Lateral and Boundary Data in RC LACE Countries


Lateral and Boundary Data (LBC data) are one of the neded component for LAM forecast.
During the common Operational suite in Prague LBC data from global model ARPEGE were transfered to Prague. First, via EQUANT lines (till the begining of year 2000) and after that via RMDCN lines. With the end of common Operatinal suite almost all ALADIN centres in LACE community start with retrieving of LBC data from global model ARPEGE on LACE domain.
Characteristics of LACE coupling domain from global model ARPEGE:
    - resolution 20.7 km,
    - size of domain 139x124 (150x135) points,
    - corners SW(1.83,33.67), NE(39.79,55.78).
Regarding the telecommunication access two options of retrieving data are possible:
    - by satellite receivers via RETIM 2000 system 128 kbps (in some countries start in March 2003),
    - by line access to Toulouse (RMDCN lines, Internet lines, ISDN lines, ... ).

During the common Operational suite all RC LACE partners retrieved high-resolution LBC data from Prague for their domains, this high-resolution LBC data was part of the LACE domain.
Characteristics of high-resolution LACE coupling domain:
    - resolution 12.2 km,
    - size of domain 133x97 (144x108) points,
    - corners SW(5.66,41.15), NE(26.56,51.90).

Curent status with Retrieval of data in RC LACE Countries:
    - in Austria via Internet and RETIM 2000,
    - in Croatia via Internet and RETIM 2000,
    - in Czech Republic via RMDCN and testing of Internet connection in progres,
    - in Hungary via RETIM 2000 and backup is Internet,
    - in Slovakia via EQUANT from Austria and LACE coupling domain via RETIM 2000 and
    - in Slovenia via Internet.


Planed modification of ARPEGE cut-offs and ALADIN LBC dissemination

Current situation of LBC provision schedule:

Run
UTC		 Assimilation
Window
UTC		 Cut-off
UTC		 LBC available
UTC		 LBC available
Summer
Local time		 LBC available
Winter
Local time
00 21-03 01:30 02:30 - 03:00 04:30 - 05:00 03:30 - 04:00
06 03-09   09:30 - 10:00 11:30 - 12:00 10:30 - 11:00
12 09-15 13:30 14:30 - 15:00 16:30 - 17:00 15:30 - 16:00
18 15-21   21:30 - 22:00 23:30 - 00:00 22:30 - 23:00


The planned new set-up of LBC provision schedule:

Run
UTC		 Assimilation
Window
UTC		 Cut-off
Summer
UTC		 Cut-off
Winter
UTC		 LBC
Summer
UTC		 LBC
Winter
UTC		 LBC
Summer&Winter
Local time
00 21-04 03:30 04:30 04:30 - 05:00 05:30 - 06:00 06:30 - 07:00
06 03-10 10:30 11:30 11:00 - 11:30 12:00 - 12:30 13:00 - 13:30
12 09-16 15:30 16:30 16:00 - 16:30 17:00 - 17:30 18:00 - 18:30
18 15-01 00:30 01:30 01:00 - 01:30 02:00 - 02:30 03:00 - 03:30


The new set-up is under test, it is planned to keep 4 long cut-off runs per day. The tuning for each run will be different because of the asymmetry and different lengths of the assimilation window.
The shift in UTC between summer and winter is found annoying by the partners.
There was a proposal for a test: for the 18 UTC run to have another surface analysis at 00 UTC at the end of the assimilation window. The question whether the second refreshment of the surface data may be useful should be looked up at GMAP.

Resolution of LSC

The committee authorised Project Leader to inform Météo-France contact point about the requirements for the new dissemination. It was agreed to ask for LBC files up to 60 hours with 3 hour frequency from four production runs per day (0h, 6h, 12h and 18h UTC). The tests should be performed regarding the required set-up for several cases. The implementation should be announced one month ahead.


Back to RC LACE home Last change: 2004-01-13