The process-oriented evaluation of Southern Ocean cloud and radiation errors in weather and climate models using cloud regimes
Cloud and shortwave radiation (SW) biases over the high-latitude Southern Ocean (SO) are persistent in many general circulation models (GCMs), and have been associated with large-scale circulation errors and uncertainties in cloud feedbacks in a warming climate. Physical processes below the grid-sca...
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ftmonashunivfig:oai:figshare.com:article/4697503 2023-05-15T18:24:47+02:00 The process-oriented evaluation of Southern Ocean cloud and radiation errors in weather and climate models using cloud regimes Mason, Shannon 2017-02-27T06:05:57Z https://doi.org/10.4225/03/58b3c1c71bf31 https://figshare.com/articles/thesis/The_process-oriented_evaluation_of_Southern_Ocean_cloud_and_radiation_errors_in_weather_and_climate_models_using_cloud_regimes/4697503 unknown doi:10.4225/03/58b3c1c71bf31 https://figshare.com/articles/thesis/The_process-oriented_evaluation_of_Southern_Ocean_cloud_and_radiation_errors_in_weather_and_climate_models_using_cloud_regimes/4697503 In Copyright monash:165920 ethesis-20160119-221238 thesis(doctorate) 2015 Open access Model evaluation Southern ocean 1959.1/1240493 Cloud Text Thesis 2017 ftmonashunivfig https://doi.org/10.4225/03/58b3c1c71bf31 2022-06-06T15:46:36Z Cloud and shortwave radiation (SW) biases over the high-latitude Southern Ocean (SO) are persistent in many general circulation models (GCMs), and have been associated with large-scale circulation errors and uncertainties in cloud feedbacks in a warming climate. Physical processes below the grid-scale of GCMs are represented by parameterisations; to prioritise improvements in model physics there is a need to identify which processes are the major contributors to model error. A promising approach to process-oriented model evaluation is to identify cloud regimes from passive satellite observations, the occurrence of which are functions of the large-scale weather state. The aims of this thesis are, first, to expand upon approaches to identifying cloud regimes and their associated weather states, and to more fully characterise the vertical structure and thermodynamic phase of cloud regimes in the Southern Ocean. We then apply this observational knowledge to model evaluation, so as to develop a cloud regime-oriented framework for identifying and quantifying cloud and radiation errors in GCMs, and their associations with processes represented by model physics. In this thesis we present significant and original contributions to the knowledge of SO cloud from observations, and to the use of cloud regimes to evaluate model errors. We identify robust distinctions between key midtopped cloud regimes that have been associated with errors in the SO, and develop a methodology for using active satellite observations to quantify the subgrid-scale variability of cloud structures within cloud regimes. We develop a novel approach to identifying hybrid cloud regimes from both observations and a GCM, and demonstrate applications to quantifying the effects of changes to model parameterisations. We use the hybrid cloud regime approach to compare the development of cloud and radiation errors between timescales by evaluating short-term weather hindcasts and long-term climate simulations of the same GCM. Key methodological contributions ... Thesis Southern Ocean Monash University: Figshare Southern Ocean |
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Open Polar |
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Monash University: Figshare |
op_collection_id |
ftmonashunivfig |
language |
unknown |
topic |
monash:165920 ethesis-20160119-221238 thesis(doctorate) 2015 Open access Model evaluation Southern ocean 1959.1/1240493 Cloud |
spellingShingle |
monash:165920 ethesis-20160119-221238 thesis(doctorate) 2015 Open access Model evaluation Southern ocean 1959.1/1240493 Cloud Mason, Shannon The process-oriented evaluation of Southern Ocean cloud and radiation errors in weather and climate models using cloud regimes |
topic_facet |
monash:165920 ethesis-20160119-221238 thesis(doctorate) 2015 Open access Model evaluation Southern ocean 1959.1/1240493 Cloud |
description |
Cloud and shortwave radiation (SW) biases over the high-latitude Southern Ocean (SO) are persistent in many general circulation models (GCMs), and have been associated with large-scale circulation errors and uncertainties in cloud feedbacks in a warming climate. Physical processes below the grid-scale of GCMs are represented by parameterisations; to prioritise improvements in model physics there is a need to identify which processes are the major contributors to model error. A promising approach to process-oriented model evaluation is to identify cloud regimes from passive satellite observations, the occurrence of which are functions of the large-scale weather state. The aims of this thesis are, first, to expand upon approaches to identifying cloud regimes and their associated weather states, and to more fully characterise the vertical structure and thermodynamic phase of cloud regimes in the Southern Ocean. We then apply this observational knowledge to model evaluation, so as to develop a cloud regime-oriented framework for identifying and quantifying cloud and radiation errors in GCMs, and their associations with processes represented by model physics. In this thesis we present significant and original contributions to the knowledge of SO cloud from observations, and to the use of cloud regimes to evaluate model errors. We identify robust distinctions between key midtopped cloud regimes that have been associated with errors in the SO, and develop a methodology for using active satellite observations to quantify the subgrid-scale variability of cloud structures within cloud regimes. We develop a novel approach to identifying hybrid cloud regimes from both observations and a GCM, and demonstrate applications to quantifying the effects of changes to model parameterisations. We use the hybrid cloud regime approach to compare the development of cloud and radiation errors between timescales by evaluating short-term weather hindcasts and long-term climate simulations of the same GCM. Key methodological contributions ... |
format |
Thesis |
author |
Mason, Shannon |
author_facet |
Mason, Shannon |
author_sort |
Mason, Shannon |
title |
The process-oriented evaluation of Southern Ocean cloud and radiation errors in weather and climate models using cloud regimes |
title_short |
The process-oriented evaluation of Southern Ocean cloud and radiation errors in weather and climate models using cloud regimes |
title_full |
The process-oriented evaluation of Southern Ocean cloud and radiation errors in weather and climate models using cloud regimes |
title_fullStr |
The process-oriented evaluation of Southern Ocean cloud and radiation errors in weather and climate models using cloud regimes |
title_full_unstemmed |
The process-oriented evaluation of Southern Ocean cloud and radiation errors in weather and climate models using cloud regimes |
title_sort |
process-oriented evaluation of southern ocean cloud and radiation errors in weather and climate models using cloud regimes |
publishDate |
2017 |
url |
https://doi.org/10.4225/03/58b3c1c71bf31 https://figshare.com/articles/thesis/The_process-oriented_evaluation_of_Southern_Ocean_cloud_and_radiation_errors_in_weather_and_climate_models_using_cloud_regimes/4697503 |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
doi:10.4225/03/58b3c1c71bf31 https://figshare.com/articles/thesis/The_process-oriented_evaluation_of_Southern_Ocean_cloud_and_radiation_errors_in_weather_and_climate_models_using_cloud_regimes/4697503 |
op_rights |
In Copyright |
op_doi |
https://doi.org/10.4225/03/58b3c1c71bf31 |
_version_ |
1766205671241416704 |