(Last update June 10, 2004 / Markku Kangas)             Back to main page            Mast verification page

Plots show comparison of mast measurements with weather model forecasts. Presently, left frame contain forecasts from the operational Hirlam (RCR) model run by FMI and Arpege model of Meteo France. Plot legends for the forecasts are of the form "XXX m/nn", where XXX denotes the model, m is model run time as days from present day midnight, and nn is the run hour. Measurements are denoted with abbreviation OBS.

The time interval in the plots spans 2.5 -3 days, starting from 2 days backwards from present day midnight and reaching as far as data is available. First 24 hours from 00 and 12 forecasts are plotted. The plotting takes place with 1-2 hour intervals. With other masts than Sodankylä, the measurements cover only the two previous days. These other masts are plotted for Sodankylä only.

The actual measurement heights vary somewhat with masts, whic must be considered when looking at the plots. At the top of each picture, there is a legend showing the measurement heights. Also the parameters plotted in the graphs vary; from other masts than Sodankylä, only temperatures, relative humidity and wind speed are available.

PICTURES

Temperature 1
Temperature at the lowest level in the mast compared to model 2m ("screen height") temperature.

Temperature 2
Temperature at a higher level in the mast compared to lowest model level temperature. In ARPEGE plots, produced as by a linear interpolation between the two last levels (heights about 16m and 62 m).

Temperature difference
Difference between temperatures 1 and 2, an indicator of the surface inversion.

Relative humidity
Relative humidity at the lowest level in the mast compared to model 2m ("screen height") relative humidity.. 

Wind speed
Wind speed in the mast compared to forecast 10 m wind speed. In Kivenlahti plots, the second observation line ("OBS Corr") shows roughly corrected observation (correction based on measurements made with a new measurement device).

Global radiation
Solar shortwave (global) radiation DOWNwards in the mast compared to forecast surface radiation.

Long wave radiation upwards
Long wave radiation UPwards measured in the mast compared to the forecast. In HIRLAM plots, the radiation is calculated from downward and net long wave radiation.

Sensible heat flux
Sensible heat flux UPwards measured in the mast compared to the forecast.

Latent heat flux
Latent heat flux UPwards measured in the mast compared to the forecast.

Evaporation
Evaporation nmeasured in the mast compared to the forecast.

Mmomentum flux
Momentum flux in the mast compared to the forecast.