Case studies of the wind field around Ny-Ålesund, Svalbard, using unmanned aircraft

• Main Authors: Schön, Martin, Suomi, Irene, Altstädter, Barbara, van Kesteren, Bram, zum Berge, Kjell, Platis, Andreas, Wehner, Birgit, Lampert, Astrid, Bange, Jens
• Format: Article in Journal/Newspaper
• Language: English
• Published: London : Taylor & Francis 2022
• Subjects: ddc:550; ddc:570; aircraft measurement; Arctic fjord; boundary layer; Kongsfjorden; Microscale meteorology; wind measurement; Kongsfjord*; Ny Ålesund; Ny-Ålesund; Svalbard
• Online Access: https://oa.tib.eu/renate/handle/123456789/11610; https://doi.org/10.34657/10643

The wind field in Arctic fjords is strongly influenced by glaciers, local orography and the interaction between sea and land. Ny-Ålesund, an important location for atmospheric research in the Arctic, is located in Kongsfjorden, a fjord with a complex local wind field that influences measurements in Ny-Ålesund. Using wind measurements from UAS (unmanned aircraft systems), ground measurements, radiosonde and reanalysis data, characteristic processes that determine the wind field around Ny-Ålesund are identified and analysed. UAS measurements and ground measurements show, as did previous studies, a south-east flow along Kongsfjorden, dominating the wind conditions in Ny-Ålesund. The wind measured by the UAS in a valley 1 km west of Ny-Ålesund differs from the wind measured at the ground in Ny-Ålesund. In this valley, we identify a small-scale catabatic flow from the south to south-west as the cause for this difference. Case studies show a backing (counterclockwise rotation with increasing altitude) of the wind direction close to the ground. A katabatic flow is measured near the ground, with a horizontal wind speed up to 5 m s-1. Both the larger-scale south-east flow along the fjord and the local katabatic flows lead to a highly variable wind field, so ground measurements and weather models alone give an incomplete picture. The comparison of UAS measurements, ground measurements and weather conditions analysis using a synoptic model is used to show that the effects measured in the case studies play a role in the Ny-Ålesund wind field in spring.