The Arctic Fjord Breeze: Characteristics of a Combined Sea Breeze and Valley Wind in a Svalbard Fjord Valley

Thermally-driven circulations are a frequent meteorological phenomenon in complex Arctic terrain, but the Arctic fjord breeze, a combined sea-breeze and up-valley wind, has received little attention. A field campaign was conducted in the valley Adventdalen in Svalbard in summer 2022 using a Scanning Doppler Lidar and automatic weather stations. It is shown that a local up-valley circulation occurred frequently in this valley, and that it was driven by the temperature and pressure gradient between valley and fjord, i.e., a fjord breeze. The fjord breeze existed in both large-scale up-valley and down-valley winds. Its strength, extent and depth varied due to the diurnal cycle of solar irradiation as well as the interaction with large-scale winds. In contrast to typical lower-latitude breezes, the Arctic fjord breeze could persist over several days. The breeze was found to be relatively strong even under small horizontal temperature contrasts and opposing large-scale winds, possibly due to an increase in the thermal pressure gradient by the surrounding topography.