European Centre for Medium Range Weather Forecasts Diagnostic Analyses (ECMWFDIAG)
Information updated on March 24, 2009, 6:46 pm GMT
General Data Description
Diagnostic Analyses data are derived from ECMWF model runs in simulated vertical profiles of diagnostic variables at specific locations or for area averages. The Physical Parametrization Group at ECMWF generates these data as a courtesy to ARM for all the ACRF sites including the changing location of the mobile facility.
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
- ecmwfdarflx - ECMWF: radiative fluxes at altitude, Darwin, 1-hr avg
netCDF File Header Description (Data Object Design File) - ecmwfdarsfc1l - ECMWF: surface variables and fluxes, Darwin, 1-hr avg
netCDF File Header Description (Data Object Design File) - ecmwfdarsfce - ECMWF: near-surface and surface variables (extra), Darwin, 1-hr avg
netCDF File Header Description (Data Object Design File) - ecmwfdarsfcml - ECMWF: model multilevel surface fields at 4 levels, Darwin
netCDF File Header Description (Data Object Design File) - ecmwfdarten - ECMWF: model, total and physical tendencies for met and cloud vars, Darwin, 1-hr
netCDF File Header Description (Data Object Design File) - ecmwfdarvar - ECMWF: model met. and cloud variables at altitude, Darwin
netCDF File Header Description (Data Object Design File) - ecmwfflx - ECMWF: radiative fluxes at altitude, 1-hr avg, entire coverage
netCDF File Header Description (Data Object Design File) - ecmwfmanflx - ECMWF: radiative fluxes at altitude, Manus, 1-hr avg
netCDF File Header Description (Data Object Design File) - ecmwfmansfc - ECMWF: surface variables and fluxes, Manus, 1-hr avg
netCDF File Header Description (Data Object Design File) - ecmwfmansfc1l - ECMWF: surface variables and fluxes, single layer, Manus, 1-hr avg
netCDF File Header Description (Data Object Design File) - ecmwfmansfce - ECMWF: near-surface and surface variables (extra), Manus, 1-hr avg
netCDF File Header Description (Data Object Design File) - ecmwfmanten - ECMWF: model, total and physical tendencies for met and cloud vars, Manus, 1-hr avg
netCDF File Header Description (Data Object Design File) - ecmwfmanvar - ECMWF: model met. and cloud variables at altitude, Manus, 1-hr avg
netCDF File Header Description (Data Object Design File) - ecmwfnauflx - ECMWF: radiative fluxes at altitude, Nauru, 1-hr avg
netCDF File Header Description (Data Object Design File) - ecmwfnausfc - ECMWF: surface variables and fluxes, Nauru, 1-hr avg
netCDF File Header Description (Data Object Design File) - ecmwfnausfc1l - ECMWF: surface variables and fluxes, single layer, Nauru, 1-hr avg
netCDF File Header Description (Data Object Design File) - ecmwfnausfce - ECMWF: near-surface and surface variables (extra), Nauru, 1-hr avg
netCDF File Header Description (Data Object Design File) - ecmwfnauten - ECMWF: model, total and physical tendencies for met and cloud vars, Nauru, 1-hr avg
netCDF File Header Description (Data Object Design File) - ecmwfnauvar - ECMWF: model met. and cloud variables at altitude, Nauru 1-hr avg
netCDF File Header Description (Data Object Design File) - ecmwfsfc - ECMWF: surface variables and fluxes, entire coverage, 1-hr avg
netCDF File Header Description (Data Object Design File) - ecmwfsfc1l - ECMWF: surface variables and fluxes, single layer, 1-hr avg
netCDF File Header Description (Data Object Design File) - ecmwfsfce - ECMWF: near-surface and surface variables (extra), entire coverage, 1-hr avg
netCDF File Header Description (Data Object Design File) - ecmwfsfcml - ECMWF: model multilevel surface fields at 4 levels, entire coverage
netCDF File Header Description (Data Object Design File) - ecmwften - ECMWF: total and physical tendencies for met and cloud vars, entire coverage, 1-hr avg
netCDF File Header Description (Data Object Design File) - ecmwfvar - ECMWF: model met. and cloud variables at altitude, entire coverage, 1-hr avg
netCDF File Header Description (Data Object Design File)
Measurement Description
- sssecmwf[xxx]flxX1.c1
-
These files contain the radiative fluxes throughout the atmosphere.
The fluxes are averages over the last hour.
