUSE GASES TO BRING MATS CONSISTENTLY ABOVE THE MELTING POINT OF WATER. CONSEQUENTIALLY WE ARE LEFT WITH TWO END-MEMBER CLIMATE SCENARIOS: (1) WARM AND WET CHARACTERIZED BY MAT ABOVE THE MELTING POINT OF WATER AND RAINFALL TO PERMIT FLUVIAL ACTIVITY AND (2) COLD AND ICY CHARACTERIZED BY MAT FAR BELOW THE MELTING POINT OF WATER. IN THE LATTER CLIMATE SCENARIO THE ATMOSPHERE AND SURFACE THERMALLY COUPLE INDUCING AN ALTITUDE-DEPENDENT TEMPERATURE EFFECT AND CAUSING SNOW TO DEPOSIT IN THE HIGHLANDS. INTERESTINGLY THE VALLEY NETWORKS AND LAKES ARE OBSERVED AT DISTAL PORTIONS OF THE ICE SHEET IN COLD AND ICY CONDITIONS WHERE RUNOFF AND PONDING IS EXPECTED FOLLOWING MELTING OF THE ICE SHEET. THREE END-MEMBER MECHANISMS FOR PRODUCING TRANSIENT HEATING IN A COLD AND ICY CLIMATE PERMITTING TRANSIENT MELTING OF THE ICE SHEET AND SUBSEQUENT RUNOFF INCLUDE IMPACT CRATERING VOLCANISM AND GREENHOUSE WARMING (E.G. H2 THROUGH SERPENTINIZATION). THE GOAL OF THIS WORK IS TO EXPLORE ALL THREE OF THESE MECHANISMS WITH THE LABORATORIE DE METEOROLOGIE GLOBAL CLIMATE MODEL (LMD GCM). WE WILL INTRODUCE ALL THREE MECHANISMS INTO THE GCM AND TEST THE APPLICABILITY OF THESE MECHANISMS FOR PRODUCING SUFFICIENT FLUVIAL AND LACUSTRINE ACTIVITY TO FORM THE VALLEY NETWORKS AND LAKES. SPECIFICALLY WE WILL FOCUS ON THE VOLUME DISTRIBUTION AND RUNOFF RATES OF (1) MELTWATER PRODUCED FROM TRANSIENT MELTING OF THE ICE SHEET AND (2) RAINFALL FOR MECHANISMS THAT RAISE TEMPERATURES SUFFICIENTLY TO INTRODUCE TRANSIENT RAINFALLS. ADDITIONALLY WE TEST ALL THREE MECHANISMS FOR A WIDE PARAMETER SPACE TO ENCOMPASS POSSIBLE EARLY MARS VALUES THUS BETTER CONSTRAINING THE ROLE OF THESE MECHANISMS: 600-1000 MBAR CO2 ATMOSPHERE 25-55 OBLIQUITY AND 0-0.1 ECCENTRICITY. WE PREDICT THAT ONE OR MORE OF THE MECHANISMS PROPOSED HERE MAY INCREASE TEMPERATURES ABOVE THE MELTING POINT OF WATER SUFFICIENTLY TO PRODUCE MELTING AND TO PRODUCE MELT DURATIONS AND FLUXES OR RAINFALL AND RUNOFF RATES COMPARABLE TO THOSE NECESSARY TO FORM THE FLUVIAL/LACUSTRINE FEATURES. ADDITIONALLY ALL THREE OF THE ANALYZED MECHANISMS ARE MAJOR DRIVING FORCES FOR THE EARLY MARS CLIMATE AND IT IS CRITICAL TO EXPLORE THE REGIONAL AND GLOBAL EFFECTS OF THESE MECHANISMS TO BETTER UNDERSTAND THE NATURE OF THE EARLY MARS CLIMATE. THROUGH THIS WORK WE WILL CONTRIBUTE TO UNDERSTANDING WHETHER THE FLUVIAL AND LACUSTRINE SURFACE FEATURES CAN BE FORMED IN A COLD AND ICY CLIMATE OR IF CONVERSELY A WARM AND WET CLIMATE MIGHT BE MORE LIKELY. BY CONTRIBUTING TO CONSTRAINING THE EARLY MARTIAN CLIMATE WE HELP TO DETERMINE IF THE CLIMATE WAS SUITABLE FOR THE BEGINNINGS OF MARTIAN LIFE A CRITICAL QUESTION FOR MARS SCIENCE. THIS WORK REFLECTS THE GOALS OF NASA AND THE PLANETARY SCIENCE SMD DIVISION AS IT CONTRIBUTES TO UNDERSTANDING THE ORIGIN EVOLUTION AND PROPERTIES OF THE ATMOSPHERE OF MARS WHICH PROVIDES IMPLICATIONS FOR THE POTENTIAL OF LIFE FORMING ON EARLY MARS AS WE CHARACTERIZE THE ATMOSPHERE AND CLIMATE SCENARIO. IN TURN THIS RESEARCH WILL ALSO HELP IN CHARACTERIZING OTHER PLANETARY SYSTEMS AND THEIR EVOLUTION THROUGH TIME.