Southern Hemisphere Cloud–Dynamics Biases in CMIP5 Models and Their Implications for Climate Projections
This study quantifies cloud–radiative anomalies associated with interannual variability in the latitude of the Southern Hemisphere (SH) midlatitude eddy-driven jet, in 20 global climate models from phase 5 of the Coupled Model Intercomparison Project (CMIP5). Two distinct model types are found. In t...
Main Authors: | , |
---|---|
Format: | Text |
Language: | unknown |
Published: |
Columbia University
2014
|
Subjects: | |
Online Access: | https://dx.doi.org/10.7916/d84x57nw https://academiccommons.columbia.edu/doi/10.7916/D84X57NW |
id |
ftdatacite:10.7916/d84x57nw |
---|---|
record_format |
openpolar |
spelling |
ftdatacite:10.7916/d84x57nw 2023-05-15T18:25:46+02:00 Southern Hemisphere Cloud–Dynamics Biases in CMIP5 Models and Their Implications for Climate Projections Grise, Kevin M. Polvani, Lorenzo M. 2014 https://dx.doi.org/10.7916/d84x57nw https://academiccommons.columbia.edu/doi/10.7916/D84X57NW unknown Columbia University https://dx.doi.org/10.1175/jcli-d-14-00113.1 Cloud forecasting Clouds--Dynamics Climatic changes Air masses Clouds--Mathematical models Climatic changes--Forecasting Atmosphere Meteorology Text Articles article-journal ScholarlyArticle 2014 ftdatacite https://doi.org/10.7916/d84x57nw https://doi.org/10.1175/jcli-d-14-00113.1 2021-11-05T12:55:41Z This study quantifies cloud–radiative anomalies associated with interannual variability in the latitude of the Southern Hemisphere (SH) midlatitude eddy-driven jet, in 20 global climate models from phase 5 of the Coupled Model Intercomparison Project (CMIP5). Two distinct model types are found. In the first class of models (type I models), total cloud fraction is reduced at SH midlatitudes as the jet moves poleward, contributing to enhanced shortwave radiative warming. In the second class of models (type II models), this dynamically induced cloud radiative warming effect is largely absent. Type I and type II models have distinct deficiencies in their representation of observed Southern Ocean clouds, but comparison with two independent satellite datasets indicates that the cloud–dynamics behavior of type II models is more realistic. Because the SH midlatitude jet shifts poleward in response to CO₂ forcing, the cloud–dynamics biases uncovered from interannual variability are directly relevant for climate change projections. In CMIP5 model experiments with abruptly quadrupled atmospheric CO₂ concentrations, the global-mean surface temperature initially warms more in type I models, even though their equilibrium climate sensitivity is not significantly larger. In type I models, this larger initial warming is linked to the rapid adjustment of the circulation and clouds to CO₂ forcing in the SH, where a nearly instantaneous poleward shift of the midlatitude jet is accompanied by a reduction in the reflection of solar radiation by clouds. In type II models, the SH jet also shifts rapidly poleward with CO₂ quadrupling, but it is not accompanied by cloud radiative warming anomalies, resulting in a smaller initial global-mean surface temperature warming. Text Southern Ocean DataCite Metadata Store (German National Library of Science and Technology) Southern Ocean |
institution |
Open Polar |
collection |
DataCite Metadata Store (German National Library of Science and Technology) |
op_collection_id |
ftdatacite |
language |
unknown |
topic |
Cloud forecasting Clouds--Dynamics Climatic changes Air masses Clouds--Mathematical models Climatic changes--Forecasting Atmosphere Meteorology |
spellingShingle |
Cloud forecasting Clouds--Dynamics Climatic changes Air masses Clouds--Mathematical models Climatic changes--Forecasting Atmosphere Meteorology Grise, Kevin M. Polvani, Lorenzo M. Southern Hemisphere Cloud–Dynamics Biases in CMIP5 Models and Their Implications for Climate Projections |
topic_facet |
Cloud forecasting Clouds--Dynamics Climatic changes Air masses Clouds--Mathematical models Climatic changes--Forecasting Atmosphere Meteorology |
description |
This study quantifies cloud–radiative anomalies associated with interannual variability in the latitude of the Southern Hemisphere (SH) midlatitude eddy-driven jet, in 20 global climate models from phase 5 of the Coupled Model Intercomparison Project (CMIP5). Two distinct model types are found. In the first class of models (type I models), total cloud fraction is reduced at SH midlatitudes as the jet moves poleward, contributing to enhanced shortwave radiative warming. In the second class of models (type II models), this dynamically induced cloud radiative warming effect is largely absent. Type I and type II models have distinct deficiencies in their representation of observed Southern Ocean clouds, but comparison with two independent satellite datasets indicates that the cloud–dynamics behavior of type II models is more realistic. Because the SH midlatitude jet shifts poleward in response to CO₂ forcing, the cloud–dynamics biases uncovered from interannual variability are directly relevant for climate change projections. In CMIP5 model experiments with abruptly quadrupled atmospheric CO₂ concentrations, the global-mean surface temperature initially warms more in type I models, even though their equilibrium climate sensitivity is not significantly larger. In type I models, this larger initial warming is linked to the rapid adjustment of the circulation and clouds to CO₂ forcing in the SH, where a nearly instantaneous poleward shift of the midlatitude jet is accompanied by a reduction in the reflection of solar radiation by clouds. In type II models, the SH jet also shifts rapidly poleward with CO₂ quadrupling, but it is not accompanied by cloud radiative warming anomalies, resulting in a smaller initial global-mean surface temperature warming. |
format |
Text |
author |
Grise, Kevin M. Polvani, Lorenzo M. |
author_facet |
Grise, Kevin M. Polvani, Lorenzo M. |
author_sort |
Grise, Kevin M. |
title |
Southern Hemisphere Cloud–Dynamics Biases in CMIP5 Models and Their Implications for Climate Projections |
title_short |
Southern Hemisphere Cloud–Dynamics Biases in CMIP5 Models and Their Implications for Climate Projections |
title_full |
Southern Hemisphere Cloud–Dynamics Biases in CMIP5 Models and Their Implications for Climate Projections |
title_fullStr |
Southern Hemisphere Cloud–Dynamics Biases in CMIP5 Models and Their Implications for Climate Projections |
title_full_unstemmed |
Southern Hemisphere Cloud–Dynamics Biases in CMIP5 Models and Their Implications for Climate Projections |
title_sort |
southern hemisphere cloud–dynamics biases in cmip5 models and their implications for climate projections |
publisher |
Columbia University |
publishDate |
2014 |
url |
https://dx.doi.org/10.7916/d84x57nw https://academiccommons.columbia.edu/doi/10.7916/D84X57NW |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
https://dx.doi.org/10.1175/jcli-d-14-00113.1 |
op_doi |
https://doi.org/10.7916/d84x57nw https://doi.org/10.1175/jcli-d-14-00113.1 |
_version_ |
1766207412240384000 |