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WHISTLERS ARE BURSTS OF EXTREMELY LOW FREQUENCY (ELF) AND VERY LOW FREQUENCY (VLF) WAVES THAT TRAVEL THROUGH THE PLASMASPHERE. DISPERSION CAUSES THE HIGHER FREQUENCY PORTION OF THE EMISSION TO ARRIVE BEFORE THE LOWER FREQUENCY CAUSING WHISTLE SOUND. WHISTLERS CAN BE TRIGGERED BY LIGHTNING STRIKES ELECTRON TEMPERATURE ANISOTROPY AND OTHER WAVE-WAVE OR WAVE-PARTICLE-WAVE INTERACTIONS. THE WAVES TRAVEL ALONG MAGNETIC FIELDS AND THE CHANGES THE WAVE UNDERGOES PROVIDES INFORMATION ABOUT THE ELECTRON DENSITY PATH LENGTH AND IONIZATION IN THE OUTER ATMOSPHERE. ADDITIONALLY THESE WAVES CAN ENERGIZE PARTICLES CAUSING ELECTRON ACCELERATION AND AIDING IN THE ESCAPE OF IONS (E.G. HELLIWELL 1965; DAVIES 1990) . ENERGETIC ELECTRON FLUX VARIATIONS HAVE BEEN OBSERVED TO VARY BY THREE ORDERS OF MAGNITUDE AT EARTH (BAKER ET AL. 1986 1997 1998A 1998B) AND SATELLITES HAVE BEEN DAMAGED BY THESE VARIATIONS (E.G. BAKER ET AL. 1998C; BAKER 2001; HORNE 2003) HORNE ET AL. 2005 THREE CASES OF WHISTLERS IN MARS MAGNETOSPHERE CAUSED BY CYCLOTRON RESONANCE WITH ELECTRON ANISOTROPY HAVE BEEN PRESENTED (HARADA ET AL. 2016). WE PROPOSE AN EXTENSIVE SEARCH FOR AND CHARACTERIZATION OF WHISTLERS IN THE ENTIRE MARTIAN PLASMA ENVIRONMENT. A NEURAL NETWORK WILL BE DEVELOPED TO AID IN THE ANALYSIS OF THE OVER THREE YEARS OF MARS ATMOSPHERE AND VOLATILE EVOLUTION (MAVEN) MAGNETOMETER (MAG) AND LANGMUIR PROBE AND WAVES (LPW) DATA. WE WILL SEARCH FOR WHISTLERS IN THE MARTIAN MAGNETOSPHERE BOW SHOCK AND IONOSPHERE. AN ANALYSIS OF THE SPATIAL AND TEMPORAL DISTRIBUTION OF WHISTLERS WILL PROVIDE CLUES FOR THE VARIOUS PROCESSES THAT MAY BE CAUSING THE WHISTLERS INCLUDING ELECTRON TEMPERATURE ANISOTROPY AND LIGHTNING. A COMPARISON BETWEEN MARS AND EARTH WHISTLER ACTIVITY MAY ALSO REVEAL IMPORTANT DIFFERENCES IN BEHAVIOR CAUSED BY MARS LACK OF AN INTRINSIC GLOBAL MAGNETIC FIELD. WE WILL BE ABLE TO DETERMINE THE EXTENT TO WHICH WHISTLERS AID IN PARTICLE ACCELERATION AND ION ESCAPE ON MARS. THIS IS IMPORTANT FOR UNDERSTANDING THE MARTIAN PLASMA ENVIRONMENT AND POTENTIAL DANGERS TO PRESENT AND FUTURE MISSIONS. THIS WORK WILL BE A COLLABORATION BETWEEN TRACY ESMAN (UNIVERSITY OF ARIZONA LUNAR AND PLANETARY LABORATORY) JOE GIACALONE (UA LPL) JARED ESPLEY (GSFC) AND JACOB GRUESBECK (GSFC).

$321,819FY2020National Aeronautics and Space AdministrationNASA

University Of Arizona, Tucson AZ

Investigators

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