A possibilistic interpretation of ensemble forecasts: experiments on the imperfect Lorenz 96 system

<p>Ensemble forecasting has gained popularity in the field of numerical medium-range weather prediction as a means of handling the limitations inherent to predicting the behaviour of high dimensional, nonlinear systems, that have high sensitivity to initial conditions. Through small strategica...

Full description

Bibliographic Details
Main Authors: N. Le Carrer, P. L. Green
Format: Article
Language:English
Published: Copernicus Publications 2020-06-01
Series:Advances in Science and Research
Online Access:https://www.adv-sci-res.net/17/39/2020/asr-17-39-2020.pdf
_version_ 1818863201698185216
author N. Le Carrer
P. L. Green
author_facet N. Le Carrer
P. L. Green
author_sort N. Le Carrer
collection DOAJ
description <p>Ensemble forecasting has gained popularity in the field of numerical medium-range weather prediction as a means of handling the limitations inherent to predicting the behaviour of high dimensional, nonlinear systems, that have high sensitivity to initial conditions. Through small strategical perturbations of the initial conditions, and in some cases, stochastic parameterization schemes of the atmosphere-ocean dynamical equations, ensemble forecasting allows one to sample possible future scenarii in a Monte-Carlo like approximation. Results are generally interpreted in a probabilistic way by building a predictive density function from the ensemble of weather forecasts. However, such a probabilistic interpretation is regularly criticized for not being reliable, because of the chaotic nature of the dynamics of the atmospheric system as well as the fact that the ensembles of forecasts are not, in reality, produced in a probabilistic manner. To address these limitations, we propose a novel approach: a possibilistic interpretation of ensemble predictions, taking inspiration from fuzzy and possibility theories. Our approach is tested on an imperfect version of the Lorenz 96 model and results are compared against those given by a standard probabilistic ensemble dressing. The possibilistic framework reproduces (ROC curve, resolution) or improves (ignorance, sharpness, reliability) the performance metrics of a standard univariate probabilistic framework. This work provides a first step to answer the question whether probability distributions are the right tool to interpret ensembles predictions.</p>
first_indexed 2024-12-19T10:12:00Z
format Article
id doaj.art-247f2378298a4a3dbb7b5958c786d63a
institution Directory Open Access Journal
issn 1992-0628
1992-0636
language English
last_indexed 2024-12-19T10:12:00Z
publishDate 2020-06-01
publisher Copernicus Publications
record_format Article
series Advances in Science and Research
spelling doaj.art-247f2378298a4a3dbb7b5958c786d63a2022-12-21T20:26:20ZengCopernicus PublicationsAdvances in Science and Research1992-06281992-06362020-06-0117394510.5194/asr-17-39-2020A possibilistic interpretation of ensemble forecasts: experiments on the imperfect Lorenz 96 systemN. Le CarrerP. L. Green<p>Ensemble forecasting has gained popularity in the field of numerical medium-range weather prediction as a means of handling the limitations inherent to predicting the behaviour of high dimensional, nonlinear systems, that have high sensitivity to initial conditions. Through small strategical perturbations of the initial conditions, and in some cases, stochastic parameterization schemes of the atmosphere-ocean dynamical equations, ensemble forecasting allows one to sample possible future scenarii in a Monte-Carlo like approximation. Results are generally interpreted in a probabilistic way by building a predictive density function from the ensemble of weather forecasts. However, such a probabilistic interpretation is regularly criticized for not being reliable, because of the chaotic nature of the dynamics of the atmospheric system as well as the fact that the ensembles of forecasts are not, in reality, produced in a probabilistic manner. To address these limitations, we propose a novel approach: a possibilistic interpretation of ensemble predictions, taking inspiration from fuzzy and possibility theories. Our approach is tested on an imperfect version of the Lorenz 96 model and results are compared against those given by a standard probabilistic ensemble dressing. The possibilistic framework reproduces (ROC curve, resolution) or improves (ignorance, sharpness, reliability) the performance metrics of a standard univariate probabilistic framework. This work provides a first step to answer the question whether probability distributions are the right tool to interpret ensembles predictions.</p>https://www.adv-sci-res.net/17/39/2020/asr-17-39-2020.pdf
spellingShingle N. Le Carrer
P. L. Green
A possibilistic interpretation of ensemble forecasts: experiments on the imperfect Lorenz 96 system
Advances in Science and Research
title A possibilistic interpretation of ensemble forecasts: experiments on the imperfect Lorenz 96 system
title_full A possibilistic interpretation of ensemble forecasts: experiments on the imperfect Lorenz 96 system
title_fullStr A possibilistic interpretation of ensemble forecasts: experiments on the imperfect Lorenz 96 system
title_full_unstemmed A possibilistic interpretation of ensemble forecasts: experiments on the imperfect Lorenz 96 system
title_short A possibilistic interpretation of ensemble forecasts: experiments on the imperfect Lorenz 96 system
title_sort possibilistic interpretation of ensemble forecasts experiments on the imperfect lorenz 96 system
url https://www.adv-sci-res.net/17/39/2020/asr-17-39-2020.pdf
work_keys_str_mv AT nlecarrer apossibilisticinterpretationofensembleforecastsexperimentsontheimperfectlorenz96system
AT plgreen apossibilisticinterpretationofensembleforecastsexperimentsontheimperfectlorenz96system
AT nlecarrer possibilisticinterpretationofensembleforecastsexperimentsontheimperfectlorenz96system
AT plgreen possibilisticinterpretationofensembleforecastsexperimentsontheimperfectlorenz96system