NCEP Operational Air Quality Forecast Change Log

Updated: June 10, 2005

 North East Operational Domain Forecasts


Model Run


   June 10, 2005
  00 Z Run
 A bug was corrected in the interpolation  of ozone from the new GFS T382 to the CMAQ 12 km grid.  This has helped reduce ozone overpredictions found in runs from  May 31-June 10, 2005.
  May 31, 2005
  12 Z GFS Upgrade
The NCEP Global Forecast System (GFS) was upgraded to T382 (~35 km).
In addition, the following implementations were changed:
  • A new land/sea ice physics
  • Reduced vertical diffusion
  • Enhanced mountain blocking
  • assimilation of AIRS satellite data
GFS ozone is used to prescribe the CMAQ lateral Boundary Conditions above 6 km.
  May 3, 2005
  12 Z NAM-12 CMAQ Operational (1X domain)
  Upgraded NAM-12.   Upgraded CMAQ  :
   PREMAQ updated to use NAM-12 1 km landuse data
    Minor CMAQ updates to version 4.4
    2002 Point/Area Source Emissions projected for 2005
    Updated Mobile 6 source emissions

May 1, 2004

12 Z Eta-12

CMAQ Experimental

Implemented Experimental System

2002  Point/Area Source Emissions Projected for 2004

Updated Mobile 6 mobile source emissions

6 hour initial condition cycling

Use of GFS ozone predictions for CMAQ upper Lateral Boundary Conditions

March 2004 Eta-12 implementation

48 hour forecasts for both 06 and 12 UTC runs

May 5, 2004

12 Z Experimental

Correction to 6 hour Cycling system. Now turned on.

May 17, 2004

12 Z Experimental

Correction to GFS ozone LBC ingest.  Now working.

May 26, 2004

12z Experimental

Sfc ozone Grib files now available on /com/aqm/prod

July 20, 2004  


1. Limited  GFS LBC  ozone ingest to above 6 km AGL (CMAQ sigma lvl 18)
2. Specification of  a minimum mixing coefficiant (Kz) in CMAQ pbl routines
   *  Allows for lower Kz in rural areas than urban at night :  reduces  nightime O3 overprediction in rural  areas
   * Prevents precursor concentrations in urban areas becoming too large at night and
     thereby reduces overtitration in urban areas (more mixing in urban areas at nght)


NCEP FVS verification system



System Component


June 1, 2005
 Grid2obs VSDB records
 VSDB exceedence records (FHO) now being produced for daily maximum 1 and 8 hour ozone predictions.
March 25, 2005
Grid2obs VSDB
 VSDB file generation turned on for 2005 Ozone season:
Backward averaged convention used for both Airnow bufr and cmaq forecasts
L1L2 and FHO statistics now computed (except daily maximums)
 2004 FVS VSDB File changes

May 31, 2004

Grid2obs VSDB records  

VSDB records (L1,L2) begun for NE domain on 146 grid using forward averaged BUFR observations
June 9-June 20
BUFR generation
BUFR software changed at EPA to produce backward averages. 
VSDB records not produced
June 21, 2004
BUFR Generation
BUFR softward changed at EPA to produce foreward averages for NCO data tanks.
Bufr tanks and VSDB records for June 9-20 recreated with foreward avging
July 12, 2004
VSDB records
VSDB records are now computed for East US domain on Grid 146, 142
Subdomain records computed for all grids (eg: NEC, SEC,APL...)

July 22, 2004     

3X VSDB Records      

VSDB records computed for developmental 3x domain (Grid 142) over full domain, and subregions, and over 1 x domain
August 1, 2004 VSDB records VSDB subdomains updated to new FVS regions.  MDW, GMC and  LMV now
replace NMW, SMW (midwest) subregions.
August 1, 2004
FHO VSDB records
Began creating  1h & 8 h VSDB FHO records for events :
1hr ozone > 20, 40, 65, 85, 105, 125 ppb
8h avg ozone > 20, 40, 65, 85 ppb


Summer 2003 North East Domain Forecasts



Model Run


June 25, 2003

12 Z Eta-12 – CMAQ Experimental

Implemented Experimental System with 24 hour ozone initialization cycling.

Used Spring 2003 Eta-12 implementation

July 23-24

12 Z Experimental

CMAQ Archives lost

July 31- August 4

12 Z Experimental

Cold Start Runs…No cycling

August 5

12 Z NCO run


Transfer to NCO

Cold Start…no cycling

August 5

06Z Experimental

06Z implemented

6 hour cycling (6z only)

August 15

06 Z Experimental

Cold Start

August 20

06 Z NCO

12 Z NCO

Transfer of 6 hour cycling to NCO for 6 and 12 Z runs.

Cold Start

September 9

06 Z, 12 Z NCO

Eta-Post:  landuse, soiltype variable packing fixed.  Previously landuse values incorrectly packed to equal 0 (Ocean) or 10.