NCEP Developmental Run Air Quality Forecast Change Log


 CONUS Developmental Run Forecasts

 

Date

PM Model Run

Change
2008 Developmental Run Changes
December 16, 200812ZChanges to the NAM  driving meteorological model forecast system:
  1. The background for the first (tm12) analysis in each NDAS run is now from the GDAS instead of the previous NDAS run (so-called "partial cycling"). Land states are still fully cycled from the previous NDAS cycle.
  2. WRF-NMM Model changes (also implemented into the DGEX):
    1. The PBL/turbulance schemes were modified to mix each hydrometeor species in the vertical.
    2. To apply vertical diffusion for separate water species, the model was changed so that (a) it can apply vertical diffusion to an arbitrary number of species, (b) the counter gradient option can be applied to some or all of the species if desired, and (c) option to set to zero some or all of the surface fluxes is also made available.
    3. In the radiation parameterization, the absorbtion coefficients for water and ice have been doubled to 1600 and 1000, respectively
    4. Changes to land-sfc physics:
      1. Let the potential evaporation decrease linearly with Bulk Richardson number under stable condition, and weighted by snow coverage.
      2. Let the slope of saturated humidity function wrt temperature decrease linearly with snow coverage.
  3. Changes to GSI analysis
    1. Use latest (1Q 2008) version of the GSI analysis code
    2. Assimilate METOP radiance data
    3. Assimilate TAMDAR/AMDAR aircraft data
    4. New version of Communitity Radiative Transfer Model
  4. Use AFWA 1/16 bedient snow depth analysis
  5. Use WPS (instead of WRF-SI) codes to process GDAS first guess input files, which are used as a first guess to the first (tm12) GSI analysis in the NDAS
  August 19, 2008    12Z CycleThe  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 15, 200806 Z cycleAerosol developmental outputs are produced from AQF experimental runs with CB05/AERO-4 chemistry mechanisms.  See experimental change log  and CB05/AERO-4 descriptions for overview and further changes  Developmental CMAQ run turned off..

Specific experimental run system improvements include:

  • The CB05 chemical mechanism with more detailed Volatile Organic Compound (VOC) chemistry was implemented. 
  • A harmonized version of the AERO-4 aerosol chemistry mechanism was turned on. The harmonized NOx night time chemistry is configured with heterogeneous pathways turned off but gas-phase N205 hydrolysis turned on.  This was done to minimize the impact of aerosol chemistry on the ozone foreceast.
  • Sea salt emissions were included in CMAQ.
  • Point, area and mobile emissions were upgraded based upon recent EPA National Emissions Inventory (NEI,  2005) and then projected for the current year. EGU sources use 2006 CEM data projected for 2008.  These emissions are also consistent with the CB05 chemical mechanism. 
  • For mobile sources, the  EPA Office of  Transportation and Air Quality (OTAQ ) was used in addition to 2005 NEI v1 emission data sets.  Use of OTAQ on-road emission estimates is a departure from the temperature dependent regression approach used in previous years.
  • Experimental and Developmental products from these runs are now cycled every 6 hours with forecasts to 48 hours at both 06 and 12 Z cycles.
  • Impacts of these potential changes are shown here
Additional Developmental Products:
 These additional products are  restricted to designated scientists and  state forecasters through the EMC  restricted access AQF web page.
June 12, 2008 06Z Cycle Developmental run (CBM4/Aero-3) PM2.5 products were computed incorrectly with updated CBM4 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 used for this run beginning May 13, 2008.  
June 10, 2008
   06Z Cycle
May 13,   2008  06Z Cycle

Specific system improvements include:

  • Point, area and mobile emissions were upgraded based upon recent EPA National Emissions Inventory (NEI,  2005) and then projected for the current year. EGU sources use 2006 CEM data projected for 2008.  These emissions are also consistent with the CBM4 chemical mechanism. 
  • For mobile sources, the  EPA Office of  Transportation and Air Quality (OTAQ ) was used in addition to 2005 NEI v1 emission data sets.  Use of OTAQ on-road emission estimates is a departure from the temperature dependent regression approach used in previous years.
2007 Developmental Run Changes
Nov. 12, 2007  06Z Cycle
  • Minimum eddy diffusivity used in ACM-2 reduced from 0.5 to 0.1 m^2/s to agree with operational run.
October 10, 2007  06Z Cycle
  • BL mixing scheme in CMAQ has been change from RADM version 2.6 (Byun et al. 1999) using the NAM TKE PBL height to Asymmetric Convective Model-2 (ACM-2) using a Richardson calculation in PREMAQ (Jon Pleim, JAMC, 2007).
July 18, 2007  06Z Cycle Deposition velocity and plume-rise errors corrected (See Experimental Run description)
May 16, 2007  06Z cycle Mobile emissions were missing from experimental run since May 1. Therefore, mobile emissions not included in CMAQ predictions from May 1-15, 2007.  Mobile emissions updated for 2007 projections are now included.
 May 1/ 4, 2007 06Z Cycle Static emissions (point, area) updated for 2007 projections updated
Updated California Non-Road NEI 2002 inventories
9/6-9/7/06 06Z Cycle PM runs failed with problems with development machine. Sept. 14 run initialized with 48 hour forecast from previous runs.
Sept. 6 and 7th predictions missing.
September 5, 2006 18Z 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 evaluatedThis was corrected and impact can be evaluated from Lee, Slides 7-17 
September 5, 2006 12Z 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. TsiTT
August 01, 2006  06Z Cycle  Some Point  Source Emissions were still configured for 2005 .  These emissions files were updated for 2006 projections.  PM10 file also updated for the aerosol run.

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   06Z Cycle  Most  Emissions updated for 2006 projections
 July 5, 2006
   06Z Cycle
  Cold start for PM run.
 July 1-4, 2006
   06Z Cycles
 PM runs failed.  Error creating directories on wx22mc.
 June 30, 2006
   06Z Cycle
 CONUS 48 hour forecast PM run moved to Blue to avoid shut downs of runs during critical weather days.  Expect this run to complete at around 1 PM EDT with full surface and profile plots available by 4 PM EDT.
 PM run forecast length extended to 48 hours.
 June 20, 2006
   06Z Cycle
  Primary PM run domain extended to cover all of CONUS
 June 12, 2006
   06Z Cycle
  PM run limited to 36 hour forecasts to meet wall clock 3 hour limit
 June 11, 2006
   06Z cycle
  PM run crashed after 0.9 hours
 June 10, 2006
   06Z cycle
  PM run crashed after 41 hours
 June 09, 2006
  06Z Cycle
Eastern U.S. run stopped after 39 hours.
 June 08,2006
  06Z Cycle
 Tight vertical coupling PREMAQ code now fixed. 
Eastern U.S. Runs are now initiated once/day at 06Z to avoid compute traffic occurring later in the day.
 May 26, 2006-June 08, 2006
  
 Testing of CONUS PM fails when WRF tightly coupled system tested.  Tightly coupled run turned off and are currently being debugged.
April 1, 2006
  12 Z Cycle
 Loosely coupled NAM-Eta-CMAQ w/ Anthropogenic aerosol emissions and aerosol chemistry run once/day with forecasts to 24 hours :
  • Binkowski RPM aerosol module
  • Eastern U.S. domain:  268x259 x22 CMAQ sigma level coordinates
  • ACM convective parameterization
  • Photolysis attenuation from NAM clear sky radiation
  • Static lateral boundary conditions
  • Optimized lateral advection scheme for faster run times
  • 24 hour cycling
Prediction vertical profiles are available