Abstract
AbstractResults examining variations in the ice extent along the Norwegian coastline based on the analysis of Moderate Resolution Imaging Spectroradiometer (MODIS) images from 2001 to 2019, February through May, are presented. A total of 386 fjords and coastal areas were outlined and grouped into ten regions to assess seasonal and long-term trends in ice extent. In addition, three fjords were examined to investigate how ice extent may vary over short distances (<100 km). Of the 386 outlined, 47 fjords/coastal areas held >5 km2 of ice at least once between 2001 and 2019. Over this span of time, no statistically significant trend in ice extent is found for all ten regions; however, variations between regions and years are evident. Ice extent is assessed through comparison to three weather variables – freezing degree days (FDD), daily new snowfall and daily freshwater supply from rainfall plus snowmelt. Six out of ten regions are significantly positively correlated (p < 0.05) to FDD. In addition, ice in two regions is significantly positively correlated to daily new snowfall, and in one region negatively correlated to rainfall plus snowmelt. The importance of fjord geometry and bathymetry as well as other weather variables including wind is discussed.
Highlights
The coast of mainland Norway is dominated by the presence of fjords
We examine correlations between ice extent and several variables related to weather: air temperature, new snowfall and rainfall plus snowmelt
While the majority of the analysis presented here focuses on the ten selected regions, results from individual fjords and areas along the coast were examined to understand if and how many contributed most to higher values of ice extent
Summary
The coast of mainland Norway is dominated by the presence of fjords. Often subjected to air temperatures below freezing, sea ice has the possibility to form in these regions. It is understood that one condition important, often necessary, for ice to form in fjords is a layer of brackish water on the surface (Gade, 1986). This water can be less dense than the warmer ocean water below, leading to little vertical mixing and a stable water column that promotes cooling and ice formation at the surface (Manak and Mysak, 1989; Ogi and Tachibana, 2001). Calm oceanic and atmospheric conditions must be present to allow for the stratified water column to form These requirements of fresh water and calm conditions make ice formation a local effect, likely to vary between fjords and years
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