They are archived on the so called flux levels of the model (often referred to as half-levels). The full levels on which the variables are stored are placed between two flux levels. Hence, the largest level number represents the surface and level 1 the top of the atmosphere. Full level k is between half level k and k+1.- net shortwave flux (W/m^2)
- net longwave flux (W/m^2)
- sssecmwf[xxx]sfcX1.c1 (through 2000-09-12)
-
These files contain surface variables and fluxes. The level number is set
to 1.
The measurements are:
- soil temperature in layer 1 (7 cm deep) (K) **
- shortwave radiation (W/m^2)
- longwave radiation (W/m^2)
- latent heat flux over water (W/m^2) **
- latent heat flux over ice/snow (W/m^2) **
- sensible heat flux (W/m^2)
- ground heat flux between layer 1 and layers 2/3/4 (W/m^2) **
- soil moisture in layer 1 (m^3/m^3) **
- large-scale rain (mm/s)
- convective rain (mm/s)
- large-scale snow (mm/s)
- convective snow (mm/s)
- surface pressure (Pa)
- turbulent moisture flux kg/kg * kg/(m^2*s)) ++
++ measurement in twp files; no longer contained in new data stream immediately following. - Note the following two data streams replace sssecmwf[xxx]sfcX1.c1 beginning 2000-09-13)
-
The change in datastreams and measurements are a direct result of
changes in the land-surface parametrization which became operational
for the forecast starting 2000-09-12. The surface, "sfc",
data was split into two types of files - sfc1l and sfcml. "1l" stands
for 1 layer and is available for all sites. "ml" stands for multi-level
and are only available for sites which are considered land in the model
(SGP and NSA and Darwin (DAR) for TWP also the mobile facilities PYE,
NIM, FKB, HFE).
- sssecmwf[xxx]sfc1lX1.c1 (beginning 2000-09-13)
-
This data stream contains the same measurements as sssecmwf[xxx]sfcX1.c1
which it replaces with the exceptions noted above. The new data stream
also contains consistent measurement names across all the sites. The surface
level for the TWP sites is now 1; in the older version of these files, it
was set to 61.
The measurements that are carried forward are:
- shortwave radiation (W/m^2)
- longwave radiation (W/m^2)
- sensible heat flux (W/m^2)
- large-scale rain (mm/s)
- convective rain (mm/s)
- large-scale snow (mm/s)
- convective snow (mm/s)
- surface pressure (Pa)
- surface latent heat flux (W/m^2)
- sssecmwf[xxx]sfcmlX1.c1 (beginning 2000-09-13)
-
These measurements are all multilevel at 4 levels
as represented in the ECMWF land-surface parametrization.
The soil model layers have the following depths starting
from the top layer (layer 1 in the files):
- 7 cm
- 21 cm
- 72 cm
- 189 cm
- soil temperature (K)
- heat flux at layer bottom (W/m^2)
- moisture flux at layer bottom (kg/(m^2*s))
- soil wetness (kg/m^2)
- sssecmwf[xxx]tenX1.c1
-
These files contain the total and physical tendencies for u,v,T and q on
the model levels. The units are as in the sssecmwf[xxx]varX1.c1 files
but per second.
The tendencies are:
- u total (m/s/s)
- u physics (m/s/s)
- v total (m/s/s)
- v physics (m/s/s)
- T total (K/s)
- T physics (K/s)
- q total (kg/kg/s)
- q physics (kg/kg/s)
- sssecmwf[xxx]varX1.c1
-
These files contain the model variables on each model level. Level 1
is the top full level of the model (10 hPa). The level with the highest
number is the lowest altitude full level.
The measurements include:
- p - pressure (Pa)
- u - zonal wind component (m/s)
- v - meridional wind component (m/s)
- T - temperature (K)
- q - specific humidity (kg/kg)
- l - specific cloud liquid water content (kg/kg)
- i - specific cloud ice content (kg/kg)
- a - cloud fraction (percent/100.)
- R - relative humidity (percent/100.)
