FINLAND
FINNISH METEOROLOGICAL INSTITUTE
Helsinki
This report describes the essential features of the operational numerical weather prediction (NWP) system during the year 2000. The system is based on the use of the results from the international Hirlam project. The other countries, in addition to Finland, in this project are Sweden, Norway, Denmark, Iceland, Ireland, France, Spain and the Netherlands. Meteorologically the system is based on the HIRLAM reference system version 4.6.2.
The operational numerical forecasting system at the Finnish Meteorological Institute (FMI) contains two suites. The "Atlantic suite" (ATA) contains a complete data-assimilation/forecasting system. It is run to +54 hours four times a day, based on 00, 06, 12 and 18 UTC data. The resolution is 0.4
° x 0.4° in the horizontal and 31 levels in the vertical. The geographical area covers Europe, North Atlantic and parts of North America. Forecasts received from ECMWF are used for lateral boundary values in the Atlantic suite.The integration area of the other suite (called ENO) covers mainly the northern Europe. It contains a full data assimilation/forecast system and uses boundary values from the ATA suite with a frequency of three hours. The resolution is 0.2
° in the horizontal and there are 31 levels in the vertical. The forecast length is 54 hours.The T3E and Origin 2000 supercomputers, hosted by the Center for Scientific Computing (CSC), are used in the HIRLAM system.
2. Equipment in use for numerical forecasting in Finland
Cray T3E system is the main computer used for numerical weather prediction. Cray T3E is a distributed memory parallel computer. The hardware consists of 512 RISC processors for parallel use. Each processor has 128 MB of main storage capacity. The Origin 2000 system is used as a backup system. In the HIRLAM application on Cray T3E 40 processors during the analysis and 128 processors during the forecast are used.
At the Finnish Meteorological Institute the computer configuration of the operational system contains mainly UNIX and Linux workstations and servers.
3. Data and products from GTS used in NWP
Typical number of observations used daily in the ATA suite:
SYNOP, SHIP: 19000
TEMP: 300
AIREP: 800
PILOT: 70
DRIBU: 1100
SATOB: 800
SATEM 300
4. Data input system
Automated
5. Quality control system
Format is checked before transmission to the GTS
6. Monitoring of the observing system
Surface and upper air observations are monitored on the national level.
7. Forecasting system
7.1 System run schedule
The HIRLAM level 4.6.2 system is used for short range, 1-2 days, forecasting. Two versions of the HIRLAM forecasting system is run operationally:
- the "Atlantic suite" (ATA): full 6 hour data assimilation cycle four times a day, resolution 0.4
° in the horizontal and 31 levels in the vertical, forecast length 54 hours, products available with the interval of one hour- the "European suite" (ENO): full 6 hour data assimilation cycle four times a day, resolution 0.2
° in the horizontal and 31 levels in the vertical, forecast length 48 hours, products available with the interval of one hour7.2 The ATA forecasting system
Four complete data assimilation cycles are run daily with the HIRLAM system to +54 hours. The cut-off time for observations is 2 h 30 min. The elapsed time of one complete forecast run (including analysis, forecast and post-processing) is about 45 min.
7.2.1 Data assimilation, objective analysis and initialisation
Analysis system:
3-dimensional multivariate statistical interpolation, univariate for relative humidity (limited area version of the ECMWF scheme)
A separate univariate analysis for sea surface temperature, ice coverage and snow depth
Parameters:
surface pressure, geopotential, wind components, relative humidity, sea surface temperature, ice coverage and snow depth
Levels:
hybrid levels defined by A’s and B’s. Levels are (assuming the surface pressure of 1000 hPa): 996, 983, 959, 928, 891, 850, 807, 762, 717, 671, 626, 581, 538, 495, 453, 413, 374, 338, 302, 269, 237, 208, 181, 156, 132, 111, 90, 70, 50, 30, 10 hPa
Observation types:
TEMP, PILOT, SYNOP, SHIP, BUOY, SATOB and AIREP
First guess:
six hour forecast of the previous cycle
Initialisation:
adiabatic non-linear normal mode initialisation, 4 vertical modes are initialised
Cut-off time:
2 h 30 min.
