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CFMIP / COSPv2.0

COSP - The CFMIP (Cloud Feedbacks Model Intercomparison Project) Observation Simulator Package
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Bug in MODIS indexing of pressure input #31

Closed brhillman closed 5 years ago

brhillman commented 5 years ago

There appears to be a bug in the column indexing of the pressure input variable to the MODIS simulator. The calls to modis_subcolumn on lines 903-913 of cosp.F90 contain the following:

          do i = 1, modisIN%nSunlit
             call modis_subcolumn(modisIN%Ncolumns,modisIN%Nlevels,modisIN%pres(i,:),    &
                                  modisIN%tau(int(modisIN%sunlit(i)),:,:),               &
                                  modisIN%liqFrac(int(modisIN%sunlit(i)),:,:),           &
                                  modisIN%g(int(modisIN%sunlit(i)),:,:),                 &
                                  modisIN%w0(int(modisIN%sunlit(i)),:,:),                &
                                  isccp_boxptop(int(modisIN%sunlit(i)),:),               &
                                  modisRetrievedPhase(i,:),                              &
                                  modisRetrievedCloudTopPressure(i,:),                   &
                                  modisRetrievedTau(i,:),modisRetrievedSize(i,:))
          end do

It appears that most of the inputs are using the modisIN%sunlit array to index into just the sunlit columns, however modisIN%pres does not use this indexing here. As a result, it appears that for groups of columns that contain both sunlit and not-sunlit columns, there will be a mismatch between the pressure profiles and the other inputs used. It appears as though modisIN%pres(i,:) should be replaced with modisIN%pres(int(sunlit(i)),:) here.

dustinswales commented 5 years ago

@brhillman There is not a bug. It is done @line717. Awkward, yes, but there's some history behind this (which currently evades me)

brhillman commented 5 years ago

Oh weird. Okay I'll close.