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Access is provided for research and education through
a simple electronic registration process, with valid e-
mail address and acknowledgment of conditions of
supply. Under the simple registration process, access is
given with a 48-hour delay after the initial time of the
forecast. Real-time access is granted in some cases, for
example for field experiments and projects of special
interest to Thorpex. Registration for real-time access is
handled via the Thorpex intellectual property office.
Data access is operated via the TIGGE data portals.
Currently these are at NCAR and ECMWF,3 with the CMA
portal due to open later in 2007. The data portals can
currently be used for registration; search, discover and down-
load of files; selection of data by initialization date/time, data
provider, file type and forecast time; checking volume and
downloading data. Both portals also provide a selection of
parameter subsets. ECMWF offers grid interpolation and a
limited amount of spatial subsetting, while NCAR plans to
offer these expanded services in the future.
Outlook
It is anticipated that limited-area ensemble prediction
systems will also form an important component of GIFS,
whose development is dependent upon TIGGE. The
priority requirement here is to develop standard formats
enhancing the interoperability of the existing systems.
A key objective is to facilitate the use of lateral bound-
ary conditions from global systems by various
limited-area systems. A panel of experts called TIGGE-
LAM has recently been set-up to organize the
limited-area-model component of TIGGE.
turn, lead to targeted applications reducing societal risk to severe weather
through better forecasts (for example health, energy, flood warning, fire
weather). The hydrological community (e.g. through the Hydrologic
Ensemble Prediction Experiment or HEPEX) is expected to be a strong
user of TIGGE data. Some by-products of TIGGE have already appeared,
for instance, the acceleration in implementing various components of the
newWMO information system such as Gridded Binary (GRIB)
2
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TIGGE technical solutions
The data exchange technique is based on the Internet Data
Distribution/Local DataManager fromUnidata. The newWMO standard
GRIB2 for gridded data was agreed by all partners to support data
exchanges between data providers and archiving centres. The database is
composed of GRIB2 records. The units, names of the various fields, accu-
mulation periods, etc. are identical for all data providers. The data
providers supply data on grids of their own choosing, which are as close
as possible to the native grid employed to carry out the predictions. The
data are archived on the same grid as received. Data providers must ensure
that appropriate software is available to the archiving centres to enable
users to interpolate data to latitude/longitude grids and locations of their
choosing. They must also ensure that when revisions to their systems are
made, revised interpolation software is communicated to the archiving
centres immediately. The archiving centres maintain a user-friendly inter-
face based on interpolation software supplied by the data providers. This
allows the TIGGE users to retrieve data easily at single points or on regular
latitude-longitude grids of their own choosing. Special effort will bemade
to provide quick access to long series of data at a single point, as this is a
frequent request for many applications. Automatic regular requests will
also be possible. In Phase-1, each archive centre provides data through its
own proprietary user interface. However, the supplied data are of course
the same. In Phase-2, the user interface will be unified.
Current status of the TIGGE database
A complete list of data requested from the data providers can be found
at the TIGGE Internet site.2 The data from operational global ensem-
ble forecasts are divided into fields in pressure levels and single-level
fields. Pressure level fields comprise geopotential, temperature, specific
humidity and wind components at 1,000, 925, 850, 700, 500, 300, 250,
and 200 hPa. Additional fields at the tropopause level reflect potential
vorticity on the 320K potential temperature surface, and potential
temperature and wind on the 2PVU potential vorticity level. Other
single-level fields are listed in the table.
Currently five providers (ECMWF, NCEP, UK Met Office, JMA and
CMA) are delivering data, with initial dates varying from Autumn 2006
to Spring 2007. Pressure level data are available from all five providers,
with very few exceptions. Combined streamlines from the five providers
can convey a complete picture of the forecast uncertainty. Production
of single-level fields has proven to be a tough challenge and availabil-
ity varies widely between providers. However, the more useful
single-level fields (such as the description of basic weather parameters
at the surface) are available from all five providers. A detailed list of
available data can be found from the data portals.
Five additional data providers (CPTEC, KMA, MSC, BMRC, and
Météo-France) have signed to the project and should start providing
data before the end of 2007.
Access to TIGGE data for research and education
Data providers supply their products to the TIGGE archive centres
under an agreed set of rules, which include redistribution rights.
Single level fields in the TIGGE database
10 meter u-velocity
10 meter v-velocity
Convective available potential energy
Convective inhibition
Field capacity
Land-sea mask
Mean sea level pressure
Orography
Skin temperature
Snow depth water equivalent
Snow fall water equivalent
Soil moisture
Soil temperature
Sunshine duration
Surface air dew point temperature
Surface air maximum temperature
Surface air minimum temperature
Surface air temperature
Surface pressure
Time-integrated outgoing long wave radiation
Time-integrated surface latent heat flux
Time-integrated surface net solar radiation
Time-integrated surface net thermal radiation
Time-integrated surface sensible heat flux
Total cloud cover
Total column water
Total precipitation
Wilting point
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OCIETAL
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ENEFIT
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EATHER