<div><font>Hi Jean-Michel,</font></div><div><font><br></font></div><div><font>Thank you for your details. I see the tricks here, which is very helpful for my </font>purpose.</div><div><br></div><div><br></div><div><sign signid="0"><div><div style="color:#909090;font-family:Arial Narrow;font-size:12px"></div></div><div style="font-size:14px;font-family:Verdana;color:#000;">
<div> <font size="2">Best regards<br>-----------------------------------------<br>Yu-Kun Qian (Ç®îÚÀ¤)</font><div style="font-family: Verdana;"><span style="font-size: small;">South China Sea Institute of Oceanology</span></div><font size="2" style="font-family: Verdana;">Sun Yat-sen University<br>Xingang West Road, Haizhu District<br>Guangzhou, P.R. China<br>Email: <u><font color="#0000ff">qianyukun@scsio.ac.cn</font></u>, <a href="mailto:qianyk@mail2.sysu.edu.cn">qianyk@mail3.sysu.edu.cn</a></font></div><div> <font size="2"> </font> </div>
</div></sign></div><div> </div><div><includetail><div> </div><div style="font:Verdana normal 14px;color:#000;"><div style="FONT-SIZE: 12px;FONT-FAMILY: Arial Narrow;padding:2px 0 2px 0;">------------------ Original ------------------</div><div style="FONT-SIZE: 12px;background:#efefef;padding:8px;"><div id="menu_sender"><b>From: </b> "Jean-Michel Campin"<jmc@mit.edu>;</div><div><b>Date: </b> Wed, May 25, 2022 00:40 AM</div><div><b>To: </b> "MITgcm-support"<mitgcm-support@mitgcm.org>; <wbr></div><div></div><div><b>Subject: </b> Re: [MITgcm-support] vertical momentum tendency</div></div><div> </div><div style="position:relative;"><div id="tmpcontent_res"></div>Hi Yu-Kun,<br><br>Regarding diagnostic TOTVTEND, it's filled up with the same variable "vVel"<br>two times in diagnostics_fill_state.F,<br>the first time at the begining of the time step, with a negative sign (tmpFac = -86400/detaTMom), <br>and the second time at the end of the time step, with a positive sign (tmpFac = +86400/delaTMom).<br>This way we get the difference of vVel between the end of time-step and begining of time-step.<br>Note that the second time it's filled up we don't increment the counter (the 7th argument is<br>-1 instead of +1).<br><br>I have the impression that if you follow the same double filling for TOTWTEND it <br>should work.<br><br>Cheers,<br>Jean-Michel<br><br>On Tue, May 24, 2022 at 05:40:48PM +0800, ?????? wrote:<br>> Hi Martin,<br>> <br>> <br>> Thank you for your suggestion. I follow your method and integrate the divergence tendency<br>> to get W-tendency, with the output at dt frequency (so that the true tendency can be verified).<br>> This is indeed a way to get TOTWTEND but the tendency computed as (W[t+1]-W[t])/dt seems<br>> to have a dt/2 offset relative to the divergence way. So the difference cannot be minimized<br>> up to machine accuracy.<br>> <br>> Since I need to close the energy budget to machine accuracy, I may need the online TOTWTEND<br>> and decide to add a user-defined diagnostic for this. It is somewhat confusing that the following<br>> three lines (see here):<br>> CALL DIAGNOSTICS_SCALE_FILL( uVel, tmpFac, 1, 'TOTUTEND',0,Nr,0,1,1,myThid )<br>> CALL DIAGNOSTICS_SCALE_FILL( vVel, tmpFac, 1, 'TOTVTEND',0,Nr,0,1,1,myThid )<br>> CALL DIAGNOSTICS_SCALE_FILL( wVel, tmpFac, 1, 'TOTWTEND',0,Nr,0,1,1,myThid )<br>> do not give similar results. The first two lines indeed fill TOTUTEND/TOTVTEND with tendency of<br>> <br>> u/v, whereas the third line fill TOTWTEND with vertical velocity itself (magnified by 86400).