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| Titel |
Submillimeter wave instrument on the Japanese Mars orbiter MELOS-1 |
| VerfasserIn |
Takeshi Kuroda, Yasuko Kasai, Hideo Sagawa, Paul Hartogh, Takeshi Manabe, Donal Murtagh |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250037297
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| Zusammenfassung |
| The Submillimeter wave (SMM) instrument is proposed for the Japanese Mars orbiter
(MELOS-1) which launch is planned in 2018. Characteristics of the SMM instrument are the
observations of wind, temperature, CO, water vapor and its isotopes, and minor radical species
such as O_3,H2O_2andHO2. Many potential contributions to the Martian science are expected
from these measurements: for example, the understanding of the Martian atmospheric
circulation regime, the water cycle and variable hygropause, isotopic fractionation including
HDO/H_2O,photochemistryinthemiddleatmosphere,andthermophysicalpropertiesofthesurfacelayer.
Theobservingstrategyistocombinebothlimbandnadirobservationsfromtheellipticorbit.Inthelimbobservingmode,severaltangentialheightsarepointedbyusingthespacecraftmaneuver,whichimprovestheverticalresolutionofwindandtemperatureobservations.Thenadirobservingmodehasanadvantageofconductinghorizontalmappingwithtemporalvariationofminormolecules.Sincethedustandicecloudarealmosttransparentatsubmillimeterwavelengths,theSMMinstrumentcanprovideobservationaldatawithoutbeingaffectedbydustdistributions.
Thedraftdesignoftheinstrumentishavingdualfrequencyreceiversof500and600or800GHzinordertoobserveatleasttwowatervaporlines,includingthegroundstate110˘101transitionat556.9GHz,withdifferentlinestrengths.CombinationoftheobservationsofweakandstrongopacitylinesenablesustomeasuretheH2O
abundance in a wide altitude range: from the surface to higher than 100 km.
This study will optimize the instrumental design by examining its scientific performance with
the observation simulations. We also discuss the scientific significances of the planned
observations in collaboration with the studies using general circulation models (GCMs) for
the Martian atmosphere. |
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