Examination of Sea Ice Cover in Norwegian Fjords

Presented are two steps being taken to examine sea ice coverage in Norwegian fjords as part of a larger study to improve our understanding of ice formation and breakup processes in these regions and implications for oil spill response. First, working with Google Earth Engine, MODIS images will be analyzed to determine where and when seasonal ice formation occurred along the Norwegian coastline since 2000. Here we summarize a simple method developed to quantify ice area in these regions to examine trends through the ice season and between years. While the larger study will cover a number of fjords, as an example focus is placed on Efjord, located in Nordland county, which has experienced large variations in ice coverage between years. We discuss the use of other datasets to determine the causes of such fluctuations focusing on the close relationship between run-off and ice cover in Efjord. Second, measurements of water temperature and salinity and ice thickness, stratigraphy, and salinity will be gathered over a three year period to better understand the ice observed in the MODIS images. The first set of measurements collected in November 2017 before freeze up are discussed below. In addition, initial images collected from time lapse cameras positioned to observe general weather and ocean conditions and the initial freeze up of ice are presented.submittedVersio

MOSIDEO/CIRFA Experiments on Behavior and Detection of Oil in Ice

- Preparedness and response to oil in sea ice-covered waters - When does oil melt out of the ice - When can oil be detected with remote sensing techniques?submittedVersio

Recent ice conditions in North-Norwegian Porsangerfjorden

Ice is a common occurrence in mainland Norwegian fjords in the vicinity of river mouths in winter. Fjord ice provides a wide array of services to society, including (1) acting as a coastal buffer (e.g. from pollution) and marine hazard; (2) providing a platform for recreational activities (e.g., travel and fishing); (3) serving as a full-scale model for Arctic sea ice (e.g., response training); and (4) participating in the fjord and coastal ecosystems. In spite of the local importance of ice in mainland Norwegian fjords, systematic investigations of its seasonal development and geophysical properties appear to be scarce. This study presents a summary of ice conditions in Porsangerfjorden from satellite observations of the past two decades (2000-2016) and discusses these in the context of local air temperature data and regional measurements of flow rates in rivers. Maximum ice extent was observed in March and a useful first approximation of ice extent in March could be derived from freezing degree days of February. However, local distribution of ice appears to be governed by factors beyond air temperature.publishedVersio

MOSIDEO/CIRFA Experiments on Behavior and Detection of Oil in Ice

- Preparedness and response to oil in sea ice-covered waters - When does oil melt out of the ice - When can oil be detected with remote sensing techniques

The Entrainment and Migration of Crude Oil in Sea Ice, the Use of Vegetable Oil as a Substitute, and Other Lessons from Laboratory Experiments

Understanding the interaction between oil and sea ice is essential in the development of oil spill detection and response technology in the Arctic. Laboratory experiments were performed to examine oil migration in sea ice during the cold phase and during warming, and investigate the behavior of different oils in sea ice to identify suitable substitute oils for crude oil. Vegetable oil and Troll B crude oil were injected underneath laboratory-grown sea ice with oil lenses either 1 cm or 3 cm in thickness. Results show similar behavior of vegetable oil and crude oil in sea ice both shortly after oil injection and during the warm phase. Further, results are independent of lens thickness. The implications of this result are discussed. In addition, the impact of cylindrical confinement of ice is shown on crystal and brine channel structure, and the energy balance of the tank are discussed.publishedVersio

Ice extent in sub-arctic fjords and coastal areas from 2001 to 2019 analyzed from MODIS imagery

Results 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 (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.publishedVersio

A low-cost coastal buoy for ice and metocean measurements

Regionally, an ice cover in fjords of mainland Norway may form and break up repeatedly during winter. Due to relatively high water temperatures, the freeze-up process is expected to be related to freshwater-induced stratification in the fjords in conjunction with low air temperatues. In an attempt to identify the variability of water conditions in the fjords leading up to and during ice cover development, a low-cost buoy had been developed to cope with the high potential of loss of equipment during break-up of ice. The current version of the buoy logs GPS coordinates and ocean, ice and air temperature, and transmits data through the cell phone network. Experience from the first season of multiple deployments showed that the concept is working but the physical design of the buoy could be improved to withstand forces in open water.A low-cost coastal buoy for ice and metocean measurementspublishedVersio

