The ECMWF Reanalysis v5 (ERA5), the New European Wind Atlas (NEWA), and the 3 km Norwegian Reanalysis (NORA3) are reference datasets that are available for industry and research. The resolution of 3km in both the NORA3 and NEWA datasets sets them apart, while ERA5, with its 31km resolution, continues to serve as a reliable data source that is widely used in the industry. The study offers a thorough analysis of three datasets from three research stations in Sweden, which are accessible through the Integrated Carbon Observation System (ICOS). It has been discovered that all three reference datasets exhibit a strong alignment with the measured data. However, NORA3 and ERA5 outperform NEWA in wind speed and direction estimation. The computation of Annual Energy Production (AEP) using WindPro is performed. We examine the representativeness of the correlation coefficient between the Weibull scale and shape parameters, the agreement of wind rose distributions, and the estimated AEP.

En stor del av Sveriges energiproduktion kommer från vattenkraftverken. Dessa kraftverk använder sig av vattenmagasin för att hålla kvar vattenmassa och dammar för att reglera det vattenflöde som ger upphov till energiproduktionen. Efter vinterperioderna uppstår vårfloder, tillfälligt stora mängder vatten från snösmältningen, som kraftigt påverkar vattenmängden i kraftverkens vattenmagasin. Därför behöver regleringar av vattenmängden göras för att kunna ta emot den nya mängd vatten som tros tillkomma under vårfloden. Att göra korrekta prognoser för den rätta regleringen är idag svårt då de tillhörande avrinningsområdena är  tusentals kvadratkilometer stora och endast ett fåtal mätstationer finns tillgängliga. Syftet med detta projekt är att utveckla en metod för att bestämma fördelningen av snömängden i ojämn terräng, med vindriktningen som den största faktorn, för att kunna förutse avrinningens förändring under smältsäsongen.  De huvudsakliga arbetsverktyg som har använts är ArcGIS, Matlab, Excel och geostatiska metoder i kombination. Projektet är kopplat till ett nytt forskningsprojekt (SNODDAS, 2018) finansierat av Energimyndigheten som syftar till att ta fram bättre prognosmodeller för snökapaciteteten i avrinningsområden till vattenkraftsdammar. Det är ett samarbete mellan Uppsala universitet, SMHI och Vattenregleringsföretagen. Var snön kommer att hamna beror på terrängen och den dominerande vindriktningen. Därför kommer denna modell att definiera den del av terrängen som ligger upp-vind mot den dominerande vindriktningen som Sx. Modellens syfte är att beräkna snödistributionen och dess ackumulering i ett områdes höjddata med hjälp av 8 framtagna filer med olika Sx-värden för olika vindriktningar, också kallat Sheltering Index, med vindriktningar från 0º-360º med steg om 45º och sammanställda mätdata för vinterperioden 2017/2018 (19 oktober till 14 april). Det slutliga resultatet blev 61%, 63% och 90% jämfört med beräknad snövattenekvivalent av SeNorge (Norwegian Water Resources and Energy Directorate, 2019). / A large part of Sweden's energy production comes from hydroelectric power plants. These power plants use water reservoirs to retain water mass and dams to regulate the water flow that generates energy production. After the winter periods the large spring rivers, water from the snow melt, greatly affect the amount of water in the power plants' water reservoirs which makes it necessary to make regulations in order to be able to receive the amount of water that is believed to be added during the spring flows. Making accurate forecasts for the right regulations is difficult today as the associated river basins are several thousand square kilometers large and only a few measuring stations are available. This project aims to develop a method for determining the distribution of snow in uneven terrain, with the wind direction being the largest factor, in order to be able to foresee the change of runoff during the melting season. Main work tools are ArcGIS, Matlab, Excel and geostatic methods in combination. The project is linked to a new research project (SNODDAS, 2018) funded by the Swedish Energy Agency, which aims to develop better forecast models for the snow capacity in river basins to hydroelectric power dams. It is a collaboration between Uppsala University, SMHI and water regulation companies. Where the snow will end up depends on the terrain and the dominant wind direction. Therefore, this model will define the part of the terrain that lies up against the dominant wind direction as Sx. The purpose of the model is to calculate the snow distribution and its accumulation in the height data of an area with the aid of 8 files produced with different Sx values for different wind directions, also called the Sheltering Index, with wind directions from 0º-360º with steps of 45º and aggregated measurement data for the winter period 2017/2018 (19 October to 14 April). The results after calculations were 61%, 63% and 90% compared to the snow water equivalent from SeNorge (Norwegian Water Resources and Energy Directorate, 2019).

