NOTE: The nws-changes mailing list is no longer active. The list archives are made available for historical reasons.
-------- Original Message -------- 063 NOUS41 KWBC 301342 PNSWSHTechnical Implementation Notice 12-41
National Weather Service Headquarters Washington DC 942 AM EDT Thu Aug 30 2012To: Subscribers:
-Family of Services
-NOAA Weather Wire Service
-Emergency Managers Weather Information Network
-NOAAPORT
Other NWS Partners, Users and Employees
From: Tim McClung
Chief, Science Plans Branch
Office of Science and Technology
Subject: New NGAC Aerosol Forecast System
Effective September 11, 2012
Effective on or about Tuesday, September 11, 2012, the
National Centers for Environmental Prediction (NCEP) will
begin to run and disseminate data from the NOAA
Environmental Modeling System Global Forecast System (GFS)
Aerosol Component (NGAC).
NGAC is NCEPs global in-line atmospheric-aerosol module
within GFS. The aerosol component of the NGAC is the Goddard
Chemistry Aerosol Radiation and Transport Model (GOCART).
Funded mainly by NASAs Earth Science programs, the GOCART
model was developed to simulate common atmospheric aerosols
(sulfate, black carbon (BC), organic carbon (OC), dust, and
sea-salt), CO, and sulfur gases.
NGAC Version 1 provides 5-day forecasts of aerosol dust
proxies and five dust particle size ranges listed below,
once per day for the 0000 UTC cycle. The NGAC output will be
available in GRIB2 format on a 1x1 degree output grid, with
output available for 00 to 120 hours, with output every
3 hours. The NGAC output will be disseminated via NCEP's
ftp/http server at the following location:
http://www.ftp.ncep.noaa.gov/pub/data/nccf/com/ngac
ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/ngac
Output files and their contents include:
(1) ngac.t00z.a2df$HR, where HR=00, 03, ...,120:
2D products including
AER_OPT_DEP_at550: dust aerosol optical depth at 550nm
(dimensionless)
CR_AER_SFC_MASS_CON: coarse mode surface mass concentration
(kg/m3)
FN_AER_SFC_MASS_CON: fine mode surface mass concentration
(kg/m3)
CR_AER_COL_MASS_DEN: coarse mode column mass density (kg/m2)
FN_AER_COL_MASS_DEN: fine mode column mass density kg/m2
DUST_EMISSION_FLUX: dust emission fluxes (kg/m2/sec)
DUST_SEDIMENTATION_FLUX: dust sedimentation fluxes
(kg/m2/sec)
DUST_DRY_DEPOSITION_FLUX: dust dry deposition fluxes
(kg/m2/sec)
DUST_WET_DEPOSITION_FLUX: dust wet deposition fluxes
(kg/m2/sec)
(2) ngac.t00z.a3df$HR, where HR=00, 03, ..., 120:
3D products at model levels including PRES: pressure (Pa) RH: relative humidity (%) TEMP: temperature (K) DUST1: dust bin1 (0.1-1 micron) mixing ratio (kg/kg) DUST2: dust bin2 (1-1.8 micron) mixing ratio (kg/kg) DUST3: dust bin3 (1.8-3 micron) mixing ratio (kg/kg) DUST4: dust bin4 (3-6 micron) mixing ratio (kg/kg) DUST5: dust bin5 (6-10 micron) mixing ratio (kg/kg) (3) ngac.t00z.aod_$NM, where NM=11p1um, 1p63um, 340nm, 440nm, 550nm, 660nm, 860nm: Aerosol optical depth at specified wavelengths (11.1, 1.63, 0.34, 0.44, 0.55, 0.66, and 0.86 micron) A consistent parallel feed of data is currently available on the NCEP server via the following URL's:ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/ngac/para
or http://www.ftp.ncep.noaa.gov/data/nccf/com/ngac/para Users please note that NGAC products are encoded in GRIB2 using a relatively-new GRIB template. Users should download the latest versions of wgrib2 and the other NCEP GRIB utilities to use the NGAC output products. Many of these utilities were updated on July 17, 2012. Users can access the NCEP GRIB utilities from this URL: http://www.nco.ncep.noaa.gov/pmb/codes/nwprod/util/exec A Website containing more information about NCEP's dust product can be found at: http://www.emc.ncep.noaa.gov/gmb/sarah/NGAC/html/realtime.ng ac.html For questions regarding the scientific content of the NGAC model please contact: Sarah Lu NCEP/EMC College Park, Maryland 20740 301-683-3733 Sarah.Lu@xxxxxxxx For questions regarding the dataflow aspects of these data sets please contact: Rebecca Cosgrove NCEP/NCO Dataflow Team College Park , Maryland 20740 301-683-0567 ncep.list.pmb-dataflow@xxxxxxxx NWS National Technical Implementation Notices are online at:http://www.nws.noaa.gov/os/notif.htm $$
nws-changes archives: