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<div>Hi, </div>
<div>I want to calculate the first two terms of vorticity equation separately.</div>
<div><br>
</div>
<div> VOR = i(dw/dy – dv/dp) + j(du/dp – dw/dx) + k(dv/dx – du/dy)</div>
<div> </div>
<div>I want to calculate the first and second term separately. I wrote the fortran code of x and y horizontal vorticity by utilizing the potential vorticity code of wrf_pvo.f. </div>
<div><br>
</div>
<div>Both codes runs fine but I am suspicious about the accuracy of my code. It appears that the sign of the vorticity is changed and the code calculates +ve vorticity as –ve and vice a versa.</div>
<div><br>
</div>
<div>I am copying the fortran code for both terms that I call in ncl using WRAPIT and will greatly appreciate if someone could have a look and advice if I have made any mistake. I am not cc'ing it to WRFHELP since talking to wrfhelp for such problems is generally
waste of time.</div>
<div><br>
</div>
<div>For the first term (dw/dy - dv/dp) I wrote the following code:</div>
<div>
<div><br>
</div>
<div><br>
</div>
<div>C NCLFORTSTART</div>
<div> SUBROUTINE xvort(XV,U,V,W,PRS,MSFU,MSFV,MSFT,COR,DX,DY,</div>
<div> + NX,NY,NZ,NXP1,NYP1)</div>
<div><br>
</div>
<div> IMPLICIT NONE</div>
<div> INTEGER NX,NY,NZ,NXP1,NYP1</div>
<div> DOUBLE PRECISION U(NXP1,NY,NZ),V(NX,NYP1,NZ), W(NX,NY,NZ)</div>
<div> DOUBLE PRECISION PRS(NX,NY,NZ), XV(NX,NY,NZ)</div>
<div> DOUBLE PRECISION MSFU(NXP1,NY),MSFV(NX,NYP1),MSFT(NX,NY)</div>
<div> DOUBLE PRECISION COR(NX,NY)</div>
<div> DOUBLE PRECISION DX,DY</div>
<div>C NCLEND</div>
<div> INTEGER KP1,KM1,JP1,JM1,IP1,IM1,I,J,K</div>
<div> DOUBLE PRECISION DSY,DSX,DP,DWDY,DVDP</div>
<div> DOUBLE PRECISION XVOR,DTHDX,DTHDY,MM</div>
<div><br>
</div>
<div> </div>
<div> DO K = 1,NZ</div>
<div> KP1 = MIN(K+1,NZ)</div>
<div> KM1 = MAX(K-1,1)</div>
<div> DO J = 1,NY</div>
<div> JP1 = MIN(J+1,NY)</div>
<div> JM1 = MAX(J-1,1)</div>
<div> DO I = 1,NX</div>
<div> IP1 = MIN(I+1,NX)</div>
<div> IM1 = MAX(I-1,1)</div>
<div><br>
</div>
<div> DSX = (IP1-IM1)*DX</div>
<div> DSY = (JP1-JM1)*DY</div>
<div> MM = MSFT(I,J)*MSFT(I,J)</div>
<div>
<div><br>
</div>
<div> DWDY = 0.5D0* (W(I,JP1,K)/MSFU(I,JP1)+</div>
<div> + W(I+1,JP1,K)/MSFU(I+1,JP1)-</div>
<div> + W(I,JM1,K)/MSFU(I,JM1)-</div>
<div> + W(I+1,JM1,K)/MSFU(I+1,JM1))/DSY*MM</div>
<div><br>
</div>
<div> DP = PRS(I,J,KP1) - PRS(I,J,KM1)</div>
