OBJECTIVE: THE OBJECTIVE OF THIS PROPOSAL IS TO STUDY TEMPERATURE VARIATIONS IN JUPITER S UPPER ATMOSPHERE IN ORDER TO DETERMINE THE MOST LIKELY SOURCE(S) OF HEATING. WE WILL CONDUCT A SERIES OF GROUND-BASED OBSERVATIONAL CAMPAIGNS OF JUPITER S IONOSPHERE AND IN PARTICULAR WE WILL FOCUS ON THE REGIONS SURROUNDING THE GREAT RED SPOT (GRS). THIS WORK WILL UNCOVER THE TEMPORAL AND SPATIAL VARIATIONS IN UPPER ATMOSPHERIC TEMPERATURES AT JUPITER AND WILL PROVIDE FIRM CONSTRAINTS ON THE DEGREE OF LOWER-TO-UPPER ATMOSPHERIC COUPLING. MOTIVATION: RECENT OBSERVATIONS FROM NASA S INFRARED TELESCOPE FACILITY (IRTF) HAVE LED TO THE DISCOVERY OF A LOCALIZED UPPER-ATMOSPHERIC HOTSPOT DIRECTLY ABOVE THE GRS. THIS HOTSPOT IS STRONG EVIDENCE FOR AN UNEXPECTED LOWER-TO-UPPER ATMOSPHERE COUPLING PROCESS AND FURTHER STUDY MAY PROVIDE A FIRM CONSTRAINT ON A NEW UPPER-ATMOSPHERIC HEAT SOURCE. AT PRESENT OBSERVATIONS OF UPPER-ATMOSPHERIC TEMPERATURES AT THE GIANT PLANETS ARE HUNDREDS OF KELVIN WARMER THAN CAN BE EXPLAINED BY MODELS THAT CONSIDER ONLY SOLAR HEATING. IN ORDER TO RESOLVE THIS MODEL-DATA DISCREPANCY TERMED A GIANT PLANET ENERGY CRISIS MODELERS HAVE EXAMINED A RANGE OF OTHER POSSIBLE HEAT SOURCES INCLUDING TRANSPORT OF AURORAL ENERGY EQUATORWARD AND WAVE HEATING FROM BELOW. THUS FAR HOWEVER NO ADDITIONAL HEAT SOURCE HAS BEEN ABLE TO ADEQUATELY EXPLAIN THE OBSERVED UPPER ATMOSPHERIC TEMPERATURES. THEREFORE THE DETECTION OF A HOTSPOT ABOVE THE GRS REPRESENTS EXCITING NEW EVIDENCE FOR AN UNEXPECTED COUPLING PROCESS AND MAY ULTIMATELY HELP TO RESOLVE THE ENERGY CRISIS AT JUPITER. METHODOLOGY: WE WILL PERFORM GROUND-BASED OBSERVATIONS OF JUPITER S MAJOR ION H3+ USING KECK AND IRTF. LINE RATIOS BETWEEN DIFFERENT H3+ SPECTRAL LINES CAN BE USED TO DERIVE THE COLUMN INTEGRATED TEMPERATURES AND DENSITIES OF THE EMITTING GAS. AS H3+ IS THERMALLY COUPLED TO THE NEUTRAL ATMOSPHERE IT THUS PROVIDES AN EXCELLENT MONITOR OF UPPER ATMOSPHERIC TEMPERATURES. THE IRTF CAMPAIGNS WILL FOCUS ON GLOBAL COVERAGE OVER LONG TIME PERIODS WHEREAS THE KECK CAMPAIGNS WILL BE TARGETED PRIMARILY NEAR THE GRS IN ORDER TO PROVIDE MORE PRECISE TEMPERATURE VARIATIONS AND HIGHER SPATIAL RESOLUTION. THEREFORE WE WILL HAVE THE GLOBAL CONTEXT OF UPPER ATMOSPHERIC TEMPERATURES AS WELL AS A MORE DETAILED UNDERSTANDING OF TRENDS NEAR THE GRS. THIS LATTER DATA SET WILL YIELD IMPORTANT CLUES REGARDING THE MECHANISMS BEHIND THE LOWER-TO-UPPER ATMOSPHERIC COUPLING AND LOCALIZED HEATING. IMPACT: THE CURRENT EVIDENCE FOR A GRS HOTSPOT IS BASED ON IRTF MEASUREMENTS FROM 2012 IN WHICH THE INSTRUMENT SLIT JUST SAMPLED THE GRS REGION BY CHANCE. THEREFORE A FOCUSED CAMPAIGN AS PROPOSED HERE WOULD HELP TO RESOLVE A NUMBER OF IMPORTANT QUESTIONS ABOUT THIS DISCOVERY INCLUDING: (1) HOW DO UPPER ATMOSPHERIC TEMPERATURES VARY WITH LATITUDE LONGITUDE AND TIME? (2) IF GRS ACTIVITY DRIVES AN UPPER ATMOSPHERIC HEATING PROCESS AS IMPLIED BY THE IRTF MEASUREMENTS WHAT OTHER STORM ACTIVITY AT OTHER LOCATIONS MIGHT ALSO HEAT THE UPPER ATMOSPHERE? HOW RELIABLY CAN THIS HEATING PROCESS BE EXTRAPOLATED TO OTHER GIANT PLANETS OR EXOPLANETS? (3) HOW DOES GRS ACTIVITY HEAT THE UPPER ATMOSPHERE? TO WHAT EXTENT DOES THIS LOCALIZED HEATING TRANSLATE TO GLOBAL HEATING? (4) IS THE DEGREE OF HEATING FROM THE GRS SUFFICIENT TO RESOLVE JUPITER S ENERGY CRISIS?