<br>> <br>> <br>> Can somebody help me resolve this?<br>> <br>> <br>> Best regards <br>> <br>> -----------------------------------------<br>> Yu-Kun Qian (??????)South China Sea Institute of Oceanology<br>> Sun Yat-sen University<br>> Xingang West Road, Haizhu District<br>> Guangzhou, P.R. China<br>> Email: qianyukun@scsio.ac.cn, qianyk@mail3.sysu.edu.cn<br>> <br>> <br>> <br>> <br>> <br>> <br>> ------------------ ???????? ------------------<br>> ??????: "Martin Losch"<Martin.Losch@awi.de>;<br>> ????????: 2022??5??23??(??????) ????10:33<br>> ??????: "MITgcm-support"<mitgcm-support@mitgcm.org>; <br>> <br>> ????: Re: [MITgcm-support] vertical momentum tendency<br>> <br>> <br>> <br>> I am not sure, if this is a useful comment, but even in a non-hydrostatic simulation, the flow field is non-divergent and you coiuld diagnose wVel from the vertical integral of the horizontal divergence (in fact, the model does this in a non-hydrostatic simulation, too). In the same way, and since the operations are linear you coud diagnose dw/t from - \nabla_h du/dt, couldn??t you?<br>> <br>> Martin<br>> <br>> On 23. May 2022, at 15:36, ?????? <qianyk@mail3.sysu.edu.cn> wrote:<br>> <br>> Hi,<br>> <br>> <br>> I might find a workaround to get instantaneous TOTWTEND (not time-mean one)<br>> by adding the following lines:<br>> CALL DIAGNOSTICS_SCALE_FILL( wVel, tmpFac, 1, 'TOTWTEND',0,Nr,0,1,1,myThid )<br>> to diagnostics_fill_state.F file, following TOTUTEND and TOTVTEND (see here). And<br>> also add a call to <br>> CALL DIAGNOSTICS_ADDTOLIST()<br>> at diagnostics_main_init.F (see here).<br>> <br>> <br>> Then I re-compile the model and run it well. However, the tendency of w TOTWTEND<br>> seems to be much larger than expected in my case:<br>> <7239677D@602E0261.C58D8B62.png><br>> <br>> <br>> I am not sure DIAGNOSTICS_SCALE_FILL really do the time-differencing. Is this<br>> the right way to get TOTWTEND? Why it looks so large in magnitude?<br>> <br>> <br>> <br>> Best regards <br>> <br>> -----------------------------------------<br>> Yu-Kun Qian (??????)South China Sea Institute of Oceanology<br>> Sun Yat-sen University<br>> Xingang West Road, Haizhu District<br>> Guangzhou, P.R. China<br>> Email: qianyukun@scsio.ac.cn, qianyk@mail3.sysu.edu.cn<br>> <br>> <br>> <br>> <br>> ------------------ ???????? ------------------<br>> ??????: "Matthew Mazloff"<mmazloff@ucsd.edu>;<br>> ????????: 2022??5??18??(??????) ????9:47<br>> ??????: "MITgcm-support"<mitgcm-support@mitgcm.org>; <br>> <br>> ????: Re: [MITgcm-support] vertical momentum tendency<br>> <br>> <br>> <br>> Hi Haoron<br>> <br>> Dump snapshots at the interval you need to get dW/dt.<br>> <br>> <br>> For example daily tendency would be derived from <br>> frequency(1) = -86400.0,<br>> timePhase(1) = 0.0,<br>> fields(1,1) = 'WVEL ',<br>> filename(1) = ??WvelSnap??,<br>> <br>> <br>> <br>> <br>> Matt<br>> <br>> <br>> On May 17, 2022, at 5:47 PM, ?????? <qianyk@mail3.sysu.edu.cn> wrote:<br>> <br>> Hi Haoran,<br>> <br>> <br>> Thank you for your help. But I don't really know how these two diagnostics<br>> could help in deriving the tendency of w (unit of acceleration).