<div> DVDP = 0.5D0* (V(I,J,KP1)+V(I,J+1,KP1)-V(I,J,KM1)-</div>
<div> + V(I,J+1,KM1))/DP</div>
<div><br>
</div>
<div> XVOR = DWDY - DVDP</div>
<div> XV(I,J,K) = XVOR*1.D2</div>
<div> END DO</div>
<div> END DO</div>
<div> END DO</div>
<div><br>
</div>
<div><br>
</div>
<div> RETURN</div>
<div> END</div>
</div>
</div>
<div>
<hr align="center" size=""3"" width=""95%"">
</div>
<div>For the second term (du/dp – dw/dx), I wrote the following code:</div>
<div><br>
</div>
<div>
<div>C NCLFORTSTART</div>
<div> SUBROUTINE yvort(YV,U,V,W,PRS,MSFU,MSFV,MSFT,COR,DX,DY,</div>
<div> + NX,NY,NZ,NXP1,NYP1)</div>
<div><br>
</div>
<div> IMPLICIT NONE</div>
<div> INTEGER NX,NY,NZ,NXP1,NYP1</div>
<div> DOUBLE PRECISION U(NXP1,NY,NZ),V(NX,NYP1,NZ), W(NX,NY,NZ)</div>
<div> DOUBLE PRECISION PRS(NX,NY,NZ), YV(NX,NY,NZ)</div>
<div> DOUBLE PRECISION MSFU(NXP1,NY),MSFV(NX,NYP1),MSFT(NX,NY)</div>
<div> DOUBLE PRECISION COR(NX,NY)</div>
<div> DOUBLE PRECISION DX,DY</div>
<div>C NCLEND</div>
<div> INTEGER KP1,KM1,JP1,JM1,IP1,IM1,I,J,K</div>
<div> DOUBLE PRECISION DSY,DSX,DP,DWDX,DUDP</div>
<div> DOUBLE PRECISION YVOR,DTHDX,DTHDY,MM</div>
<div><br>
</div>
<div> print*,'nx,ny,nz,nxp1,nyp1'</div>
<div> print*,DX,DY,NX,NY,NZ</div>
<div> DO K = 1,NZ</div>
<div> KP1 = MIN(K+1,NZ)</div>
<div> KM1 = MAX(K-1,1)</div>
<div> DO J = 1,NY</div>
<div> JP1 = MIN(J+1,NY)</div>
<div> JM1 = MAX(J-1,1)</div>
<div> DO I = 1,NX</div>
<div> IP1 = MIN(I+1,NX)</div>
<div> IM1 = MAX(I-1,1)</div>
<div><br>
</div>
<div> DSX = (IP1-IM1)*DX</div>
<div> DSY = (JP1-JM1)*DY</div>
<div> MM = MSFT(I,J)*MSFT(I,J)</div>
<div><br>
</div>
</div>
<div><br>
</div>
<div>
<div><br>
</div>
<div> DWDX = 0.5D0* (W(IP1,J,K)/MSFV(IP1,J)+</div>
<div> + W(IP1,J+1,K)/MSFV(IP1,J+1)-</div>
<div> + W(IM1,J,K)/MSFV(IM1,J)-</div>
<div> + W(IM1,J+1,K)/MSFV(IM1,J+1))/DSX*MM</div>
<div><br>
</div>
<div> DP = PRS(I,J,KP1) - PRS(I,J,KM1)</div>
<div> DUDP = 0.5D0* (U(I,J,KP1)+U(I+1,J,KP1)-U(I,J,KM1)-</div>
<div> + U(I+1,J,KM1))/DP</div>
<div><br>
</div>
<div> YVOR = DUDP - DWDX</div>
<div> YV(I,J,K) = YVOR*1.D2</div>
<div> END DO</div>
<div> END DO</div>
<div> END DO</div>
<div><br>
</div>
<div><br>
</div>
<div> RETURN</div>
<div> END</div>
</div>
<div><br>
</div>
<div><br>
</div>
<div>Best regards and thanks in advance for the help</div>
<div><br>
</div>
<div>
<div> <span style="color: rgb(66, 66, 66); ">b:)</span></div>
<div>
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