loading page

The influence of convective aggregation on the stable isotopic composition of water vapor: Implications for the humidity of the troposphere
  • +5
  • Joseph Galewsky,
  • Matthias Schneider,
  • Christopher Johannes Diekmann,
  • Addisu Gezahegn Semie,
  • Sandrine Bony,
  • Camille Risi,
  • Kerry A. Emanuel,
  • Hélène Brogniez
Joseph Galewsky
University of New Mexico

Corresponding Author:[email protected]

Author Profile
Matthias Schneider
Karlsruhe Institute of Technology
Author Profile
Christopher Johannes Diekmann
Telespazio Germany GmbH
Author Profile
Addisu Gezahegn Semie
Laboratoire de Meteorologie Dynamique (LMD), CNRS/UPMC
Author Profile
Sandrine Bony
CNRS France
Author Profile
Camille Risi
Laboratoire de Météorologie Dynamique
Author Profile
Kerry A. Emanuel
Massachusetts Institute of Technology
Author Profile
Hélène Brogniez
Laboratoire atmosphères, observations spatiales
Author Profile


Remote sensing datasets of water vapor isotopic composition are used along with objective measures of convective aggregation to better understand the impact of convective aggregation on the atmospheric hydrologic cycle in the global tropics ($30^{\circ}$N to $30^{\circ}$S) for the period 2015-2020. When convection is unaggregated, vertical velocity profiles are top-heavy, mixing ratios increase and water vapor $\delta D$ decreases as the mean precipitation rate increases, consistent with partial hydrometeor evaporation below anvils into a relatively humid atmospheric column. Aggregated convection is associated with bottom-heavy vertical velocity profiles and a positive correlation between mixing ratio and $\delta D$, a result that is consistent with isotopic enrichment from detrainment of shallow convection near the observation level. Intermediate degrees of aggregation do not display significant variation in $\delta D$ with mixing ratio or precipitation rate. Convective aggregation provides a useful paradigm for understanding the relationships between mixing ratio and isotopic composition across a range of convective settings. The results presented here may have utility for a variety of applications including the interpretation of paleoclimate archives and the evaluation of numerical simulations of convection.
13 Jan 2023Submitted to ESS Open Archive
16 Jan 2023Published in ESS Open Archive