This thesis presents the distribution of strong wind and wind pressure in the Greater Victoria area associated with winter mid-latitude cyclones based on climate data from the School-Based Weather Station Network during 6 selected days in the winters of 2006, 2007 and 2008. The objectives of this study are i) to test whether synoptic conditions favourable to severe mid-latitude cyclonic storms that are well described in the literature were associated with the selected storms, ii) to determine the time patterns of high wind speed and its direction and maximum gusts, iii) to test necessity of considering the spatial variation in air density and its controls in general assessments of the spatial variation in wind pressure and wind damage potential in the local area, iv) to identify potential areas susceptible to wind damage. Observations taken every second were from Davis Vantage Pro2 TM Plus weather stations located on the southern edge of school building roofs. Thirty-minute means and gust wind speeds were used. All six storms went north of Victoria. The synoptic conditions associated with the selected mid-latitude cyclones agreed with the ones described in literature. Strongest winds at most stations were generally from the southwest, and multiple wind speed peaks were found. The daily iii  maximum gust wind speeds were found before and/or after the highest mean wind speed peak. The spatial variation in air density and its controls were found to be negligible. Although there are a number of interacting causes of the distribution, strongest winds were at stations with smooth surrounding surfaces, close to the southern shoreline, on exposed slopes and/or near relief constrictions. The area with greatest wind speeds and damage potential was found from the east of downtown extending to Lansdowne Middle School. This study provides new knowledge of winds in the Greater Victoria area and contributes to people’s better response to wind storms, land use planning and forecasting severe windstorms. / Graduate / 0368 / mmatsuda@uvic.ca

This thesis presents the distribution of strong wind and wind pressure in the Greater Victoria area associated with winter mid-latitude cyclones based on climate data from the School-Based Weather Station Network during 6 selected days in the winters of 2006, 2007 and 2008. The objectives of this study are i) to test whether synoptic conditions favourable to severe mid-latitude cyclonic storms that are well described in the literature were associated with the selected storms, ii) to determine the time patterns of high wind speed and its direction and maximum gusts, iii) to test necessity of considering the spatial variation in air density and its controls in general assessments of the spatial variation in wind pressure and wind damage potential in the local area, iv) to identify potential areas susceptible to wind damage. Observations taken every second were from Davis Vantage Pro2 TM Plus weather stations located on the southern edge of school building roofs. Thirty-minute means and gust wind speeds were used. All six storms went north of Victoria. The synoptic conditions associated with the selected mid-latitude cyclones agreed with the ones described in literature. Strongest winds at most stations were generally from the southwest, and multiple wind speed peaks were found. The daily iii  maximum gust wind speeds were found before and/or after the highest mean wind speed peak. The spatial variation in air density and its controls were found to be negligible. Although there are a number of interacting causes of the distribution, strongest winds were at stations with smooth surrounding surfaces, close to the southern shoreline, on exposed slopes and/or near relief constrictions. The area with greatest wind speeds and damage potential was found from the east of downtown extending to Lansdowne Middle School. This study provides new knowledge of winds in the Greater Victoria area and contributes to people’s better response to wind storms, land use planning and forecasting severe windstorms. / Graduate / 0368 / mmatsuda@uvic.ca