An Overview of the Extratropical Storm Tracks in CMIP6 Historical Simulations

The representation of the winter and summer extratropical storm tracks in both hemispheres is evaluated in detail for the available models in phase 6 of the Coupled Model intercomparison Project (CMIP6). The state of the storm tracks from 1979 to 2014 is compared to that in ERA5 using a Lagrangian o...

Full description

Saved in:
Bibliographic Details
Published inJournal of climate Vol. 33; no. 15; pp. 6315 - 6343
Main Authors Priestley, Matthew D. K., Ackerley, Duncan, Catto, Jennifer L., Hodges, Kevin I., McDonald, Ruth E., Lee, Robert W.
Format Journal Article
LanguageEnglish
Published Boston American Meteorological Society 01.08.2020
Subjects
Algorithms
Bias
Climate change
Climate models
Cyclone tracks
Cyclones
Hemispheres
Intercomparison
Ocean basins
Ocean models
Physics
Precipitation
Resolution
Seasons
Storm tracks
Storms
Tracking
Europe
Online AccessGet full text

Cover

More Information
Summary:The representation of the winter and summer extratropical storm tracks in both hemispheres is evaluated in detail for the available models in phase 6 of the Coupled Model intercomparison Project (CMIP6). The state of the storm tracks from 1979 to 2014 is compared to that in ERA5 using a Lagrangian objective cyclone tracking algorithm. It is found that the main biases present in the previous generation of models (CMIP5) still persist, albeit to a lesser extent. The equatorward bias around the SH is much reduced and there appears to be some improvement in mean biases with the higher-resolution models, such as the zonal tilt of the North Atlantic storm track. Low-resolution models have a tendency to underestimate the frequency of high-intensity cyclones with all models simulating a peak intensity that is too low for cyclones in the SH. Explosively developing cyclones are underestimated across all ocean basins and in both hemispheres. In particular the models struggle to capture the rapid deepening required for these cyclones. For all measures, the CMIP6 models exhibit an overall improvement compared to the previous generation of CMIP5 models. In the NH most improvements can be attributed to increased horizontal resolution, whereas in the SH the impact of resolution is less apparent and any improvements are likely a result of improved model physics.
ISSN:0894-8755
1520-0442
DOI:10.1175/JCLI-D-19-0928.1