NCEP
CONUS Experimental Run Air Quality Forecast Change
Log
Date |
Experimental Model Run |
Change |
2011-2012 CONUS EXPERIMENTAL RUNS | ||
June 1, 2012 | 12 UTC |
|
June 1, 2011 | 12 UTC |
|
|
2010 CONUS EXPERIMENTAL RUNS |
|
July 6, 2010 | 12 UTC |
|
May 26, 2010 |
18 UTC |
|
May 1, 2010 | CONUS 12 UTC |
|
2009 | ||
August 12,
2009 |
CONUS 12 UTC |
|
May 1, 2009 | 12 Z |
|
2008 | ||
December 16, 2008 | 12Z | Changes
to the NAM driving meteorological model forecast system:
|
August 19, 2008 | 12Z Cycle | The biogenic emission files for the experimental run CB05 chemical mechanism were incorrect and did not include some secondary organic aerosols. The point source emission files were also incorrect. These files were corrected for the experimental run mechanism. Retrospective testing showed that ozone forecasts were decreased by 3-4 ppb overall while developmental PM 2.5 forecast products were increased slightly. |
June 12, 2008 | 06Z Cycle | PM2.5 developmental product predicted from the experimental run was computed incorrectly with updated CB05 emissions. The primary organic aerosol emission was given in carbonaceous mass instead of aerosol mass. The error resulted in an underestimate of PM2.5 since the upgraded emissions were implemented on June 10, 2008. |
June 10, 2008 |
06Z Cycle |
Specific experimental run system improvements include:
These additional products are restricted to designated scientists and state forecasters through the EMC restricted access AQF web page. |
Summer 2007 Experimental Run Changes |
||
September 18, 2007 | 12 Z run | Experimental CONUS Run moved to operational Status |
July 18, 2007 | 12 Z run | 1. An error in the dry deposition velocity calculation
was
identified and corrected for selected species (NO, NO2, and CO). The
error is associated with the mesophyll resistance which was erroneously
set to zero. The impact is a reduction in deposition velocity and a
resultant increase in predicted concentrations of these species. Higher
NOx concentrations then result in higher predicted O3 concentrations.
Test simulations confirm this trend with widespread enhancements in
predicted O3 in regions with vegetation (primarily in the East U.S.).
The max 8-hr O3 increased by 2-5ppb for cases during May and June 2007.
The direction of the predicted O3 change was in the correct direction,
i.e., reduction in under-estimation in the current version. 2. An error was corrected in the plume-rise calculations to use the correct pressure fields estimated from the NAM Hybrid vertical coordinate. Test cases during June 2007 showed minimal impact. |
June 12, 2007 | 12 Z run |
|
May 29, 2007 | 18 Z run |
|
May 25, 2007 | 12 Z run |
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May 16, 2007 | 00 Z run |
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May 4, 2007 | 12 Z run |
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May 1, 2007 | 12 Z run |
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Summer 2006 Experimental Changes |
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September 5, 2006 | 18 Z run | PREMAQ met processing calculations of vertical eddy diffusivities were mistakenly set from the 1st 22 layers from the NAM 60 layer predictions rather than for the actual 22 CMAQ layers. This adversely impacted the vertical advection in the PREMAQ Jacobian calcluations by increasing vertical diffusion in CMAQ. This was corrected and impact can be evaluated from Lee, Slides 7-17 |
September 5, 2006 | 12 Z run | CMAQ now driven by updates to NAM model (additional NAM-Y changes implemented) that include increase to horizontal diffusion and corrections to SST initial conditions. |
August 15, 2006 | 12 Z run | CMAQ now driven by NAM-Y meteorology which was implemented into NAM slot. NAM-Y had corrections to vertical and horizontal diffusion and lake SST initialization which resulted in more realistic warmer,dryer boundary layers that increase production of ozone. Impacts can be evaluated from Lee, Slides 7-17. |
Augus 04, 2006 | 18 Z cycle | CRISIS
Fix: Some Point Source Emissions were
still configured for 2005 . These emissions files were
updated for 2006 projections. CRISIS FIX: Major errors found in the tightly coupled PREMAQ emissions processor. Isoprene biogenic emissions were never set, causing strong ozone underpredictions in the tightly coupled 5X CMAQ runs. Also, some arrays were improperly dimensioned causing array bound errors. For impact, see Mathur, slides 20-25 |
July 12, 2006 | 00Z cycle | Most Emissions updated with 2006 Projections |
June 8,
2006 |
06Z cycle |
WRF-CMAQ tightly coupled runs
were
available late for this case only at 18:40 UTC. Removal of
GFS
ozone interpolation
scripts(since GFS ozone no longer used for CMAQ) and optimizing job
procedures are being tested for quicker turn
around. |
May 8,
2006 |
18Z cycle |
WRF-CMAQ tightly
coupled system
transferred to NCO 4x/day parallel testing and replaces the
parallel NAM-Eta CMAQ system. 6 hour cycling turned on for CMAQ initialization. 06 and 12 UTC cycles are run to 48 hours. |
April
12, 2006 |
12Z Cycle |
WRF-CMAQ
tight
vertical coupling
Testing CMAQ driven by NAM-WRF
parallel run with tight vertical
coupling (using the same Sigma-p Pressure hybrid vertical
coordinate). WRF NMM output on all 60 sigma-pressure hybrid
layers
now read in by PREMAQ and collapsed to 22 CMAQ model layers.
These 22 layers are a subset of the WRF 60 level system.
|
SUMMER 2005 Developmental Run Changes |
||
Aug. 20,
2005 |
12Z Cycle |
Cold
start. Aug. 19 warm start rerun but not in time to initialize Aug. 20 cold start. Aug. 17 run GRIB output not created. |
July 26,
2005 |
12Z Cycle |
CMAQ CONUS
Run now using
ACM approach to parameterize deep convection and
photolysis
attenuation from NAM clear sky radiation predictions and
static
lateral boundary conditions (ozone at
lbcs=100ppb). This was done to correct overmixing of ozone downward in high terrain. |
July 16,
2005 |
12Z Cycle |
CONUS Run
w/S3 convection
modified to use static lateral boundary conditions (ozone at
lbcs=100ppb). This was done to correct overmixing of ozone downward in high terrain. Problem may be related to CMAQ mass adjustment scheme and NAM interpolated winds that cause spurious vertical motions near model top. |
July 9,
2005 |
12Z Cycle |
CONUS Run modified
to
replace ACM convective mixing scheme with Standard CMAQ mixing scheme
except with downward convective mixing turned off (S3) This was done to correct overmixing of ozone downward in high terrain. |
June 29,
2005 |
12Z Cycle |
CONUS run
was
restarted. This first run was initialized as a cold start (no
atm. chemistry init fields). However, updated emissions are
used. Successive runs(6/30/05 and on) will use 24 hour
cycling to
initialize CMAQ atm. chemistry with a previous runs 24 hour forecast. |
June 24,
2005 |
12Z Cycle |
NCEP
Develop machine
crashed. No CONUS runs available due to this hardware
problem. We
expect CONUS runs to be available again soon with a cold start
initialization (no cycling). |
June 17,
2005 |
12Z Cycle |
GFS Ozone
predictions are used
to specify the CMAQ lateral boundaries at only the CMAQ model top level
(100 mb, level 22). This appears to help overprediction over
the
Rocky Mountain areas. |
June 01,
2005 |
12
Z Cycle |
The CONUS AQF (5X)
48 hour
Forecasts were begun with the following options:
|