7.2.2 Model
Basic equations:
primitive equations in flux form
Independent variables:
l ,q
Dependent variables:
T, u, v, q, p
Integration domain:
194 * 140 gridpoints in transformed latitude-longitude grid, 31 vertical levels (as in the analysis)
Grid length:
0.4
Grid:
staggered grid (Arakawa C)
Time-integration:
leapfrog semi-implicit (
Orography:
smoothed US Navy mean orography, no gravity wave drag
Physical parameterisation:
prognostic cloud scheme
turbulence based on turbulent kinetic energy
Hirlam radiation scheme
Hirlam old surface parameterisation scheme
Horizontal diffusion:
implicit fourth order
Boundaries:
time dependent lateral boundary conditions from ECMWF 00 and 12 UTC forecasts (on model levels)
The integration area covers Europe, the North Atlantic and north-eastern part of Canada. It is a transformed latitude/longitude grid with the north pole moved along the 180
° meridian to the latitude of 30° N to avoid the convergence of longitudes towards the pole.7.2.3 Availability of the numerical weather prediction products
All the HIRLAM products on model and constant pressure levels are available are for applications in the real-time data base with the frequency of one hour.
HIRLAM forecasts are available to duty forecasters on workstations. The geopotential, temperature, relative humidity and three dimensional wind fields are available on constant pressure levels (1000, 925, 850, 700, 500, 400, 300 and 250 hPa). In addition, surface pressure, 10-metre wind, 2-metre temperature, intensity of precipitation and accumulated large-scale and convective precipitation, surface fluxes of sensible and latent heat and net radiation are available. Also several derived parameters such as type of precipitation, stability index, fog, cloudiness etc. are computed from every forecast.
Nearest gridpoint values are picked up to produce forecasted vertical soundings of temperature, dewpoint deficit and wind at selected points.
Hirlam forecasts are used as input in the real-time trajectory model, air pollution models, cloud animations and in the interpretation models of the satellite data and UV-index forecasts. In addition, Hirlam products are used in many other applications.
7.3 The ENO forecasting system
The mesoscale system is run four times a day to 54 hours. The main difference to the basic system is the horizontal gridlength, which in the ENO suite is system is 0.2
°. This forecast suite is run partly in parallel, partly after the ATA HIRLAM run mentioned in the previous chapter.7.3.1 Data assimilation, objective analysis and initialisation
Same as in 7.2.1 with some minor modifications
7.3.2 Model:
Same as in 7.2.2 with the following exceptions:
Grid length:
0.2
Time-integration:
leapfrog semi-implicit (
Boundaries:
boundary values are interpolated horizontally and vertically from the forecasts of the ATA suite. Boundaries are updated every three hours
7.3.3 Numerical weather prediction products
The same fields are available to forecasters as from the ATA suite.
8. Verification of prognostic products
Due to the limited computational area of the operational forecast model, no verification summaries are computed for the areas suggested. However, standardised verification scores are being provided operationally for internal purposes.
9. Plans for the year 2000
Several update are foreseen in the 2000
10. References and other publications
Heikinheimo M., M. Kangas, T. Tourula, A. Venäläinen, S. Tattari, 2000: Momentum and heat fluxes over lakes Tämnaren and Råksjö based on measurements by the bulk aerodynamic and eddy-correlation methods. Agricultural and Forest Meteorology, Vol. 98-99 (1999), NOPEX Special Issue, pp. 521-534.
Lindskog, M., Järvinen, H. and D.B. Michelson, 2000: Assimilation of Radar Radial Winds in the HIRLAM 3D-Var. Phys. Chem. Earth (B), 25,1243-1249.
Rabier F., Järvinen H., Klinker E., Mahfouf J-F and A. Simmons, 2000: The ECMWF implementation of four dimensional variational assimilation. Part I: Experimental results with simplified physics. Q.J.R. Meteor. Soc., 126, 1143-1170.
Savijärvi H. and Järvenoja S., 2000: Aspects of the Fine-Scale Climatology over Lake Tanganyika as Resolved by a Mesoscale Model. Meterol.Atmos.Phys., 73, 77-88.
