Title: New results on equatorial thermosphere dynamics from Brazil and Peru Abstract: Since the previous talk presented at Boston College in August 2012 on equatorial
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Title:NewresultsonequatorialthermospheredynamicsfromBrazilandPeru Abstract:SincetheprevioustalkpresentedatBostonCollegeinAugust2012onequatorial thermospheredynamics,newprogresshasbeenmaderegardingthemeasurementsof windsandtemperaturesintheSouthAmericanlongitudinalregion.Evidenceindicating thedevelopmentofnegativemeridionalwindgradientsduringtheeveninghasbeenfound forthenortheasternregionofBrazilbetweenthegeomagneticequatorandthesouthern Appletonanomaly.Theexistenceofthesegradientssupportstheideaofapossible mechanismthatmightunderliethedestabilizationoftheF‐regionplasmacausing scintillationandESFevents.Inaddition,aninterestingapproachtothestudyofthe equatorialthermosphereneutralwindfieldhasbeendevelopedthatisbaseduponanew methodofmappingtheneutralwindfield.ThisisastrategyinwhichtheDopplershiftsfor 8equi‐spacedazimuthalobservationsofthethermosphereneutralwindfieldareusedto determinetheparametersofamodelforthewindfieldmapfeaturingthefirstorder expansionoftheuandvcomponentsoftheneutralwindvectorintermsofthezonaland meridionalgradientsforbothuandvvectorcomponents.Resultsillustratesystematic changesinthevorticityanddivergenceofthewindfieldasafunctionoflocaltimethat occurasaresultoftheeveningday‐to‐nightpressuregradientandthesemi‐diurnaltidal wavestructurethatunderliesthepolewardpropagationofthemidnightpressurebulge throughthethermosphere.
