SCIENCE OBJECTIVES: ATMOSPHERIC ESCAPE AT TERRESTRIAL PLANETS HAS BEEN THE SUBJECT OF INTENSE INTEREST BECAUSE OF THE IMPLICATIONS FOR PAST AND PRESENT WATER RESERVOIRS AS WELL AS THE EVOLUTION OF ATMOSPHERIC VOLATILES AND THEIR INVENTORIES. AT MARS WHERE THE EXOSPHERE IS DIRECTLY EXPOSED TO THE SOLAR WIND BECAUSE IT LACKS A DIPOLE MAGNETIC FIELD PLANETARY NEUTRALS CAN BE IONIZED AND SUBSEQUENTLY 'PICKED UP' BY THE BACKGROUND CONVECTION ELECTRIC FIELD AND SWEPT AWAY. THESE PICKUP IONS CAN EITHER DIRECTLY ESCAPE OR PRECIPITATE BACK INTO THE ATMOSPHERE. IN THE LATTER CASE PRECIPITATING PICKUP IONS SERVE AS A CATALYST FOR THE ATMOSPHERIC ESCAPE PROCESS SPUTTERING . THIS OCCURS WHEN ENERGIZED PICKUP IONS COLLIDE WITH NEUTRALS NEAR THE EXOBASE AND TRANSFER ENOUGH ENERGY FOR THE NEUTRALS TO EXCEED THE ESCAPE VELOCITY. CURRENTLY ATMOSPHERIC SPUTTERING IS DIFFICULT TO MEASURE BECAUSE THE PREDICTED YIELDS ARE ALMOST AN ORDER OF MAGNITUDE BELOW THAT OF OTHER NONTHERMAL ATMOSPHERIC ESCAPE PROCESSES. BUT UNDER THE MORE EXTREME CONDITIONS EXPECTED TO EXIST FOR AN EARLIER STAGE OF THE SUN WHEN IT WAS MORE ACTIVE SPUTTERING MAY HAVE BEEN THE DOMINANT ATMOSPHERIC LOSS PROCESS AT MARS AND VENUS. SUCH SPECULATIONS ARE IN PART MOTIVATED BY LACK OF OTHER MECHANISMS FOR EXPLAINING PRESENT HEAVY ELEMENT (E.G. ARGON) ISOTOPE RATIOS. THE GOAL OF THE PROPOSED STUDY IS TO EXECUTE NUMERICAL SIMULATIONS OF THE EXTREME SOLAR WIND INTERACTION WITH MARS TO INVESTIGATE WHAT THE SPUTTERING YIELD IS AND IF IT CAN BE OBSERVED. METHODOLOGY: WE PROPOSE TO STUDY THE EROSION OF MARS ATMOSPHERE VIA SPUTTERING BY SIMULATING BOTH OBSERVED AND IDEALIZED SPACE WEATHER EVENTS THAT MIRROR THE EXTREME CONDITIONS THOUGHT TO EXIST DURING AN EARLY STAGE OF THE SOLAR SYSTEM AND SUN S EVOLUTION. WE HAVE SELECTED THE JULY 2000 BASTILLE DAY STORM THE OCTOBER 2003 HALLOWEEN STORM AND THE JULY 2012 STORM. ALL THREE EVENTS INCLUDED ICMES WHICH HAVE BEEN SHOWN TO SIGNIFICANTLY ENHANCE ATMOSPHERIC ESCAPE. ADDITIONALLY WE HAVE CHOSEN SOLAR WIND CONDITIONS FOR THREE IDEALIZED STORMS TO REPRESENT DECADAL CENTURY AND MILLENNIAL SPACE WEATHER EVENTS. ALL OF THESE ICMES WILL BE COMPARED TO THE MARCH 8TH 2015 ICME OBSERVED BY MAVEN. WE WILL USE THE 3D GLOBAL EXOSPHERIC MODEL (EGM) AND THE 3D PARALLEL HYBRID MODEL (LATHYS) TO SELF-CONSISTENTLY SIMULATE THE PLASMA ENVIRONMENT AND THE SPUTTERED YIELDS FOR EACH STORM. THESE MODELS HAVE BEEN DEVELOPED OVER THE LAST DECADE BY OUR COLLABORATORS AND ARE RUN USING A PARALLEL GRID. THE EGM MODEL DESCRIBES THE UPPER ATMOSPHERE OF MARS AND THE LATHYS MODEL DESCRIBES THE PHYSICAL PLASMA PROCESSES ASSOCIATED WITH THE SOLAR WIND INTERACTION WITH THE ATMOSPHERE IONOSPHERE AND CRUSTAL MAGNETIC FIELDS INCLUDING FINITE ION GYRORADIUS EFFECTS. USING THE SIMULATED STORM RESULTS WE WILL CALCULATE THE SPUTTERING YIELDS FOR EACH CASE AND PERFORM SYNTHETIC SPACECRAFT FLY-THROUGHS OF THE ATMOSPHERE IN ORDER TO DETERMINE IF THE SPUTTERED YIELDS COULD BE DETECTED AT MARS. THE ONLY ADAPTATIONS TO THE EGM AND LATHYS MODELS ARE TO MOVE THEM TO THE NASA PLEIADES PLATFORM (TIER -0) FROM THE CURRENT LOCAL CLUSTER (TIER-2). RELEVANCE: THE PROPOSED WORK IS HIGHLY RELEVANT AND WOULD PROVIDE NEW INSIGHT INTO THE STILL UNRESOLVED IMPORTANCE OF THE SPUTTERING PROCESS IN PLANETARY ATMOSPHERE EVOLUTION. ITS OUTCOME RELATES TO THE SCIENCE OF MARS AND VENUS EXPRESS MAVEN AND CASSINI MISSIONS AND TO RECENT STUDIES ON EXOPLANET ATMOSPHERE EROSION. IT ALSO DIRECTLY ADDRESSES THE ROSES SSW FOCUS OF COMPOSITION / EVOLUTION AS WELL AS DYNAMICS/THERMAL STRUCTURE. ADDITIONALLY NASA S PLEIADES SUPERCOMPUTER SYSTEM ON WHICH THE PI IS AN EXPERIENCED USER IS A PLATFORM ON WHICH THESE SIMULATIONS WOULD BE EXECUTED. THE PROPOSED TEAM HAS EXPERIENCE WORKING TOGETHER ON MODELING MARS ATMOSPHERE BUT IS NOT SUPPORTED TO CARRY OUT ANY OF THE PROPOSED WORK.