Vis enkel innførsel

dc.contributor.authorHall, Chris
dc.contributor.authorHolmen, Silje Eriksen
dc.contributor.authorMeek, Chris
dc.contributor.authorManson, Alan
dc.contributor.authorNozawa, Satonori
dc.date.accessioned2016-02-29T16:23:39Z
dc.date.available2016-02-29T16:23:39Z
dc.date.issued2016-02-26
dc.description.abstractThe turbopause is the demarcation between atmospheric mixing by turbulence (below) and molecular diffusion (above). When studying concentrations of trace species in the atmosphere, and particularly long-term change, it may be important to understand processes present, together with their temporal evolution that may be responsible for redistribution of atmospheric constituents. The general region of transition between turbulent and molecular mixing coincides with the base of the ionosphere, the lower region in which molecular oxygen is dissociated, and, at high latitude in summer, the coldest part of the whole atmosphere. This study updates previous reports of turbopause altitude, extending the time series by half a decade, and thus shedding new light on the nature of change over solar-cycle timescales. Assuming there is no trend in temperature, at 70◦ N there is evidence for a summer trend of ∼ 1.6 km decade−1 , but for winter and at 52◦ N there is no significant evidence for change at all. If the temperature at 90 km is estimated using meteor trail data, it is possible to estimate a cooling rate, which, if applied to the turbopause altitude estimation, fails to alter the trend significantly irrespective of season. The observed increase in turbopause height supports a hypothesis of corresponding negative trends in atomic oxygen density, [O]. This supports independent studies of atomic oxygen density, [O], using mid-latitude time series dating from 1975, which show negative trends since 2002.en_US
dc.identifier.citationAtmospheric Chemistry and Physics 2016, 16:2299-2308en_US
dc.identifier.cristinIDFRIDAID 1340582
dc.identifier.doi10.5194/acp-16-2299-2016
dc.identifier.issn1680-7324
dc.identifier.urihttps://hdl.handle.net/10037/8585
dc.identifier.urnURN:NBN:no-uit_munin_8207
dc.language.isoengen_US
dc.publisherEuropean Geosciences Union (EGU)en_US
dc.rights.accessRightsopenAccess
dc.subjectVDP::Matematikk og Naturvitenskap: 400::Geofag: 450en_US
dc.subjectVDP::Mathematics and natural science: 400::Geosciences: 450en_US
dc.titleChange in turbopause altitude at 52 and 70° Nen_US
dc.typeJournal articleen_US
dc.typeTidsskriftartikkelen_US
dc.typePeer revieweden_US


Tilhørende fil(er)

Thumbnail

Denne innførselen finnes i følgende samling(er)

Vis enkel innførsel