<div dir="ltr"><div><div>To calculate the horizontal pressure gradient, you will need pressure on a constant height surface. If you have that, then the command to compute the pressure gradient is<br><br></div>'define pgrad = cdiff(pres,x)/dx + cdiff(pres,y)/dy',<br>
<br><br></div><div>where the array holding pressure values is "pres" and you have defined dx and dy as<br></div><div>'define dx = 6.371e6*cos(lat*3.14159/180)*cdiff(lon*3.14159/180,x)'<br></div><div>'define dy = 6.371e6*cdiff(lat*3.14159/180)'<br>
<br></div><div>where the 3.14159/180 term is used to translate degrees to radians.<br><br></div><div>To calculate the geopotential height gradient, you need height on a constant pressure surface. If you have that, then the command to compute the geopotential height gradient is<br>
<br></div><div>'define gphgrad = cdiff(gheight,x)/dx + cdiff(gheight,y)/dy'<br></div><div><br>where the same commands as above were used to define dx and dy.<br><br>Jeff Duda<br></div></div><div class="gmail_extra">
<br><br><div class="gmail_quote">On Thu, Apr 4, 2013 at 7:02 AM, Simona Skyraite <span dir="ltr"><<a href="mailto:skyraite@gmail.com" target="_blank">skyraite@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr"><br><div class="gmail_quote"><br><div dir="ltr"><div><div><div><div>Hello,<br><br></div>How to calculate pressure gradient (hPa/100 km) and geopotential height gradient? Could someone explain step by step how to do that?"<br>
<br><br></div></div>Thanks in advance! <br></div><span class="HOEnZb"><font color="#888888"><div><font color="#888888">Simona</font><br></div></font></span></div></div><br><br clear="all"></div>
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<br></blockquote></div><br><br clear="all"><br>-- <br>Jeff Duda<br>Graduate research assistant<br>University of Oklahoma School of Meteorology<br>Center for Analysis and Prediction of Storms<br>
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