title: Dynamic processes governing lower-tropospheric HDO/H2O ratios as observed from space and ground.
abstract: The hydrological cycle and its response to environmental variability such as temperature changes is of prime importance for climate reconstruction and prediction. We retrieved deuterated water/water (HDO/H2O) abundances using spaceborne absorption spectroscopy, providing an almost global perspective on the near-surface distribution of water vapor isotopologs. We observed an unexpectedly high HDO/H2O seasonality in the inner Sahel region, pointing to a strong isotopic depletion in the subsiding branch of the Hadley circulation and its misrepresentation in general circulation models. An extension of the analysis at high latitudes using ground-based observations of deltaD and a model study shows that dynamic processes can entirely compensate for temperature effects on the isotopic composition of precipitation.
authors.affiliation: SRON-Netherlands Institute for Space Research, Sorbonnelaan 2, 3584CA Utrecht, Netherlands. C.Frankenberg@sron.nl
authors.forename: Christian
authors.initials: C
authors.lastname: Frankenberg
authors.forename: Kei
authors.initials: K
authors.lastname: Yoshimura
authors.forename: Thorsten
authors.initials: T
authors.lastname: Warneke
authors.forename: Ilse
authors.initials: I
authors.lastname: Aben
authors.forename: André
authors.initials: A
authors.lastname: Butz
authors.forename: Nicholas
authors.initials: N
authors.lastname: Deutscher
authors.forename: David
authors.initials: D
authors.lastname: Griffith
authors.forename: Frank
authors.initials: F
authors.lastname: Hase
authors.forename: Justus
authors.initials: J
authors.lastname: Notholt
authors.forename: Matthias
authors.initials: M
authors.lastname: Schneider
authors.forename: Hans
authors.initials: H
authors.lastname: Schrijver
authors.forename: Thomas
authors.initials: T
authors.lastname: Röckmann