@article{PAR00003038,
  title = {{I}nfluence of convective processes on the isotopic composition (delta {O}-18 and delta {D}) of precipitation and water vapor in the tropics : 2. {P}hysical interpretation of the amount effect - art. no. {D}19306},
  author = {{R}isi, {C}. and {B}ony, {S}. and {V}imeux, {F}ran{\c{c}}oise},
  editor = {},
  language = {{ENG}},
  abstract = {{I}n the tropics, the proportion of heavier water isotopes in precipitation is anticorrelated with the precipitation amount. {T}he physical processes underlying this so-called amount effect are still poorly understood and quantified. {I}n the present study, stable water isotopes (({H}2{O})-{O}-18 and {HDO}) have been introduced in a single column model including the {E}manuel convection parameterization. {W}e investigate the physical processes underlying the amount effect and propose a methodology to quantify their relative contributions. {W}e focus on convective processes, since the idealized framework of the single column models does not allow us to consider the effects of large-scale horizontal advections of air masses of different isotopic signatures. {W}e show that two kinds of processes predominantly explain the amount effect: first, the reevaporation of the falling rain and the diffusive exchanges with the surrounding vapor; and second, the recycling of the subcloud layer vapor feeding the convective system by convective fluxes. {T}his highlights the importance of a detailed representation of rain evaporation processes to simulate accurately the isotopic composition of precipitation in the tropics. {T}he variability of the isotopic composition on different timescales ( from days to months) is also studied using a unidimensional simulation of the {T}ropical {O}cean - {G}lobal {A}tmosphere - {C}oupled {O}cean-{A}tmosphere {R}esponse {E}xperiment ({TOGA}-{COARE}) campaign. {T}he amount effect is best observable at intraseasonal or longer timescales. {T}he period of time over which convective activity significantly affects the isotopic composition of precipitation is related to the residence time of water within atmospheric reservoirs.},
  keywords = {},
  booktitle = {},
  journal = {{J}ournal of {G}eophysical {R}esearch - {A}tmospheres},
  volume = {113},
  numero = {{D}19},
  pages = {},
  ISSN = {0148-0227},
  year = {2008},
  DOI = {10.1029/2008jd009943},
  URL = {https://www.documentation.ird.fr/hor/{PAR}00003038},
}