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<p class="MsoNormal"><span style="font-size:11.0pt">Hi MITgcm devel,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">In an effort to make our output more comprehensible to outsiders I think we should consider updating the names of some of our diagnostic output descriptions.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">First, terms such as UVELMASS and UTHMASS are not “Zonal components of velocity”, they are the component of velocity in the model grid’s ‘x’ direction. In the LLC tiles, 6 of the 13 tiles (or 2 of 5 faces)
are rotated by 90 degrees so that flow in the ‘+x’ direction is actually negative quasi-meridional. Moreover, with the Arctic Cap tile 7 (face 3) flow in the positive ‘x’ direction is eastward along its bottom edge (first row) and westward along its upper
edge (last row). A similar story applies for flow in the +y direction. So, can we change these names to reflect the fact that ‘u’ and ‘v’ are defined not by the compass but by the local orientation of the curvilinear grid?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Second, the name ‘MASS’ and the description ‘Mass-Weighted’ is also somewhat misleading because these terms are not weighted by mass at all, but by hFac. Perhaps a more descriptive term would be ‘Geometry-Weighted’
or some other name that reflects the possible non-unity value of hFac?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">This topic has come up many times since we’ve adopted the LLC grids for the ECCO Central Production and other projects. I’d like to see this sorted out to reduce the confusion that seems to hit everybody
encountering these variables for the first time. <o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<ul style="margin-top:0in" type="disc">
<li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo1"><span style="font-size:11.0pt">Ian<o:p></o:p></span></li></ul>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<pre><span style="color:black">45 |UVELMASS| 50 | 46 |UUr MR|m/s |Zonal Mass-Weighted Comp of Velocity (m/s)<o:p></o:p></span></pre>
<pre><span style="color:black">46 |VVELMASS| 50 | 45 |VVr MR|m/s |Meridional Mass-Weighted Comp of Velocity (m/s)<o:p></o:p></span></pre>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:black">50 |UTHMASS | 50 | 51 |UUr MR|degC.m/s |Zonal Mass-Weight Transp of Pot Temp<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:black">51 |VTHMASS | 50 | 50 |VVr MR|degC.m/s |Meridional Mass-Weight Transp of Pot Temp<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
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