# Problems on Create Initial and Boundary Conditions from Seasonal Average Hemispheric CMAQ Output

**URL:** <https://forum.cmascenter.org/t/problems-on-create-initial-and-boundary-conditions-from-seasonal-average-hemispheric-cmaq-output/924>\
**Category:** CMAQ\
**Created:** [September 10, 2019, 5:57am UTC](https://forum.cmascenter.org/t/problems-on-create-initial-and-boundary-conditions-from-seasonal-average-hemispheric-cmaq-output/924 "2019-09-10T05:57:44Z")\
**Posts on this page:** 8\
**Page:** 2

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**Author:** ![eyortizd](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.cmascenter.org/eyortizd/32/847_2.png) [@eyortizd](https://forum.cmascenter.org/u/eyortizd)\
**Post date:** [September 29, 2020, 7:17pm UTC](https://forum.cmascenter.org/t/problems-on-create-initial-and-boundary-conditions-from-seasonal-average-hemispheric-cmaq-output/924/21 "2020-09-29T19:17:43Z")

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Hi,

I’m trying to use CMAQ 5.3.1 over Bogotá, Colombia, and I used Equatorial Mercator as projection in WRF domains, and I created MCIP files with EM projection, but when I ran ICON I get this error

“LAT/LON calculations for GDTYP3D 7 not supported”

Could you suggest me any solution for my problem? There’s a way to fix it without changing Projection system? if not, What do you consider the best projection to work in equatorial zones?

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**Author:** ![barronh](https://avatars.discourse-cdn.com/v4/letter/b/85e7bf/32.png) [@barronh](https://forum.cmascenter.org/u/barronh)\
**Post date:** [September 29, 2020, 7:47pm UTC](https://forum.cmascenter.org/t/problems-on-create-initial-and-boundary-conditions-from-seasonal-average-hemispheric-cmaq-output/924/22 "2020-09-29T19:47:07Z")

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When we ran Bogota, we used an alternative ICON/BCON processor. The most recent incarnation is at [https://github.com/barronh/aqmbc](https://github.com/barronh/aqmbc).

Using the standard tools is always nice. It looks like it would be a relatively easy fix to ICON/BCON. In the common/lat\_lon.F, each grid has an initialization and than a conversion. You’d need to add the same thing for EQM. Below is a quick attempt to copy the Polar Stereographic

```auto
      ELSE IF ( GDTYP .EQ. EQMGRD3) THEN ! Equatorial Mercator

         IF ( .NOT. SETEQM( SNGL( P_ALP ), ! first, initialize
     & SNGL( P_BET ), ! for EQM2LL()
     & SNGL( P_GAM ),
     & SNGL( XCENT ),
     & SNGL( YCENT ) ) ) THEN
            MSG='Equatorial mercator projection setup error for CTM CONC file'
            CALL M3EXIT ( PNAME, 0, 0, MSG, 2 )
         END IF

         X = X0 + FLOAT( COL ) * SNGL( XCELL )
         Y = Y0 + FLOAT( ROW ) * SNGL( YCELL )
         IF ( .NOT. EQM2LL( X, Y, LON, LAT ) ) THEN
            MSG = 'Equatorial mercator conversion error for CTM CONC file'
            CALL M3EXIT ( PNAME, 0, 0, MSG, 2 )
         END IF

```

You would insert this before the unsupported coordinates section. Then, you’d need to recompile icon and test it.

When you get to BCON, you’ll have to do the same thing there.

[1] [https://github.com/USEPA/CMAQ/blob/master/PREP/icon/src/common/lat\_lon.F](https://github.com/USEPA/CMAQ/blob/master/PREP/icon/src/common/lat_lon.F)  
[2] [https://github.com/USEPA/CMAQ/blob/master/PREP/bcon/src/common/lat\_lon.F](https://github.com/USEPA/CMAQ/blob/master/PREP/bcon/src/common/lat_lon.F)

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<div class="post-metadata">

**Author:** ![eyortizd](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.cmascenter.org/eyortizd/32/847_2.png) [@eyortizd](https://forum.cmascenter.org/u/eyortizd)\
**Post date:** [September 29, 2020, 8:59pm UTC](https://forum.cmascenter.org/t/problems-on-create-initial-and-boundary-conditions-from-seasonal-average-hemispheric-cmaq-output/924/23 "2020-09-29T20:59:37Z")

