Nonstationary stochastic rain type generation: accounting for climate drivers

<p>At subdaily resolution, rain intensity exhibits a strong variability in space and time, which is favorably modeled using stochastic approaches. This strong variability is further enhanced because of the diversity of processes that produce rain (e.g., frontal storms, mesoscale convective sys...

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Main Authors: L. Benoit, M. Vrac, G. Mariethoz
Format: Article
Language:English
Published: Copernicus Publications 2020-05-01
Series:Hydrology and Earth System Sciences
Online Access:https://www.hydrol-earth-syst-sci.net/24/2841/2020/hess-24-2841-2020.pdf
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author L. Benoit
M. Vrac
G. Mariethoz
author_facet L. Benoit
M. Vrac
G. Mariethoz
author_sort L. Benoit
collection DOAJ
description <p>At subdaily resolution, rain intensity exhibits a strong variability in space and time, which is favorably modeled using stochastic approaches. This strong variability is further enhanced because of the diversity of processes that produce rain (e.g., frontal storms, mesoscale convective systems and local convection), which results in a multiplicity of space–time patterns embedded into rain fields and in turn leads to the nonstationarity of rain statistics. To account for this nonstationarity in the context of stochastic weather generators and therefore preserve the relationships between rainfall properties and climatic drivers, we propose to resort to rain type simulation.</p> <p>In this paper, we develop a new approach based on multiple-point statistics to simulate rain type time series conditional to meteorological covariates. The rain type simulation method is tested by a cross-validation procedure using a 17-year-long rain type time series defined over central Germany. Evaluation results indicate that the proposed approach successfully captures the relationships between rain types and meteorological covariates. This leads to a proper simulation of rain type occurrence, persistence and transitions. After validation, the proposed approach is applied to generate rain type time series conditional to meteorological covariates simulated by a regional climate model under an RCP8.5 (Representative Concentration Pathway) emission scenario. Results indicate that, by the end of the century, the distribution of rain types could be modified over the area of interest, with an increased frequency of convective- and frontal-like rains at the expense of more stratiform events.</p>
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spelling doaj.art-9725d6ed9bfb474db84133f3364de96e2022-12-21T23:57:40ZengCopernicus PublicationsHydrology and Earth System Sciences1027-56061607-79382020-05-01242841285410.5194/hess-24-2841-2020Nonstationary stochastic rain type generation: accounting for climate driversL. Benoit0M. Vrac1G. Mariethoz2Institute of Earth Surface Dynamics (IDYST), University of Lausanne, Lausanne, SwitzerlandLaboratory for Sciences of Climate and Environment (LSCE-IPSL), CNRS/CEA/UVSQ, Orme des Merisiers, FranceInstitute of Earth Surface Dynamics (IDYST), University of Lausanne, Lausanne, Switzerland<p>At subdaily resolution, rain intensity exhibits a strong variability in space and time, which is favorably modeled using stochastic approaches. This strong variability is further enhanced because of the diversity of processes that produce rain (e.g., frontal storms, mesoscale convective systems and local convection), which results in a multiplicity of space–time patterns embedded into rain fields and in turn leads to the nonstationarity of rain statistics. To account for this nonstationarity in the context of stochastic weather generators and therefore preserve the relationships between rainfall properties and climatic drivers, we propose to resort to rain type simulation.</p> <p>In this paper, we develop a new approach based on multiple-point statistics to simulate rain type time series conditional to meteorological covariates. The rain type simulation method is tested by a cross-validation procedure using a 17-year-long rain type time series defined over central Germany. Evaluation results indicate that the proposed approach successfully captures the relationships between rain types and meteorological covariates. This leads to a proper simulation of rain type occurrence, persistence and transitions. After validation, the proposed approach is applied to generate rain type time series conditional to meteorological covariates simulated by a regional climate model under an RCP8.5 (Representative Concentration Pathway) emission scenario. Results indicate that, by the end of the century, the distribution of rain types could be modified over the area of interest, with an increased frequency of convective- and frontal-like rains at the expense of more stratiform events.</p>https://www.hydrol-earth-syst-sci.net/24/2841/2020/hess-24-2841-2020.pdf
spellingShingle L. Benoit
M. Vrac
G. Mariethoz
Nonstationary stochastic rain type generation: accounting for climate drivers
Hydrology and Earth System Sciences
title Nonstationary stochastic rain type generation: accounting for climate drivers
title_full Nonstationary stochastic rain type generation: accounting for climate drivers
title_fullStr Nonstationary stochastic rain type generation: accounting for climate drivers
title_full_unstemmed Nonstationary stochastic rain type generation: accounting for climate drivers
title_short Nonstationary stochastic rain type generation: accounting for climate drivers
title_sort nonstationary stochastic rain type generation accounting for climate drivers
url https://www.hydrol-earth-syst-sci.net/24/2841/2020/hess-24-2841-2020.pdf
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