++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ From greve at lowtem.hokudai.ac.jp Tue Oct 23 05:03:55 2018 From: greve at lowtem.hokudai.ac.jp (Ralf Greve) Date: Tue, 23 Oct 2018 06:03:55 +0300 Subject: [SICOPOLIS:63] Boundary conditions for SIA-SStA hybrid solver In-Reply-To: References: Message-ID: <7016914e-3427-6d80-a115-1b466c6b9236@lowtem.hokudai.ac.jp> Dear colleagues, a while ago, I realized that there is a problem with the boundary conditions at grounded ice fronts for the shallow-ice--shelfy-stream (SIA-SStA) hybrid solver in SICOPOLIS: While calving fronts of floating ice have a proper ocean-pressure boundary condition, no particular boundary condition was applied for grounded ice fronts. In the revisions 1347, 1348 and 1350, I have fixed this. The SIA part of the solution is unaffected, but for the SStA part, there are now proper stress boundary conditions for both land- and marine-terminating grounded ice fronts. For land-terminating fronts, the stress is assumed to be zero (atmospheric pressure neglected as usual), and for marine-terminating fronts, the stress results from the ocean pressure in the same way as for calving fronts of floating ice. For a quick look at the commit logs, see . Best regards, Ralf -- Dr. Ralf Greve Professor, Glacier and Ice Sheet Research Institute of Low Temperature Science Hokkaido University Kita-19, Nishi-8, Kita-ku Sapporo 060-0819, Japan Phone: (+81)-(0)11-706-6891 greve at lowtem.hokudai.ac.jp http://wwwice.lowtem.hokudai.ac.jp/~greve/ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ From greve at lowtem.hokudai.ac.jp Tue Oct 23 07:13:39 2018 From: greve at lowtem.hokudai.ac.jp (Ralf Greve) Date: Tue, 23 Oct 2018 08:13:39 +0300 Subject: [SICOPOLIS:64] Basal sliding with reduced basal pressure In-Reply-To: References: Message-ID: <1db4d94a-1540-f2b6-2837-32d282bcc395@lowtem.hokudai.ac.jp> Dear colleagues, for the basal sliding law with reduced basal pressure (overburden ice pressure minus basal water pressure, option SLIDE_LAW=2), a limiter RED_PRES_LIMIT_FACT is applied to the reduced basal pressure to avoid a singularity in the SIA solution. This limiter is also applied to the SStA solution, even though it is not needed there. In the revisions 1351, 1352 and 1356 (-> commit logs ), I have implemented a new option SLIDE_LAW=3. In this option, the limiter RED_PRES_LIMIT_FACT is used only for the SIA solution, but not for the SStA solution any more. This allows the reduced basal pressure going to zero as one approaches the grounding line, thus producing a very smooth transition between grounded and floating ice when the SIA-SStA hybrid solver is used. Best regards, Ralf -- Dr. Ralf Greve Professor, Glacier and Ice Sheet Research Institute of Low Temperature Science Hokkaido University Kita-19, Nishi-8, Kita-ku Sapporo 060-0819, Japan Phone: (+81)-(0)11-706-6891 greve at lowtem.hokudai.ac.jp http://wwwice.lowtem.hokudai.ac.jp/~greve/ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ From greve at lowtem.hokudai.ac.jp Wed Oct 31 09:34:29 2018 From: greve at lowtem.hokudai.ac.jp (Ralf Greve) Date: Wed, 31 Oct 2018 17:34:29 +0900 Subject: [SICOPOLIS:65] Important comment on revision 1368 Message-ID: <88bf65b7-8473-cf08-81d4-70e3bd6b5de7@lowtem.hokudai.ac.jp> Dear colleagues, the revision I just committed (1368) involves some crucial changes in the script sico.sh. In order not to cause conflicts with any modifications of sico.sh you might have made, an `svn update` will only update the template of sico.sh in sicopolis/runs/templates, but not the main version in sicopolis/runs. If you have not made any changes in sico.sh, you can simply copy the version from sicopolis/runs/templates to sicopolis/runs. However, if you have made any changes in sico.sh, please merge in the changes of revision 1368. You will find a diff between the previous and the new version here: . If there are any problems with the new revision, please contact . Thanks! Best regards, Ralf -- Dr. Ralf Greve Professor, Glacier and Ice Sheet Research Institute of Low Temperature Science Hokkaido University Kita-19, Nishi-8, Kita-ku Sapporo 060-0819, Japan Phone: (+81)-(0)11-706-6891 greve at lowtem.hokudai.ac.jp http://wwwice.lowtem.hokudai.ac.jp/~greve/ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ From greve at lowtem.hokudai.ac.jp Wed Oct 31 10:13:40 2018 From: greve at lowtem.hokudai.ac.jp (Ralf Greve) Date: Wed, 31 Oct 2018 18:13:40 +0900 Subject: [SICOPOLIS:66] Discontinue support for GNU Autotools? Message-ID: <6eaca298-8663-bdee-942f-79ee5e9e9276@lowtem.hokudai.ac.jp> Dear colleagues, by the way, following up on my previous mail: Revision 1368 does not work with the GNU Autotools yet! On that occasion, I'd like to ask whether somebody still uses SICOPOLIS with the GNU Autotools. Personally, I find it a bit over the top. Manual configuration with the sico_configs.sh script reflects the low-tech philosophy of SICOPOLIS better and, at least in my experience, it works very well. Therefore, I am inclined to discontinue the support for the Autotools in SICOPOLIS. If you disagree, please protest! For that case, I will change my mind and keep the Autotools option. However, if I do not get any mails in favour of keeping it, I will give it up in a future release. Thanks & best regards, Ralf -- Dr. Ralf Greve Professor, Glacier and Ice Sheet Research Institute of Low Temperature Science Hokkaido University Kita-19, Nishi-8, Kita-ku Sapporo 060-0819, Japan Phone: (+81)-(0)11-706-6891 greve at lowtem.hokudai.ac.jp http://wwwice.lowtem.hokudai.ac.jp/~greve/ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++