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Thank You Barron, I’m going to try aqmbc option

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**Author:** ![hogrefe.christian](https://avatars.discourse-cdn.com/v4/letter/h/74df32/32.png) [@hogrefe.christian](https://forum.cmascenter.org/u/hogrefe.christian)\
**Post date:** [September 29, 2020, 9:10pm UTC](https://forum.cmascenter.org/t/problems-on-create-initial-and-boundary-conditions-from-seasonal-average-hemispheric-cmaq-output/924/24 "2020-09-29T21:10:19Z")

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The edits posted by Barron to modify lat\_lon.F in the icon and bcon src/common directories should do the trick.

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**Author:** ![jsm2093](https://avatars.discourse-cdn.com/v4/letter/j/b4bc9f/32.png) [@jsm2093](https://forum.cmascenter.org/u/jsm2093)\
**Post date:** [May 30, 2021, 2:49pm UTC](https://forum.cmascenter.org/t/problems-on-create-initial-and-boundary-conditions-from-seasonal-average-hemispheric-cmaq-output/924/25 "2021-05-30T14:49:07Z")

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Dear @fliu,

I have created IC conditions based on the github tutorial. Although the simulation was successful I have doubts about the created netcdf file since I see a very large resolution. I attached an image of my obtained result. Could you tell me if you got a similar result?

I have used CCTM\_CONC\_v53beta2\_intel17.0\_HEMIS\_cb6r3m\_ae7\_kmtbr\_m3dry\_2016\_quarterly\_av.nc and for meteorology files the files given in the CCTM tutorial [CMAQ/CMAQ\_UG\_tutorial\_benchmark.md at master · USEPA/CMAQ · GitHub](https://github.com/USEPA/CMAQ/blob/master/DOCS/Users_Guide/Tutorials/CMAQ_UG_tutorial_benchmark.md)

![ic_CMAQ](https://canada1.discourse-cdn.com/flex027/uploads/cmas/original/2X/2/25a38eedd46f7fa3d72affbcc049426c1cbe5287.png)

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<div class="post-metadata">

**Author:** ![hogrefe.christian](https://avatars.discourse-cdn.com/v4/letter/h/74df32/32.png) [@hogrefe.christian](https://forum.cmascenter.org/u/hogrefe.christian)\
**Post date:** [May 30, 2021, 10:01pm UTC](https://forum.cmascenter.org/t/problems-on-create-initial-and-boundary-conditions-from-seasonal-average-hemispheric-cmaq-output/924/26 "2021-05-30T22:01:58Z")

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The hemispheric simulation from which the quarterly average concentrations were derived was performed on a polar stereographic grid with a horizontal grid spacing of 108 km. When ICON generates initial conditions in regridding mode, the regridding is performed by determining the closest grid cell of the coarse domain (in this case hemispheric) for each grid cell in the fine grid (target domain). Therefore, the spatial patterns of the initial conditions generated by ICON retain the resolution of the coarse grid from which they are derived.

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<div class="post-metadata">

**Author:** ![jsm2093](https://avatars.discourse-cdn.com/v4/letter/j/b4bc9f/32.png) [@jsm2093](https://forum.cmascenter.org/u/jsm2093)\
**Post date:** [May 31, 2021, 8:49am UTC](https://forum.cmascenter.org/t/problems-on-create-initial-and-boundary-conditions-from-seasonal-average-hemispheric-cmaq-output/924/27 "2021-05-31T08:49:48Z")

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@hogrefe.christian thanks for your clear explanation.

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<div class="post-metadata">

**Author:** ![lizadams](https://avatars.discourse-cdn.com/v4/letter/l/49beb7/32.png) [@lizadams](https://forum.cmascenter.org/u/lizadams)\
**Post date:** [April 10, 2023, 6:43pm UTC](https://forum.cmascenter.org/t/problems-on-create-initial-and-boundary-conditions-from-seasonal-average-hemispheric-cmaq-output/924/28 "2023-04-10T18:43:15Z")

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