## 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 (EP A) and the U.S. Department of Commerce’ s National Oceanic and Atmospheric Administration (NOAA) and under agreement number DW13921548. A lthough it has been reviewed by EP A 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 23 rd h values for 24 th 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 É ric 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