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Finnish Icing Atlas. Karoliina Ljungberg Research Scientist Finnish Meteorological Institute. Background. Finnish Government’s new energy strategy 6 TWh of wind power till 2020 (~2000 MW) Installed 144 MW by the end of 2009 Wind Atlas 2009 Ministry of Employment and the Economy
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Finnish Icing Atlas Karoliina Ljungberg Research Scientist Finnish Meteorological Institute
Background • Finnish Government’s new energy strategy • 6 TWh of wind power till 2020 (~2000 MW) • Installed 144 MW by the end of 2009 • Wind Atlas 2009 • Ministry of Employment and the Economy • Wind resource and wind power production maps • Representative 4 years • Statistically chosen among the past 50 years
Motivation to create Icing Atlas • Northern location of Finland • Between 60 – 70 °N • Duration of winter: • in Lapland > 6 months • in Åland ~ 4 months. • Best possible placing of wind farms. • To avoid ice accretion • Help for planning at new sites • Older icing maps based on mast measurements (~ 10 – 20 mast’s) • Long coastline and complex archipelago and terrain
Methods: AROME mesoscale model • Horizontal resolution 2.5km • 40 levels from which 8 at lowest 1000m • 3h interval • Meteorological parameters: • Temp • Wind • cloud ice • cloud water • Rain • Snow • graupel
Methods: Icing model • Physic based on Standard ISO12494 • Icing rate [g/h]: a1= collision efficiency a2= sticking efficiency a3= accretion efficiency w = mass concentration of particles
Model verification Example: • Icing observations are not part of FMI's daily measurements. • Observations still available from field campaigns • On-off measurements • Ice mass measurements
Model verification • AROME is used operationally at FMI’s weather service • AROME model verified by using all available observations • ground observations, soundings, satellite data • Winds and temperature are modeled well • Main source of error is caused by cloud microphysics • Division to hydrometeors • Spatial and temporal resolution of clouds • AROME handles clouds within its own resolution However, we don’t think that this causes significant errors, because of averaging four years of model data
Results • Icing Atlas • Maps for levels: 50m, 100m, 200m • Intensity of icing [10g/hour] • Frequency of icing • Results responded to our expectations • Coastal areas • Higher and fell areas • Results will be published online by the end of the year 2011. • www.windatlas.fi
Thank You! http://www.windatlas.fi http://en.ilmatieteenlaitos.fi