Temporal changes in wind conditions at Svalbard for the years 1986–2015

ABSTRACT

This paper presents trends in wind speed and wind direction indices at selected stations in Svalbard (Bjørnøya, Hopen and Ny-Ålesund) and in the NCEP/NCAR and ERA-Interim reanalysis for the period 1986–2015. The analysed wind indices include the sum of days (annual or seasonal) with the daily range wind speed or wind direction. Using the Mann-Kendall trend test, we look for temporal trends in these indices, compare the results for the measured and gridded datasets, and then analyse the spatial variability in those trends. For the stations, statistically significant decreasing trends are detected for the frequency of days with very low wind speed (≤2 m s⁻¹) and for days with strong wind (>10 m s⁻¹). From the reanalysis data, indices with wind speed of up to 5 m s⁻¹ were characterized by decreasing trends, while indices with wind speed above the mentioned threshold show increasing trends. Wind direction indices are characterized by different tendencies in the Ny-Ålesund station, where local elements modify the dominant directions of the air mass advection. The trends vary in space for the given region. Reanalysis data show the biggest positive trend for the occurrence of northerly winds over the Greenland Sea and Arctic Ocean, which cannot be confirmed by measurements (no stations available). The trends in wind speed and direction indices may partly be explained by changes in the frequency of circulation patterns.

KEYWORDS:

• Wind variability
• wind indices
• trends
• climate change
• reanalysis
• Svalbard

Acknowledgements

We hereby acknowledge the data providers in the ECA&D Project. The authors would like to thank Nina Elisabeth Larsgård (Norwegian Meteorological Institute) for the information on wind measurements and instruments used at the meteorological stations on Svalbard.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Natalia Pilguj is a Ph.D. student at the Department of Climatology and Atmosphere Protection, University of Wrocław. Her research concentrates on numerical modelling of weather conditions and climatology of polar regions.

Leszek Kolendowicz is a full professor of climatology and head of the Department of Climatology, Adam Mickiewcz University in Poznań, working on influence of atmospheric circulation on meteorological phenomena and climatology of polar regions.

Maciej Kryza is a Ph.D. (with habilitation) working in the Department of Climatology and Atmosphere Protection, University of Wrocław. His research interests include meteorological modelling and air pollution.

Krzysztof Migała is a full professor and head of the Department of Climatology and Atmosphere Protection at University of Wrocław. His research concentrates on polar regions’ climatology.

Bartosz Czernecki is a Ph.D. and Assistant Professor at the Department of Climatology, Adam Mickiewcz University in Poznań, working on modelling of atmospheric processes.

Additional information

Funding

This work was supported by the National Science Centre (NCN); Narodowe Centrum Nauki Poland, under grant number UMO-2014/15/B/ST10/04455. Calculations of reanalysis data were carried out in the Wroclaw Centre for Networking and Supercomputing (http://www.wcss.wroc.pl), grant no 170.