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<div dir="auto">Dear MITgcm users,<br />
<br />
I encountered a problem when trying to apply a barotropic tide (u=u0*sin(wt)) at the only open boundary (east side) of my model domain. Firstly I used the script /seaice_obcs/input.tide/mk_tide.m to generate input files and keep the M2 constituent only:<br />
<span style="color:black;font-family:Courier New;font-size: 10pt">% specify (0.1 m/s, 1 hr) for East boundary tidal component 1</span><span style="font-size: 10pt"><br /></span><span style="color:black;font-family:Courier New;font-size: 10pt">if strcmp(ob,'E')</span><span style="font-size: 10pt"><br /></span><span style="color:black;font-family:Courier New;font-size: 10pt"> tmp(:,2:end) = 0; %Set dummy components</span><span style="font-size: 10pt"><br /></span><span style="color:black;font-family:Courier New;font-size: 10pt"> if strcmp(fld,'am')</span><span style="font-size: 10pt"><br /></span><span style="color:black;font-family:Courier New;font-size: 10pt"> tmp(:,1) = tmp(:,1) + 0.1;</span><span style="font-size: 10pt"><br /></span><span style="color:black;font-family:Courier New;font-size: 10pt"> else</span><span style="font-size: 10pt"><br /></span><span style="color:black;font-family:Courier New;font-size: 10pt"> tmp(:,1) = tmp(:,1) + 1 * 3600;</span><span style="font-size: 10pt"><br /></span><span style="color:black;font-family:Courier New;font-size: 10pt"> end</span><span style="font-size: 10pt"><br /></span><span style="color:black;font-family:Courier New;font-size: 10pt">end</span><span style="font-size: 10pt"><br /></span><span style="font-size: 10pt"><br /></span>However, this generated really small velocity (close to zero) at the boundary. Even if I cranked up the amplitude, the output velocity increased but still much smaller than the prescribed magnitude. Then instead of generating the tidal input files, I made a direct modification of the eastern boundary velocity as OBEu = u0*sin(wt) in the “obcs_calc.F” file, which gave the expected results. So I’m wondering if anyone could share some experience of generating the example tidal input files, and is it a safe way to modify the boundary velocity in obcs_calc.F directly? Thanks for your time!<br />
<br />
Best, Weiyang<br />
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<div class="matchFont"><b>Weiyang Bao</b>
<div dir="auto">Ph.D. Student, Physical Ocean Science and Engineering</div>
<div dir="auto">School of Marine Science and Policy</div>
<div dir="auto">University of Delaware</div>
<div dir="auto">wbao@udel.edu</div>
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