@article{fdi:010061271,
  title = {{C}an we determine what controls the spatio-temporal distribution of d-excess and {O}-17-excess in precipitation using the {LMDZ} general circulation model ?},
  author = {{R}isi, {C}. and {L}andais, {A}. and {W}inkler, {R}. and {V}imeux, {F}ran{\c{c}}oise},
  editor = {},
  language = {{ENG}},
  abstract = {{C}ombined measurements of the ({H}2{O})-{O}-18 and {HDO} isotopic ratios in precipitation, leading to second-order parameter {D}-excess, have provided additional constraints on past climates compared to the ({H}2{O})-{O}-18 isotopic ratio alone. {M}ore recently, measurements of ({H}2{O})-{O}-17 have led to another second-order parameter: {O}-17-excess. {R}ecent studies suggest that {O}-17-excess in polar ice may provide information on evaporative conditions at the moisture source. {H}owever, the processes controlling the spatio-temporal distribution of {O}-17-excess are still far from being fully understood. {W}e use the isotopic general circulation model ({GCM}) {LMDZ} to better understand what controls d-excess and {O}-17-excess in precipitation at present-day ({PD}) and during the last glacial maximum ({LGM}). {T}he simulation of {D}-excess and {O}-17-excess is evaluated against measurements in meteoric water, water vapor and polar ice cores. {A} set of sensitivity tests and diagnostics are used to quantify the relative effects of evaporative conditions (sea surface temperature and relative humidity), {R}ayleigh distillation, mixing between vapors from different origins, precipitation re-evaporation and supersaturation during condensation at low temperature. {I}n {LMDZ}, simulations suggest that in the tropics convective processes and rain re-evaporation are important controls on precipitation {D}-excess and {O}-17-excess. {I}n higher latitudes, the effect of distillation, mixing between vapors from different origins and supersaturation are the most important controls. {F}or example, the lower {D}-excess and {O}-17-excess at {LGM} simulated at {LGM} are mainly due to the supersaturation effect. {T}he effect of supersaturation is however very sensitive to a parameter whose tuning would require more measurements and laboratory experiments. {E}vaporative conditions had previously been suggested to be key controlling factors of d-excess and {O}-17-excess, but {LMDZ} underestimates their role. {M}ore generally, some shortcomings in the simulation of {O}-17-excess by {LMDZ} suggest that general circulation models are not yet the perfect tool to quantify with confidence all processes controlling {O}-17-excess.},
  keywords = {},
  booktitle = {},
  journal = {{C}limate of the {P}ast},
  volume = {9},
  numero = {5},
  pages = {2173--2193},
  ISSN = {1814-9324},
  year = {2013},
  DOI = {10.5194/cp-9-2173-2013},
  URL = {https://www.documentation.ird.fr/hor/fdi:010061271},
}