[MITgcm-support] Problems with continuity equation for atmosphere

[Yuan Lian]

Hi,

I am having trouble to validate the continuity equation for atmosphere 
model.
The continuity equation in P-coordinate is given by:

du/dx+dv/dy+dw/dp=0    (1)

Here d/dx, d/dy and d/dp are partial differentials.

du/dx+dv/dy+dw/dp has the same order of magnitude as du/dx, dv/dy and dw/dp
when calculated from uVel, vVel and wVel. It is not close to zero as I 
assumed.

I also tried to use the same equation in integrate_for_w.F which 
calculates the vertical
velocity by continuity equation. However, I was not able to get the same 
vertical
velocity as wVel when using uVel and vVel.

Does anyone have the same problem? Did I miss anything here? Thanks!

regards,
Yuan




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128 jmc      1.11 C-  o Free Surface case (r-Coordinate):

129 adcroft  1.6  C      non zero at surface ; zero under-ground and at 
r_lower boundary

130 jmc      1.11         IF (k.EQ.Nr) THEN

131 jmc      1.8            DO j=1,sNy
132                          DO i=1,sNx

133 jmc      1.11              wFld(i,j,k,bi,bj) =
134                    &              -( uTrans(i+1,j)-uTrans(i,j)
135                    &                +vTrans(i,j+1)-vTrans(i,j)
136                    &               )*recip_rA(i,j,bi,bj)
137                    &         *maskC(i,j,k,bi,bj)
138                    &         *recip_deepFac2F(k)*recip_rhoFacF(k)

139 adcroft  1.6             ENDDO

140 adcroft  1.2            ENDDO

141 adcroft  1.6          ELSE

142 jmc      1.8            DO j=1,sNy
143                          DO i=1,sNx

144 jmc      1.11              wFld(i,j,k,bi,bj) =
145                    &        ( 
wFld(i,j,k+1,bi,bj)*deepFac2F(k+1)*rhoFacF(k+1)
146                    &              -( uTrans(i+1,j)-uTrans(i,j)
147                    &                +vTrans(i,j+1)-vTrans(i,j)
148                    &               )*recip_rA(i,j,bi,bj)
149                    &        )*maskC(i,j,k,bi,bj)
150                    &         *recip_deepFac2F(k)*recip_rhoFacF(k)

151 adcroft  1.6             ENDDO
152                         ENDDO
153                       ENDIF


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