Velocity is too large near open boundary

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hezhi
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Joined: Wed Apr 11, 2018 2:31 pm
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Velocity is too large near open boundary

#1 Post by hezhi »

ROMS Users:
I find the velocity is too large near open boundary, but it don't blow up。I try to change .h file,but it does not work。What can I do for next step?
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roms_Indian_Ocean.in
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indian_ocean.h
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kate
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Re: Velocity is too large near open boundary

#2 Post by kate »

You haven't told us anything about your boundary conditions except which options you have. What is the frequency of providing new information and what is the source of it? I remember seeing a vast improvement when going from monthly climatology of just T and S to 5-daily SODA fields. The climatology is a collection of whatever measurements they have for a given season/location, not at all consistent with each other, while the SODA fields are internally consistent views of T, S and velocity, also SSH. Daily is better than monthly, if you can get it.

hezhi
Posts: 10
Joined: Wed Apr 11, 2018 2:31 pm
Location: FIO

Re: Velocity is too large near open boundary

#3 Post by hezhi »

Dear Kate
the frequency of boundary fields are monthly,which is from monthly data of ORAS4. ERA5 data is source of my force fields. The data don't belong to climatology。
Last edited by hezhi on Wed Dec 23, 2020 6:25 am, edited 1 time in total.

hezhi
Posts: 10
Joined: Wed Apr 11, 2018 2:31 pm
Location: FIO

Re: Velocity is too large near open boundary

#4 Post by hezhi »

Could you recommend some kinds of data are better for running a long time(from 1978-12 to 2015-12)?and I don't kown if my options is right?

sissalVE
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Location: University of Copenhagen

Re: Velocity is too large near open boundary

#5 Post by sissalVE »

Hi,
Could you show your bathymetry of both sides of the open boundary and your grid?

hezhi
Posts: 10
Joined: Wed Apr 11, 2018 2:31 pm
Location: FIO

Re: Velocity is too large near open boundary

#6 Post by hezhi »

Those are my bathymetry.
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Last edited by hezhi on Wed Dec 23, 2020 12:17 pm, edited 2 times in total.

hezhi
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Joined: Wed Apr 11, 2018 2:31 pm
Location: FIO

Re: Velocity is too large near open boundary

#7 Post by hezhi »

These are bathymetry of open boundary.
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kate
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Re: Velocity is too large near open boundary

#8 Post by kate »

There are reanalyses out there at better than monthly, starting before 1979. You might have to contact the authors and mail them some harddrives to load it onto to get it, though. A colleague of mine has done that to get both SODA and Mercator.

sissalVE
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Joined: Wed Feb 21, 2018 2:08 am
Location: University of Copenhagen

Re: Velocity is too large near open boundary

#9 Post by sissalVE »

To me it looks like the issue is at the northern boundary. You could try to either expand the grid to start further north at -5, or so, depending on the bathymetry. So that the bathymetry at the boundary is less steep. Or reduce the Eastern ( or is it really the Western?) boundary to 60 degrees instead of 50.

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