GFS.v16: update model/nh_utils.F90 with dz_min change

[junwang-noaa]

To resolve the model instability issue:
-The dz_min is changed from 2 to 6, and the order of computation is updated to run the code efficiently.

[yangfanglin]

looks good

[climbfuji]

@junwang-noaa are you planning to bring this back to dev/emc ? Are there any notes or an issue describing the problem? It sounds like it could be relevant for the GSL physics team, but I can't tell from the code changes alone. Thanks!

[yangfanglin]

Dom, GFS.v16 crashed a few times in early September when a strong typhoon passed through a small island over Japan. In the past month we have been working with GFDL to diagnose the causes. Different approaches have been tested to stabilize the model. It was found that a change made to model/nh_utils.F90 is the most effective and least intrusive. Its impact on forecast is small. The adjustments only occur rarely over a small portion of the grids. Fanglin

…

On Fri, Oct 2, 2020 at 12:57 PM Dom Heinzeller ***@***.***> wrote: @junwang-noaa <https://github.com/junwang-noaa> are you planning to bring this back to dev/emc ? Are there any notes or an issue describing the problem? It sounds like it could be relevant for the GSL physics team, but I can't tell from the code changes alone. Thanks! — You are receiving this because your review was requested. Reply to this email directly, view it on GitHub <#41 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AKY5N2KK462JKBFIQMLBBMLSIYBARANCNFSM4SB264DQ> .

-- *Fanglin Yang, Ph.D.* *Chief, Model Physics Group* *Modeling and Data Assimilation Branch* *NOAA/NWS/NCEP Environmental Modeling Center* *https://www.emc.ncep.noaa.gov/gmb/wx24fy/fyang/ <https://www.emc.ncep.noaa.gov/gmb/wx24fy/fyang/>*

[junwang-noaa]

Dom, yes we will bring back the code change to develop. Also the variable that was changed should be put in namelist to allow people to test in their own applications. I will open an issue. On Fri, Oct 2, 2020 at 1:06 PM Fanglin Yang <notifications@github.com> wrote:

…

Dom, GFS.v16 crashed a few times in early September when a strong typhoon passed through a small island over Japan. In the past month we have been working with GFDL to diagnose the causes. Different approaches have been tested to stabilize the model. It was found that a change made to model/nh_utils.F90 is the most effective and least intrusive. Its impact on forecast is small. The adjustments only occur rarely over a small portion of the grids. Fanglin On Fri, Oct 2, 2020 at 12:57 PM Dom Heinzeller ***@***.***> wrote: > @junwang-noaa <https://github.com/junwang-noaa> are you planning to bring > this back to dev/emc ? Are there any notes or an issue describing the > problem? It sounds like it could be relevant for the GSL physics team, but > I can't tell from the code changes alone. Thanks! > > — > You are receiving this because your review was requested. > Reply to this email directly, view it on GitHub > < #41 (comment) >, > or unsubscribe > < https://github.com/notifications/unsubscribe-auth/AKY5N2KK462JKBFIQMLBBMLSIYBARANCNFSM4SB264DQ > > . > -- *Fanglin Yang, Ph.D.* *Chief, Model Physics Group* *Modeling and Data Assimilation Branch* *NOAA/NWS/NCEP Environmental Modeling Center* *https://www.emc.ncep.noaa.gov/gmb/wx24fy/fyang/ <https://www.emc.ncep.noaa.gov/gmb/wx24fy/fyang/>* — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#41 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AI7D6TISWR4PJ7SKULDDKTLSIYB7ZANCNFSM4SB264DQ> .

[climbfuji]

Thanks, @yangfanglin and @junwang-noaa. This is useful to know.