- w - omega=vertical velocity in pressure coordinates (Pa/s)
- sssecmwf[xxx]sfceX1.c1 (beginning January 1998)
-
These files contain extra near surface and surface variables including:
- 2m Temperature (K)
- 2m specific humidity (kg/kg)
- 10m wind u-component (m/s)
- 10m wind v-component (m/s)
- skin temperature (K)
- albedo
- downward surface solar radiation (W/m^2)
- downward surface longwave radiation (W/m^2)
Temporal Coverage
Site | Begin Date/End Date |
---|---|
NSA | 1997-09 |
SGP IOPs | 1995-04-17/05-07, 1995-07-17/08-14, 1995-09-22/11-01, 1996-04-01/04-30, 1996-05-01/05-10, 1996-07-15/08-05 |
SGP | 1996-08 |
TWP Darwin | 2002-03-20 |
TWP Manus | 1997-06 |
TWP Nauru | 1999-01 |
NIM | 2005-05-05/2007-03-27 |
PYE | 2005-04-20/2005-10-21 |
FKB | 2007-04-01/2008-02-29 |
HFE | 2008-05-01/2009-??-?? |
These diagnostic files are available at the ARM Archive with an approximately one month delay.
Area Covered
SGP
There are three SGP domains over which all the quantities are averaged.They are numbered 27,28,29. The areas for those domains are:
point number | Longitude upper left | Latitude upper left | Longitude lower right | Latitude lower right | comment |
---|---|---|---|---|---|
27: | 260.3 | 38.8 | 264.6 | 34.8 | |
28: | 261.7 | 34.8 | 263. | 34.2 | (eliminated 2002-03-20) |
29: | 261.7 | 37. | 263. | 36. |
NSA
The NSA diagnostic data are available for two single points (numbered 13 and 19)
located at:
point number | Longitude | Latitude | Comment |
---|---|---|---|
13: | 202.00 | 70.41 | (beginning 2002-03-20) |
19: | 203.20 | 71.05 | (before 2000-11-22) |
19: | 204.00 | 71.12 | (beginning 2000-11-22) |
TWP DAR
There are three single points representing TWP Darwin. These data begin on
2002-03-20. Other domains in SGP, TWP Manus and TWP Nauru were eliminated
to make room for these new points and for the new NSA point.
The Darwin points are number 6, 28 and 50. The points are:
point number | Longitude | Latitude |
---|---|---|
6: | 130.43 | -12.82 |
28: | 129.73 | -12.47 |
50: | 131.13 | -13.52 |
TWP MAN
There are three TWP Manus domains over which all the quantities are averaged.
They are numbered 48,49,50. The areas for those domains are:
point number | Longitude | Latitude | Comment |
---|---|---|---|
48: | 147.30 | -1.93 | (before 2000-11-22) |
48: | 147.37 | -1.97 | (beginning 2000-11-22) |
point number | Longitude upper left | Latitude upper left | Longitude lower right | Latitude lower right | comment |
---|---|---|---|---|---|
49: | 146.60 | -1.10 | 148.10 | -2.80 | |
50: | 146.00 | -0.60 | 148.80 | -3.30 | (eliminated 2002-03-20) |
TWP NAU
There are three domains for the TWP Nauru diagnostic data.
They are numbered 4, 5, 6.
The areas for those domains are:
point number | Longitude | Latitude | Comment |
---|---|---|---|
4: | 167.06 | -0.28 | (before 2000-11-22) |
4: | 167.99 | -0.53 | (beginning 2000-11-22) |
point number | Longitude upper left | Latitude upper left | Longitude lower right | Latitude lower right | comment |
---|---|---|---|---|---|
5: | 166.10 | 0.30 | 167.70 | -1.30 | |
6: | 165.50 | 0.90 | 168.30 | -1.90 | (eliminated 2002-03-20) |
The Manus and Nauru areas in the ECMWF model are all model sea points.
