From Claire.Yung at anu.edu.au Mon Nov 4 17:17:37 2024 From: Claire.Yung at anu.edu.au (Claire Yung) Date: Mon, 4 Nov 2024 22:17:37 +0000 Subject: [MITgcm-support] Spurious behaviour beneath ice shelves with advection scheme 33 Message-ID: ?Hi MITgcm users, Apologies if this issue has already been noted. In idealised MITgcm ice shelf cavity model tests we?ve found some strange looking temperature-salinity space profiles that suggest anomalously fresh water (not following the expected ice shelf water mass transformation), mostly occurring in the grid cells immediately below ice. This problem occurred with the 3rd order DST flux limited advection scheme 33: staggerTimeStep=.TRUE., tempAdvScheme=33, saltAdvScheme=33, The issue was resolved by using the 2nd order flux limiter advection scheme 77 instead (thanks Paul Holland for the suggestion and Tore Hattermann for uncovering the problem). Just wanted to flag this issue for other/future MITgcm ice shelf users! Though, if anyone has looked into why this happens I?d be keen to hear. Thanks Claire ~~~ Claire Yung [she/her] PhD student Research School of Earth Sciences The Australian National University Canberra ACT 2600 -------------- next part -------------- An HTML attachment was scrubbed... URL: From hengling_leng at hotmail.com Tue Nov 5 05:55:55 2024 From: hengling_leng at hotmail.com (Leng Hengling) Date: Tue, 5 Nov 2024 10:55:55 +0000 Subject: [MITgcm-support] Restoring sea ice using RBCS and SEAICE Message-ID: Hi all, I know that the RBCS pkg can be used to restore water temperature, salinity, velocity, and tracers - essentially using a nudging method. Is it possible to extend RBCS to restore sea ice concentration, thickness, and drift speed with the SEAICE pkg? I plan to work on this issue and would greatly appreciate any suggestions you might have. Thank you! Best regards, Hengling Leng -------------- next part -------------- An HTML attachment was scrubbed... URL: From Martin.Losch at awi.de Tue Nov 5 06:12:48 2024 From: Martin.Losch at awi.de (Martin Losch) Date: Tue, 5 Nov 2024 12:12:48 +0100 Subject: [MITgcm-support] Restoring sea ice using RBCS and SEAICE In-Reply-To: References: Message-ID: Should be possible, but for ice velocities it does not make too much sense, because they have very little memory, i.e. if you modify them somewhere along the timestep, they will be recomputed very similarly in the next timestep, because the acceleration term du/dt is small. Martin > On 5. Nov 2024, at 11:55, Leng Hengling wrote: > > Hi all, > > I know that the RBCS pkg can be used to restore water temperature, salinity, velocity, and tracers - essentially using a nudging method. Is it possible to extend RBCS to restore sea ice concentration, thickness, and drift speed with the SEAICE pkg? I plan to work on this issue and would greatly appreciate any suggestions you might have. Thank you! > > Best regards, > > Hengling Leng > _______________________________________________ > MITgcm-support mailing list > MITgcm-support at mitgcm.org > http://mailman.mitgcm.org/mailman/listinfo/mitgcm-support -------------- next part -------------- An HTML attachment was scrubbed... URL: