The location of the thermodynamic atmosphere–ice interface in fully coupled models – a case study using JULES and CICE
In fully coupled climate models, it is now normal to include a sea ice component with multiple layers, each having their own temperature. When coupling this component to an atmosphere model, it is more common for surface variables to be calculated in the sea ice component of the model, the equivalen...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2016-03-01
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| Series: | Geoscientific Model Development |
| Online Access: | http://www.geosci-model-dev.net/9/1125/2016/gmd-9-1125-2016.pdf |
| _version_ | 1818845268085309440 |
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| author | A. E. West A. J. McLaren H. T. Hewitt M. J. Best |
| author_facet | A. E. West A. J. McLaren H. T. Hewitt M. J. Best |
| author_sort | A. E. West |
| collection | DOAJ |
| description | In fully coupled climate models, it is now normal to include a sea ice
component with multiple layers, each having their own temperature. When
coupling this component to an atmosphere model, it is more common for surface
variables to be calculated in the sea ice component of the model, the
equivalent of placing an interface immediately above the surface. This study
uses a one-dimensional (1-D) version of the Los Alamos sea ice model (CICE)
thermodynamic solver and the Met Office atmospheric surface exchange solver
(JULES) to compare this method with that of allowing the surface variables to
be calculated instead in the atmosphere, the equivalent of placing an
interface immediately below the surface.<br><br>
The model is forced with a sensible heat flux derived from a sinusoidally
varying near-surface air temperature. The two coupling methods are tested
first with a 1 h coupling frequency, and then a 3 h coupling frequency, both
commonly used. With an above-surface interface, the resulting surface
temperature and flux cycles contain large phase and amplitude errors, and have a very blocky shape. The simulation of both quantities is
greatly improved when the interface is instead placed within the top ice
layer, allowing surface variables to be calculated on the shorter timescale
of the atmosphere. There is also an unexpected slight improvement in the
simulation of the top-layer ice temperature by the ice model. The surface
flux improvement remains when a snow layer is added to the ice, and when the
wind speed is increased. The study concludes with a discussion of the
implications of these results to three-dimensional modelling. An appendix
examines the stability of the alternative method of coupling under various
physically realistic scenarios. |
| first_indexed | 2024-12-19T05:26:57Z |
| format | Article |
| id | doaj.art-b25ec49a79e74f6e9414500d4f17b6f8 |
| institution | Directory Open Access Journal |
| issn | 1991-959X 1991-9603 |
| language | English |
| last_indexed | 2024-12-19T05:26:57Z |
| publishDate | 2016-03-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Geoscientific Model Development |
| spelling | doaj.art-b25ec49a79e74f6e9414500d4f17b6f82022-12-21T20:34:22ZengCopernicus PublicationsGeoscientific Model Development1991-959X1991-96032016-03-01931125114110.5194/gmd-9-1125-2016The location of the thermodynamic atmosphere–ice interface in fully coupled models – a case study using JULES and CICEA. E. West0A. J. McLaren1H. T. Hewitt2M. J. Best3Met Office Hadley Centre, Exeter Devon, UKMet Office Hadley Centre, Exeter Devon, UKMet Office Hadley Centre, Exeter Devon, UKMet Office Hadley Centre, Exeter Devon, UKIn fully coupled climate models, it is now normal to include a sea ice component with multiple layers, each having their own temperature. When coupling this component to an atmosphere model, it is more common for surface variables to be calculated in the sea ice component of the model, the equivalent of placing an interface immediately above the surface. This study uses a one-dimensional (1-D) version of the Los Alamos sea ice model (CICE) thermodynamic solver and the Met Office atmospheric surface exchange solver (JULES) to compare this method with that of allowing the surface variables to be calculated instead in the atmosphere, the equivalent of placing an interface immediately below the surface.<br><br> The model is forced with a sensible heat flux derived from a sinusoidally varying near-surface air temperature. The two coupling methods are tested first with a 1 h coupling frequency, and then a 3 h coupling frequency, both commonly used. With an above-surface interface, the resulting surface temperature and flux cycles contain large phase and amplitude errors, and have a very blocky shape. The simulation of both quantities is greatly improved when the interface is instead placed within the top ice layer, allowing surface variables to be calculated on the shorter timescale of the atmosphere. There is also an unexpected slight improvement in the simulation of the top-layer ice temperature by the ice model. The surface flux improvement remains when a snow layer is added to the ice, and when the wind speed is increased. The study concludes with a discussion of the implications of these results to three-dimensional modelling. An appendix examines the stability of the alternative method of coupling under various physically realistic scenarios.http://www.geosci-model-dev.net/9/1125/2016/gmd-9-1125-2016.pdf |
| spellingShingle | A. E. West A. J. McLaren H. T. Hewitt M. J. Best The location of the thermodynamic atmosphere–ice interface in fully coupled models – a case study using JULES and CICE Geoscientific Model Development |
| title | The location of the thermodynamic atmosphere–ice interface in fully coupled models – a case study using JULES and CICE |
| title_full | The location of the thermodynamic atmosphere–ice interface in fully coupled models – a case study using JULES and CICE |
| title_fullStr | The location of the thermodynamic atmosphere–ice interface in fully coupled models – a case study using JULES and CICE |
| title_full_unstemmed | The location of the thermodynamic atmosphere–ice interface in fully coupled models – a case study using JULES and CICE |
| title_short | The location of the thermodynamic atmosphere–ice interface in fully coupled models – a case study using JULES and CICE |
| title_sort | location of the thermodynamic atmosphere ice interface in fully coupled models a case study using jules and cice |
| url | http://www.geosci-model-dev.net/9/1125/2016/gmd-9-1125-2016.pdf |
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