What’s New in MCIP2?

Tanya L. Otte*

Atmospheric Modeling Division

U.S. EPA ORD National Exposure Research Laboratory

Research Triangle Park, NC

*On assignment from NOAA Air Resources Laboratory.

Disclaimer: The research presented here was performed under the Memorandum of 

Understanding between the U.S. Environmental Protection Agency (EPA) and the U.S. 

Department of Commerce’s National Oceanic and Atmospheric Administration (NOAA) and 

under agreement number DW13921548. Although it has been reviewed by EPA and NOAA

and approved for publication, it does not necessarily reflect their views or policies.
New Release – MCIPv2.3

Passed on to CMAS for release.

Contains several minor modifications.

Includes community input.

Should upgrade MCIP with new CMAQ.

Tested on IBM and Linux (PG Compiler)

Details in CHANGES file and in preprint.

Most notable changes discussed here.
(1) Added Graupel to Output

Accommodates advanced mixed-phase 

schemes in MM5: Reisner II, GSFC, 

Schultz

If available, QG is passed through.

Requires new CMAQ to use in chemistry.

Omitting graupel (if in MM5 output) can be 

significant.
Graupel vs. Microphysical Species
(2) P-X VEGFRC Work-Around

NCAR bug in MM5v3.5; fix in MM5v3.6.2

In solve.F, VEGFRC updated every 24 h 

after init to unrealistic value for P-X

Using bad P-X VEGFRC leads to negative 

dry deposition velocities one hour per day

Work-around uses 23rd h values for 24th h
Example of Bad VEGFRC in P-X
(3) Full Jacobian to Output

Fields initially removed in MCIPv2.2.

Fields now needed for correction to CMAQ 

vertical diffusion algorithm.

Adds JACOBF (levels 1 – NLAYS) to 

METCRO3D.

Adds JACOBS (level 0 = ground) to 

METCRO2D.
(4) P-X Variables for BEIS 3.12

Fields initially removed in MCIPv2.2.

Fields used, if available, for BEIS 3.12.

Restored SOIT1, SOIT2, SOIM1, SOIM2, 

and SLTYP to METCRO2D, if P-X in MM5.
(5) GRIDDESC Formatting

GRIDDESC from MCIP2 had minor error.

Added a line containing ‘ ’ to top of output.

Also attempted to generalize number 

formats for improved portability.

– On some machines, numbers with “E” format 

in FORTRAN appear in scientific notation, 

which cannot be read successfully.

Can edit old GRIDDESC files manually, 

if needed.
(6) Restored GRIDBDY2D

File initially removed in MCIPv2.2.

Users initializing CMAQ from other models 

(e.g., global apps) need lat/lon coords of 

lateral boundaries.

GRIDBDY2D contains lat/lon & land use.

File is very small (10s of KB).
(7) Error-Checking on Layers

Added in MCIPv2.2 to prevent users from 

defining top and bottom layers thinner 

than in MM5.

Error-checking not robust for same as 

MM5, due to real-number round-off.

Introduced robust error-checking to avoid 

real-number comparisons.
(8) 10-m Winds

Users interested in meteorology 

verification from MCIP output.

Added 10-m wind speed and direction for 

comparison with “surface” observations.

Diagnosed (NOT passed through).

– Similarity theory for speed.

– Assume no directional shear for direction.

WSPD10 and WDIR10 in METCRO2D.
(9) 2-m Temperature

Most popular PBL schemes in MM5 now 

directly output 2-m temperature.

New field TEMP2 in METCRO2D.

Has not been tested in SMOKE.

Should be used in place of both TEMP1P5

and TEMP10. Do not use with TEMP10.
TEMP2 vs. TEMP1P5
(10) Optional GRID Files

Newer emphasis on annual simulations.

GRID files are static in time.

Namelist logical (“makegrid”) via script 

variable MKGRID.

makegrid = .F. shuts off all GRID files.

May need to create files seasonally for 

non-hydrostatic base state in MM5.
(11) Explicit Geometry Calculations

Old: dot-point latitude, longitude, and map-scale 

factors bilinearly interpolated from cross-points.

Added explicit calculation.

Slight differences in contravariant winds. (O:10-7)

More significant differences expected for large 

domains, and far from projection center.

Need to modify earth radius in const_mod.F if 

changed in MM5.
(12) Eliminate Fields of “Missing” 

Old: Output all microphysics fields and P-X 

fields, regardless of presence in MM5

Can lead to serious waste of space, 

especially with new QG field (now 5 3D Q)

Change to code is transparent to user
(13) Land Use Updates

Changed DLUSE in GRIDCRO2D to be 

USGS-based MM5 land use, if not 

rediagnosing PBL and not RADM dry dep

– No impact, unless using field outside std code

Removed 5 unsupported land use options

– Land use can only be passed from MM5

– Fractional land use not directly supported

– LUPROC output not supported (fixed proj)

– Other deleted options were developmental 
(14) Polar Stereographic/Mercator

Old: I/O API headers for Mercator and 

polar stereographic were incorrect

Should not have impacted CMAQ 

processing, but caused problems in PAVE

Could use M3EDHDR to update 

New release corrects  settings
(15) Minimum PBL Height (Eta)

MM5 implementation of M-Y Eta PBL 

scheme can have negative PBL heights

Can lead to negative WSTAR, sometimes 

can crash CMAQ

New minimum of top of lowest full layer to 

prevent very small and negative values
Summary

New release, MCIPv2.3

No serious bug fixes, many minor updates

Should consider upgrading to MCIPv2.3 

because of new features

Will need to upgrade MCIP and CMAQ 

concurrently
Looking Ahead

MCIP for WRF

– Based on U. Houston IMAQS “WCIP”

– WRF-EM initially

MCIP for toxics

– Mercury, chlorine, others

– To be user option in standard release

Checks of I/O API libraries against code 

using IOPARMS3 (in I/O API version 3)
Credits

Bret Anderson

Santosh Chandru

Carlie Coats

Rafik Djouad

Robert Gilliam

Éric Giroux

Andy Hawkins

Jinyou Liang

Rohit Mathur

Luca Delle Monache

Jon Pleim

Todd Plessel

Maria Prodanova-Boiadjieva

Pedro Sanhueza

Donna Schwede

Jeff Stehr

Narisara Thongboonchoo

Brian Timin

Shaheen Tonse

Zion Wang

David Wong

Aijun Xiu

Jeff Young

Alexis Zubrow