Eerola, K. and Järvenoja, S., 2000: Limited Area Modelling at the Finnish Meteorological Institute in 1999. EWGLAM Newsletter, No 29, 58-63.
Tuomenvirta, H., Venäläinen, A., Juottonen, A. and Haapala, J., 2000: The impact of climate change on the Baltic Sea Ice and soil frost beneath snow-free surfaces in Finland. Publications of Ministry of Transport and Communications 13/2000, 56 p.
Rontu L.,2000: HIRLAM and mountains. In: The 22nd Nordic Meteorologists' Meeting. Marienhamn, 27.6-1.7.2000.
Unden P., Cats G., Rodriguez E. and Järvinen H., 2000: The HIRLAM-5 Project. In: The 22nd Nordic Meteorologists' Meeting. Marienhamn, 27.6-1.7.2000.
Venäläinen, A., Tuomenvirta, H., Heikinheimo, M., Kellomäki, S., Peltola, H., Strandman, H. and Väisänen H., 2000: Influence of climate warming on soil frost in Finland based on model-data from Sweclim. In: Iversen, T. and Hoiskar, A.K., (Ed.), Reg Clim General Technical report No. 4, Presentations from Workshop 8-9 May 2000 at Jevnaker, Norway. Available from: Norwegian Institute for Air Research.
Venäläinen, A., 2000: Road salting estimation based on wintertime air temperature. 1st PNS Snow Conference, Kelowna, British Columbia at The Grand Okanagan Resort and Conference Centre, June 12th - 14th, 2000.
Eerola, K., 2000: Advances in the HIRLAM model. CSC News,Vol.12, No 1,9-11.
Eerola, K., 2000: The new operational HIRLAM at the Finnish Meteorological Institute. Hirlam Newsletter No 35, p. 36-43.
Eerola, K., 2000: Some views of Fortran 90 and Hirlam., Hirlam Newsletter No 35, p. 199-207.
Fortelius, C., 2000: Status of the HIRLAM delayed mode data assimilation for Baltex Bridge. Hirlam Newsletter No 35, p. 193-198.
Järvenoja, S. and L. Rontu, 2000: Testing the revised HIRLAM radiation scheme. Hirlam Newsletter No 35, p. 171-179.
Järvenoja, S., 2000: Missing snow cover in the HIRLAM system in winter - A catastrophe or not? Hirlam Newsletter No 35, p. 149-156.
Eerola, K., 2000: Updates for the list of suspicious sounding stations Hirlam Newsletter No 36, p. 20-24.
Fortelius, C., 2000: Anomalous evaporation in arid regions. Hirlam Newsletter No 36, p. 30-31.
Järvenoja, S., 2000: Problems in the operational HIRLAM at FMI in spring and summer 2000. Hirlam Newsletter No 36, p. 68-79.
Rontu, L. and C. Fortelius, 2000: Recent developments in postprocessing. Hirlam Newsletter No 36, p. 80-88.
Bister, M., 2001: Effect of peripheral convection on tropical cyclone formation. J. Atmos. Sci., Accepted with revisions.
S.M. Joffre, M. Kangas, M. Heikinheimo, and S.A. Kitaigorodskii: Variability of the atmospheric boundary layer height during the WINTEX experiment. Submitted to Boundary Layer Research.
M. Kangas, M. Heikinheimo, and V. Laine: Accuracy of NOAA AVHRR-based surface reflectances over winter-time boreal surface - comparison with aircraft measurements and land-cover information. Accepted for publication in Theoretical and Applied Meteorology.
Venäläinen, A., Estimation of road salt use based on wintertime air temperature. Accepted for publication in Meteorological Applications.
Venäläinen, A., Tuomenvirta, H., Lahtinen, R. and Heikinheimo, M., The influence of climate warming on soil frost in case of snow-free surfaces in Finland. Accepted for publication in Climatic Change.
Venäläinen, A., Tuomenvirta, H., Heikinheimo, M., Kellomäki, S., Peltola, H., Strandman, H. and Väisänen, H., 2000. The impact of climate change on soil frost under snow cover in a forested landscape. Accepted for publication in Climate Research.