Recent ice conditions in North-Norwegian Porsangerfjorden

Ice is a common occurrence in mainland Norwegian fjords in the vicinity of river mouths in winter. Fjord ice provides a wide array of services to society, including (1) acting as a coastal buffer (e.g. from pollution) and marine hazard; (2) providing a platform for recreational activities (e.g., travel and fishing); (3) serving as a full-scale model for Arctic sea ice (e.g., response training); and (4) participating in the fjord and coastal ecosystems. In spite of the local importance of ice in mainland Norwegian fjords, systematic investigations of its seasonal development and geophysical properties appear to be scarce. This study presents a summary of ice conditions in Porsangerfjorden from satellite observations of the past two decades (2000-2016) and discusses these in the context of local air temperature data and regional measurements of flow rates in rivers. Maximum ice extent was observed in March and a useful first approximation of ice extent in March could be derived from freezing degree days of February. However, local distribution of ice appears to be governed by factors beyond air temperature

Effect of Oil Pollution and Ice Formation on Microbial Community of Seawater from Ofotfjorden, Norway

Oil spill in ice-covered waters can become entrapped in sea ice and may be subjected to biodegradation by sea ice microorganisms. The extent of the hydrocarbon biodegradation, and microorganisms involved in such process in sea ice are not well understood. In this study, we performed ice formation in lab-tanks (125 l) with unpolluted seawater from Ofotfjorden, Norway. The tanks were insulated at the perimeter and bottom with Styrofoam and heated from the bottom so that ice only grew from the tank surface. Troll B crude oil was injected underneath the ice, forming an oil lens which later was encapsulated in the ice as the ice con-tinued growing. The ice was harvested and stored at -14°C for 3 months following encapsula-tion. Metagenomic analysis of the microbial communities in the ice samples which formed in the lab showed changes in the microbial community structure with dominance of Alpha- and Gammaproteobacteria. At the same time, Archaea, Bacteroidetes and Actinobacteria reduced significantly in the ice compare to the original seawater. No significant change of the microbi-al community in the ice was observed in the presence of the oil. However, a slight increase in abundance of some bacterial genera such as Cowellia, Glaciecola and Acrobacter was detect-ed among the phylotypes of the oil-contaminated ices. Member of genera Cowellia and Glaciecola are common sea-ice inhabitants and have been known for their n-alkanes and aro-matic hydrocarbons metabolism capacity. Despite this development, no significant loss of the oil or change of n-C17/Pristane or n-C18/Phytane ratio was detected. But a slight reduction of water soluble PAHs was observed that may results from microbial activity in the ice.Effect of Oil Pollution and Ice Formation on Microbial Community of Seawater from Ofotfjorden, NorwayacceptedVersio

The Entrainment and Migration of Crude Oil in Sea Ice, the Use of Vegetable Oil as a Substitute, and Other Lessons from Laboratory Experiments

Understanding the interaction between oil and sea ice is essential in the development of oil spill detection and response technology in the Arctic. Laboratory experiments were performed to examine oil migration in sea ice during the cold phase and during warming, and investigate the behavior of different oils in sea ice to identify suitable substitute oils for crude oil. Vegetable oil and Troll B crude oil were injected underneath laboratory-grown sea ice with oil lenses either 1 cm or 3 cm in thickness. Results show similar behavior of vegetable oil and crude oil in sea ice both shortly after oil injection and during the warm phase. Further, results are independent of lens thickness. The implications of this result are discussed. In addition, the impact of cylindrical confinement of ice is shown on crystal and brine channel structure, and the energy balance of the tank are discussed