Hi Miguel. Thanks for quick response and the enlightenment. We are looking at multiple layers and some other workarounds. For certain members of the network involved with similar but not identical configurations we are getting good results in any case. I am sure we can get this to work more than acceptably.
Again, many thanks. S. Bryn Jones Content Development Meteorologist Content Division Pelmorex - The Weather Network Tel.: (905) 829-1159 ext.1401 [email protected]<mailto:[email protected]> ________________________________ From: Miguel Tremblay [mailto:[email protected]] Sent: Thursday, March 03, 2011 9:19 AM To: Bryn Jones Cc: [email protected] Subject: Re: [Metro-developers] Allowable thickness for concrete (cement) On 03/02/2011 09:24 PM, Bryn Jones wrote: Greetings. I was wondering what the limits are, if any, for the thickness of concrete road beds in METRo. We were using a value of 0.3018 m which worked but a shallower 0.3017 m did not work and METRo choked. Somewhere in between there seems to be an allowable threshold. Is this correct? If so, ~1 foot of concrete as a minimum seems awfully thick. Do any of the other road bed materials (sand, asphalt and crushed rock) have maximum and/or minimum allowable thicknesses? Thanks. S. Bryn Jones Content Development Meteorologist Content Division Pelmorex - The Weather Network Tel.: (905) 829-1159 ext.1401 [email protected]<mailto:[email protected]> Hi Bryn, If you look at the documentation for the station configuration file (http://documentation.wikia.com/wiki/Input_station_%28METRo%29), you will find the following paragraph: Warning: Under particular condition, METRo will not be able to run with a given configuration. You will then see an error containing the string "Numerical stability test failed". See the first bullet of the changelog of version 3.0.1<http://documentation.wikia.com/wiki/Changelog_%28METRo%29#Changes_7> for more information. The first bullet is : * Stability check for the CFL condition<http://en.wikipedia.org/wiki/Courant%E2%80%93Friedrichs%E2%80%93Lewy_condition> in file grille.f. See https://gna.org/bugs/?7737 The CFL condition is well know in the Numerical Weather Prediction world. In METRo, this condition implies that, for numerical stability reasons, a given layer can not be less than a certain thickness. The thickness depends of the layer's type. In the next METRo version, to be released this summer, you will be able to define you own layer types. Thus, you will be able to fine tune the station configuration by using the physical parameters (conductivity and capacity) of your layer. But before that, you will have to play with the layer thickness. Using another type might also works and gives better results. Hope this answers your question, Miguel -- Miguel Tremblay Coordonnateur national des services commerciaux de données- National coordinator, commercial data services Centre météorologique canadien - Canadian meteorological centre (CMC) Environnement Canada - Environment Canada http://www.ec.gc.ca/ 2121 Trans-Canada N. Suite 230 Téléphone/Phone: 514-421-4729 Dorval, Québec Fax: 514-421-4679 CANADA H9P 1J3 courriel/email: [email protected]<mailto:[email protected]>
_______________________________________________ METRo-developers mailing list [email protected] https://mail.gna.org/listinfo/metro-developers
