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In the perturbation experiments it is possible to diagnose and also to modify temperature tendency contributions from the model physics (cloud, convection and radiation) in a specific region.
The temperature Temperature tendencies are produced through model dynamics and model physics:
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The contributions from the individual physical tendencies can be output in OpenIFS as an additional diagnostic using the PEXTRA output.
Note: The additional PEXTRA diagnostics have already been set up in this workshop's model experiment.
For reference and to learn how to enable this diagnostic output in OpenIFS please find the documentation here. On this page you will also find a pdf document with grid a Grib code table for the tendencies can be found.
Regional scaling of tendencies
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For this to succeed the size of the box and its movement direction and movement rate need to be defined. Note that the picture below is only an illustrative example for the box following the track of TC Karl and the shown box in the picture does not reflect the default values set in the model.
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The track coordinates of Tropical Cyclone Karl can be obtained for instance from your Metview macros or from the US National Hurricane Center: https://www.nhc.noaa.gov/data/tcr/AL122016_Karl.pdf |
Namelist control of the perturbation box domain
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&NAMLHBOX LBOXMODIFY_CLOUD=true, ! enable cloud scheme T tendency scaling LBOXMODIFY_CONV=true, ! enable convection T tendency scaling LBOXMODIFY_RAD=true, ! enable radiation T tendency scaling ZBOXTIMESTART=0., ! box start time in hours ZBOXTIMEEND=96., ! box end time in hours ZBOXLONWEST=295.7, ! box western longitude boundary in degrees ZBOXLONEAST=305.7, ! box eastern longitude boundary in degrees ZBOXLATSOUTH=28.8, ! box southern latitude boundary in degrees ZBOXLATNORTH=38.8, ! box northern latitude boundary in degrees ZBOXPRESSTOP=20000., ! box top level pressure in Pa (eg. 50000Pa) ZBOXPRESSBOT=90000., ! box bottom level pressure in Pa (eg. 90000Pa) ZBOXDLONBORDER=5., ! box longitude interpolation zone width in degrees ZBOXDLATBORDER=5., ! box latitude interpolation zone width in degrees ZBOXDPRSBORDER=5000., ! box pressure interpolation zone width in Pa ZBOXDLON=-0.667, ! change in box longitude in degrees/hour ZBOXDLAT=0.333, ! change in box latitude in degrees/hour ZBOXVALUE=1.0, ! value of the multiplyingscaling factor inside the box domain / |
Submitting perturbation experiments
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Changing the parameters defining the regional box domain is one recommended possible option.
We will then resubmit the h7cc control experiment to the batch scheduler with these changes applied.
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- Backup the results of your control run by renaming the output folder. Do this first to ensure you do not inadvertently overwrite your control experiment results.
- Discuss within your group which perturbation experiment experiments you would like want to carry out.
- Consider which likely results you expect to see from your perturbation perturbations (what are the key output parameters to check? what kind of plots would illustrate your likely findings?).
- If you intend to use the namlhbox domain you should first convince yourself that its geographical and vertical extent, its movement rate and direction, meet the needs of your experiment (does it really follow TC Karl? which parameters do you wish to scale? which scaling factor?).
- Apply the selected changes to your experiment and resubmit the model experiment.