---
_id: '9150'
abstract:
- lang: eng
text: The goal of this study is twofold. First, we aim at developing a simple model
as an interpretative framework for the water vapor isotopic variations in the
tropical troposphere over the ocean. We use large-eddy simulations to justify
the underlying assumptions of this simple model, to constrain its input parameters
and to evaluate its results. Second, we aim at interpreting the depletion of the
water vapor isotopic composition in the lower and mid-troposphere as precipitation
increases, which is a salient feature in tropical oceanic observations. This feature
constitutes a stringent test on the relevance of our interpretative framework.
Previous studies, based on observations or on models with parameterized convection,
have highlighted the roles of deep convective and meso-scale downdrafts, rain
evaporation, rain-vapor diffusive exchanges and mixing processes. The interpretative
framework that we develop is a two-column model representing the net ascent in
clouds and the net descent in the environment. We show that the mechanisms for
depleting the troposphere when precipitation rate increases all stem from the
higher tropospheric relative humidity. First, when the relative humidity is larger,
less snow sublimates before melting and a smaller fraction of rain evaporates.
Both effects lead to more depleted rain evaporation and eventually more depleted
water vapor. This mechanism dominates in regimes of large-scale ascent. Second,
the entrainment of dry air into clouds reduces the vertical isotopic gradient
and limits the depletion of tropospheric water vapor. This mechanism dominates
in regimes of large-scale descent.
article_processing_charge: No
author:
- first_name: Camille
full_name: Risi, Camille
last_name: Risi
- first_name: Caroline J
full_name: Muller, Caroline J
id: f978ccb0-3f7f-11eb-b193-b0e2bd13182b
last_name: Muller
orcid: 0000-0001-5836-5350
- first_name: Peter N.
full_name: Blossey, Peter N.
last_name: Blossey
citation:
ama: Risi C, Muller CJ, Blossey PN. Rain evaporation, snow melt and entrainment
at the heart of water vapor isotopic variations in the tropical troposphere, according
to large-eddy simulations and a two-column model. doi:10.1002/essoar.10504670.1
apa: Risi, C., Muller, C. J., & Blossey, P. N. (n.d.). Rain evaporation, snow
melt and entrainment at the heart of water vapor isotopic variations in the tropical
troposphere, according to large-eddy simulations and a two-column model. ESSOAr.
https://doi.org/10.1002/essoar.10504670.1
chicago: Risi, Camille, Caroline J Muller, and Peter N. Blossey. “Rain Evaporation,
Snow Melt and Entrainment at the Heart of Water Vapor Isotopic Variations in the
Tropical Troposphere, According to Large-Eddy Simulations and a Two-Column Model.”
ESSOAr, n.d. https://doi.org/10.1002/essoar.10504670.1.
ieee: C. Risi, C. J. Muller, and P. N. Blossey, “Rain evaporation, snow melt and
entrainment at the heart of water vapor isotopic variations in the tropical troposphere,
according to large-eddy simulations and a two-column model.” ESSOAr.
ista: Risi C, Muller CJ, Blossey PN. Rain evaporation, snow melt and entrainment
at the heart of water vapor isotopic variations in the tropical troposphere, according
to large-eddy simulations and a two-column model. 10.1002/essoar.10504670.1.
mla: Risi, Camille, et al. Rain Evaporation, Snow Melt and Entrainment at the
Heart of Water Vapor Isotopic Variations in the Tropical Troposphere, According
to Large-Eddy Simulations and a Two-Column Model. ESSOAr, doi:10.1002/essoar.10504670.1.
short: C. Risi, C.J. Muller, P.N. Blossey, (n.d.).
date_created: 2021-02-15T15:08:06Z
date_published: 2020-11-24T00:00:00Z
date_updated: 2022-01-24T12:32:10Z
day: '24'
doi: 10.1002/essoar.10504670.1
extern: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://doi.org/10.1002/essoar.10504670.1
month: '11'
oa: 1
oa_version: Preprint
publication_status: submitted
publisher: ESSOAr
status: public
title: Rain evaporation, snow melt and entrainment at the heart of water vapor isotopic
variations in the tropical troposphere, according to large-eddy simulations and
a two-column model
type: preprint
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
year: '2020'
...