European Centre for Medium Range Weather Forecasts Model Data (ECMWF)
Information updated on June 18, 2008, 10:01 pm GMT
General Data Description
ACRF purchases the gridded operational analysis product from ECMWF Operatational Analysis and Forecasting System covering a large area of the TWP, including all TWP ACRF sites. These files are provided in GRIB format and are converted to netCDF.
These data can only be distributed to ARM scientists.
ARM scientists who obtain these data must agree to acknowledge use of the
data in their publications and not to share the data with others who are
not on the ARM Science Team.
Derived data are defined as data from which the ECMWF fields cannot be
re-created.
Such data can be freely distributed by ARM scientists.
The distribution of raw ECMWF fields to third parties is not allowed
without the explicit permission of ECMWF. This is the general rule
for all data supplied by ECMWF.
Permission can be requested to supply data to groups outside the
ARM project for specific projects. In such cases, if permission was
given, a conditions form would be produced by ECMWF to be signed by
the principal investigator of such a group.
Data Stream Names
- ecmwfdarsupp - ECMWF: supplemental data, Darwin
netCDF File Header Description (Data Object Design File) - ecmwfdarsurf - ECMWF: surface measurement, Darwin
netCDF File Header Description (Data Object Design File) - ecmwfdarupa - ECMWF: upper air measurement, Darwin
netCDF File Header Description (Data Object Design File) - ecmwfmansupp - ECMWF: supplemental data, Manus
netCDF File Header Description (Data Object Design File) - ecmwfmansurf - ECMWF: surface measurement, Manus
netCDF File Header Description (Data Object Design File) - ecmwfmanupa - ECMWF: upper air measurement, Manus
netCDF File Header Description (Data Object Design File) - ecmwfnausupp - ECMWF: supplemental data, Nauru
netCDF File Header Description (Data Object Design File) - ecmwfnausurf - ECMWF: surface measurement, Nauru
netCDF File Header Description (Data Object Design File) - ecmwfnauupa - ECMWF: upper air measurement, Nauru
netCDF File Header Description (Data Object Design File) - ecmwfsupp - ECMWF: supplemental data, entire coverage
netCDF File Header Description (Data Object Design File) - ecmwfsurf - ECMWF: surface measurement, entire coverage
netCDF File Header Description (Data Object Design File) - ecmwfupa - ECMWF: upper air measurement, entire coverage
netCDF File Header Description (Data Object Design File)
Measurement Description
- twpecmwf[xxx]suppX1.c1
-
All the fields except for the cloud cover contain values which
have been accumulated over 6 hours since the start of the forecast.
- surface sensible heat flux ((W/m^2)*s),
- surface latent heat flux ((W/m^2)*s),
- surface solar radiation ((W/m^2)*s),
- surface thermal radiation ((W/m^2)*s),
- top solar radiation ((W/m^2)*s),
- top thermal radiation ((W/m^2)*s),
- East/West surface stress ((N/m^2)*s),
- North/South surface stress ((N/m^2)*s),
- total cloud cover (0-1).
- surface solar radiation downward ((W/m^2)*s),
- surface thermal radiation downward ((W/m^2)*s).
Beginning with the January 2006 files, the following two measurements have been added:
- Convective precipitation (m),
- Large scale precipitation (m).
- twpecmwf[xxx]surfX1.c1
- surface fields:
- surface pressure (Pa),
- u,v at 10m (m/s),
- temperature at 2m (K),
- dew point at 2m (K),
- snow depth (m (water))* ,
- MSL pressure (Pa),
- orography (m^2/s^2),
- land-sea mask (0,1) ,
- surface roughness (m),
- albedo
- sub-surface fields:
- total column water (kg/m^2),
- skin temperature (K).
+ Beginning on 2000-06-27, ECMWF issued a new model cycle (22r3) in which soil wetness level 1 is replaced by volumetric soil water layer 1 (m^3/m^3).
The following measurements were added beginning in October 2000:
- sea surface temperature (K)
- low cloud cover (0-1)
- medium cloud cover (0-1)
- high cloud cover (0-1)
- twpecmwf[xxx]upaX1.c1
- The "Upper Air" measurements are all given at the 15 model levels:
1000, 925, 850, 700, 500, 400, 300, 250, 200, 150, 100, 70, 50, 30, 10
hPa.
- geopotential (m^2/s^2),
- temperature (K),
- vertical velocity (Pa/s),
- u- velocity (m/s),
- v-velocity (m/s),
- relative humidity %.
Temporal Coverage
Area Covered
Data Stream Inputs
twpecmwfsuppX1.00
twpecmwfsurfX1.00
twpecmwfupaX1.00
Notification Form Link
Contacts
- ARM Mentor Jim Mather
- ARM Software Developer Laurie Gregory
Data User Notes
- Acknowledgment:
- Publications should refer to: "The ECMWF operational analysis and forecasting system: The full evolution http://www.ecmwf.int/products/data/operational_system/index.html"
- twpecmwf[xxx]suppX1.c1
- ECMWF introduced a major operational archive change on 2000-09-12
which affects first guess data. Supplementary fields data are extracted from
first guess fields and are thus affected. ECMWF has changed the data
assimilation period in the 4-D variational analysis data assimilation
system from 6 to 12 hours.
Analyses are still produced every 6 hours as previously.
Previously the first guess data consisted of 6 hour forecasts from the times 00, 06, 12, and 18 UTC. Under the new 12 hour assimilation cycle, this is replaced by 12 hour forecasts from the times 00 and 12 UTC. Thus data from base time 6 at forecast step 6 under the previous system are replaced by data from base time 00 at forecast step 12 under the new scheme. All data which had a base time of 06 or 18 UTC under the old scheme have a similar change.
- Reading GRIB formatted files
- Information on reading GRIB formatted files can be found at: Reading netCDF, HDF, and GRIB Files
Acronyms
DAR Darwin, Australia ECMWF European Centre for Medium Range Forecasting FKB Black Forest, Germany GRIB GRIdded Binary MAN Manus, Papua New Guinea NAU Nauru, Republic of Nauru NIM Niamey, Niger, Africa NSA North Slope of Alaska PYE Point Reyes, California SGP Southern Great Plains TWP Tropical Western Pacific