<br>> <br>> <br>> My understanding is that these two diagnostics are useful in calculating the<br>> eddy momentum flux when the output is time-average <> one. For example,<br>> <w'u'> = <wu> - <w><u><br>> If we output monthly mean wu, w, and u, we can get eddy flux <w'u'> for this<br>> month.<br>> <br>> <br>> <br>> Best regards <br>> <br>> -----------------------------------------<br>> Yu-Kun Qian (??????)South China Sea Institute of Oceanology<br>> Sun Yat-sen University<br>> Xingang West Road, Haizhu District<br>> Guangzhou, P.R. China<br>> Email: qianyukun@scsio.ac.cn, qianyk@mail3.sysu.edu.cn<br>> <br>> <br>> <br>> <br>> <br>> <br>> ------------------ ???????? ------------------<br>> ??????: "Haoran Xu"<xu1jian2wei3@163.com>;<br>> ????????: 2022??5??17??(??????) ????7:40<br>> ??????: "MITgcm-support"<mitgcm-support@mitgcm.org>; <br>> <br>> ????: Re: [MITgcm-support] vertical momentum tendency<br>> <br>> <br>> <br>> Hi??<br>> If I understand correctly,these two diagnostics could help.<br>> <br>> <br>> <br>> <br>> WU_VEL |WU LR|m.m/s^2 |Vertical Transport of Zonal Momentum WV_VEL |WV LR|m.m/s^2 |Vertical Transport of Meridional Momentum<br>> <br>> <br>> Haoran Xu.<br>> <br>> <br>> <br>> <br>> At 2022-05-17 18:30:48, "??????" <qianyk@mail3.sysu.edu.cn> wrote:<br>> Hi all,<br>> <br>> <br>> Just a quick question. Why there is no tendency of vertical momentum,<br>> like TOTWTEND, in the diagnostics even the non-hydrostatic option is<br>> turned on?<br>> <br>> <br>> To close the energy budget, I guess we need this diagnostic. Is there any<br>> workaround to obtain it if there is no TOTWTEND?<br>> <br>> <br>> <br>> <br>> Best regards.<br>> <br>> ---------------------------<br>> Yu-Kun Qian (??????)<br>> South China Sea Institute of Oceanology<br>> <br>> Sun Yat-sen University <br>> Xingang West Road, Haizhu District <br>> Guangzhou, P.R. China<br>> Email: qianyk@mail3.sysu.edu.cn <br>> <br>> <br>> <br>> <br>> <br>> <br>> <br>> <br>> <br>> <br>> <br>> <br>> _______________________________________________<br>> MITgcm-support mailing list<br>> MITgcm-support@mitgcm.org<br>> https://urldefense.proofpoint.com/v2/url?u=http-3A__mailman.mitgcm.org_mailman_listinfo_mitgcm-2Dsupport&d=DwICAg&c=-35OiAkTchMrZOngvJPOeA&r=HSHS34ROdfL7f2oVxuKB761hrMvWN1RWA5k3SHGts_s&m=3dmk9mE5wbsK8pGhM9ik2Mywehebv53YMmvBG-OJeJ1YILefVCNpFtkCisx_V2rL&s=-KY9LHIxlYVAlDaSW3axV0lhAZkr0gMbYyogCKxqBQs&e= <br>> <br>> <br>> <br>> <br>> <br>> <br>> <br>> _______________________________________________<br>> MITgcm-support mailing list<br>> MITgcm-support@mitgcm.org<br>> http://mailman.mitgcm.org/mailman/listinfo/mitgcm-support<br><br>> _______________________________________________<br>> MITgcm-support mailing list<br>> MITgcm-support@mitgcm.org<br>> http://mailman.mitgcm.org/mailman/listinfo/mitgcm-support<br><br>_______________________________________________<br>MITgcm-support mailing list<br>MITgcm-support@mitgcm.org<br>http://mailman.mitgcm.org/mailman/listinfo/mitgcm-support<br></div></div><!--<![endif]--></includetail></div>