Author(s): Megan O’Sadnick; Chris Petrich
Linked Author(s):
Keywords: Fjord oceanography; Brackish ice; Norway; Ice extent; Seawater properties
Abstract:
From 1976 – 93, measurements of seawater temperature and salinity throughout the year and ice extent during winter were gathered in Nordfjord and Holandsfjord, Norway by Norges Vassdrags- og Energidirektorat. These measurements are unique as they offer a long-term record of both CTD profiles and ground observations of ice conditions in a Norwegian fjord. The formation of ice in mainland Norwegian fjords is often connected to the presence of a brackish surface layer with the impact of seawater temperature and salinity below this top layer not well investigated. Here, observations of ice extent in Nordfjorden and Holandsfjorden are first compared to an adapted calculation of degree days revealing trends in ice formation and length of the ice season aligned with daily air temperatures. Measurements of seawater salinity and temperature throughout the fjord are next compared to the number of days with ice at the head of the fjord. Ice coverage is found to be most consistently and significantly related to seawater properties close to a river output however there are indications of ice coverage being connected to oceanic processes further down fjord as well.
Year: 2024