Linked Life Data

11538474

Source:http://linkedlifedata.com/resource/pubmed/id/11538474

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1996-5-17
pubmed:abstractText
Mass fractionation by hydrodynamic hydrogen escape is a promising mechanism for explaining the observed elemental and isotopic abundance patterns in terrestrial planet atmospheres. Previous work has considered only pure hydrogen winds. Here, the theory of mass fractionation by hydrogen escape is extended to atmospheres in which hydrogen is not the only major constituent. Analytical solutions are derived for cases in which all relevant atmospheric constituents escape; both analytical and numerical solutions are obtained for cases in which important heavy constituents are retained. In either case the fractionation patterns that result can differ significantly from those produced by pure hydrogen winds. Three applications of the theory are discussed: (1) The observed fractionation of terrestrial atmospheric neon with respect to mantle neon can be explained as a by-product of diffusion-limited hydrogen escape from a steam atmosphere toward the end of accretion. (2) The anomalously high Martian (SNC) 38Ar/36Ar ratio is attributed to hydrodynamic fractionation by a vigorously escaping, nearly pure hydrogen wind. (3) It is possible that the present high Martian D/H ratio was established during the same hydrodynamic escape phase that fractionated argon, but the predicted degree of D/H enrichment is sensitive to other, less well constrained parameters.
pubmed:keyword
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
S
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0019-1035
pubmed:author
pubmed:issnType
Print
pubmed:volume
84
pubmed:owner
NASA
pubmed:authorsComplete
Y
pubmed:pagination
502-27
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Mass fractionation of noble gases in diffusion-limited hydrodynamic hydrogen escape.
pubmed:affiliation
NASA Ames Research Center, Moffett Field, California 94035, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't