Notes

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Outline

Some Results of Verification of LM against Observations
| Hellenic National Meteorological Service
| George Galanis
| E-mail: galan@hnms.gr
Abstract.
LM in Greece
Stations under study :
Athens’ Temperature (06 UTC) June – August
Athens’ Temperature (12 UTC) June – August
Thessaloniki’s Temperature (06 UTC) June – August
Heraklion Temperature (18 UTC) June – August
Kozani’s Temperature (12 UTC) June – August
Time Period: June – August 2001
| We encountered significant systematic errors, especially at near coast locations during the evening hours.
| Main reason: Some of the grid points used in the relevant interpolation schemes have totally different characteristics from the area in study (e.g. lay over the sea).
| The Kalman filtering used gives excellent results towards the improvement of the final forecast, since it :
| - eliminates the systematic error
| - decreases the standard deviation of the absolute error
Athens’ Temperature (18 UTC) February – April
Athens’ Temperature (12 UTC) February – April
Thessaloniki’s Temperature (06 UTC) March – April
Heraklion Temperature (18 UTC) February – April
Time Period: February – April 2001
| The systematic error in the time series of this period is seriously decreased compared to the relevant of summer months
| The proposed Kalman filter keeps giving serious help towards the elimination of this error.
Thessaloniki’s Wind’s Speed (06 UTC) June – August
Athens’ Wind Speed (12 UTC) June – August
Santorini’s Wind Speed (12 UTC) June – August
Heraklion Wind’s Speed (18 UTC) June – August
Verification of Wind’s speed Time Period: June – August 2001
| The direct outputs of LM do not encounter serious systematic errors.
| In those cases where, even slightly, errors emerge, Kalman filter improves the final results.