AMF PYE 2005
The Point Reyes diagnostic domain consists of two single points:point number | Longitude | Latitude |
---|---|---|
18 | 237.08 | 38.11 |
23 | 236.67 | 38.11 |
AMF NIM 2006
The Niamey diagnostic data domain consists of a single pointpoint number | Longitude | Latitude |
---|---|---|
76 | 2.46 | 13.52 |
AMF FKB 2007
The Black Forest diagnostic data domain consists of 3 COPS super-site locations:point number | Longitude | Latitude | Nearest Supersite |
---|---|---|---|
115 | 8.32 | 48.46 | Supersite M, ARM AMF Murgtal, Heselbach: 8.405°E, 48.545°N, ca. 500 m |
116 | 8.67 | 48.68 | Supersite S, Gliders Airport Deckenpfronn, 8.813°E, 48.635°N, ca. 600 m |
117 | 7.67 | 48.68 | Location POLDIRAD, Waltenheim sur Zorn 7.610°E, 48.739°N, ca. 120 m |
AMF HFE 2008
The China diagnostic data domain consists of 4 COPS super-site locations:point number | Longitude | Latitude | Nearest Supersite |
---|---|---|---|
14 | 120.25 | 31.37 | ARM AMF Taihu: 120.22°E, 31.42°N, ca. 7 m |
15 | 117.00 | 39.69 | ARM AMF Xianghe: 116.96°E, 39.75°N, ca. 36 m |
115 | 116.75 | 32.49 | ARM AMF Shouxian: 116.78°E, 32.56°N, ca. 23 m |
116 | 100.69 | 39.01 | ARM AMF Zhanghe, 100.58°E, 38.93°N, ca. 1483 m |
Data Stream Inputs
fkbecmwfX1.00
hfeecmwfX1.00
nimecmwfX1.00
nsaecmwfX1.00
pyeecmwfX1.00
sgpecmwfX1.00
twpecmwfX1.00
twpecmwfdarX1.00
twpecmwfnauX1.00
Notification Form Link
Contacts
- ARM Mentor Shaocheng Xie
- ARM Software Developer Laurie Gregory
FAQ
- Q: The old twpecmwf[xxx]sfcX1.c1 (pre 2000-09-13) files had "turbulent moisture flux". Does this match to anything in the new files (or to anything in SGP/NSA)?
- A: (from Christian Jacob, ECMWF): "Yes and no. Due to the backing out procedure we had to apply for the TWP sites, we did not have the surface latent heat flux at those sites and replaced it by the moisture flux (which can be converted into the former). Now that we cleaned up the mess, we do have surface latent heat flux instead, which is cleaner. Again, it comes in different units and is therefore not a direct replacement, although it contains the same information."
- Q: Often soil wetness in a generic sense is expressed in terms of (volumetric) soil moisture content, which is unitless or has units of m^3/m^3. For example, a corresponding old term was "soil moisture in layer 1 (m^3/m^3) (soil_moisture in sgp and nsa)." The new "soil wetness" seems to represent the amount of water integrated with depth for each layer. Can someone confirm that this interpretation is correct?
- A: The interpretation of soil wetness in the question is correct.
- Q: Is the model elevation at Barrow 8 m?
- A: No, it is 5 m.
- Q: Is there any information on model ozone available?
- A: No, there is no information on ozone in any of these products.
- Q: Are the variables in the diagnostic files to be interpreted as hourly averages for the hour prior to the time-stamp?
- A: From Martin Köhler at ECMWF: Yes and No! The answer depends on the type of variable:
for fluxes and tendencies: average over previous hour before time stamp (e.g. latent heat flux)
other variables: instantaneous value at time stamp (e.g. T2m or cloud cover)
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"
- Why single data points moved in diagnostic ECMWF files
- To generate point data in the diagnostic files, ECMWF specifies to the model the lat-lon of the observation point, and get as an output the nearest model point. When the model grid changes (such as on 2000-11-22, where the model resolution increased from ~60 km to ~40 km), the location of the nearest model point changed.
- Discussion from Christian Jacob on changes to diagnostic files on 2000-09-13.
- In June 2000 we introduced a new land surface parametrization scheme into
our model. We immediately realised that the diagnostic tool that we are using
(amongst many other applications) to get out the data for the ARM sites was
totally inadequate for the new scheme. This, together with some things we did
not like even for the old parametrization scheme, led us to invest some time to
completely rewrite the surface part of this diagnostic tool. The changes that
you see are repercussions of this rewrite. The rewritten diagnostics became
operational on 2000-09-12, hence affecting ARM data from 2000-09-13
onwards.
To give you an example of the sort of changes: The old diagnostic tool did not provide any direct information at the surface over sea points in the model. It so happens that Manus and Nauru are way too small islands to be land points even in our highest of model resolutions. Therefore, we had to play all sorts of tricks to back out things like surface fluxes from other parts of the archive. That is the reason why you had different files for the TWP sites in the past. Obviously, since we rewrote the software anyway, we wanted to get rid of that problem, and we did. Hence, now all the files are exactly the same. The only difference is that you have extra files at the locations that are really land in the model (SGP and NSA), that deal with real land parameters, such as soil temperature and soil moisture, which obviously don't exist at sea points.
The difference in measurement names between old and new are also due to the cleanup.
Acronyms
ECMWF European Centre for Medium Range Forecasts GRIB GRIdded Binary