Adhesion of laboratory grown Sea Spray Ice

Sea spray icing is a major safety concern for operations in polar regions. During a sea spray event several centimeters of sea spray ice can grow within an hour and can cause the inability to navigate and submerging of small vessels. The knowledge about the growth process and the properties of the ice growing in a sea spray event is limited. The adhesion strength of the ice is of particular concern, because it may limit the amount of sea spray ice that can grow before it is dropping due to its own weight. But data about the adhesion strength of spray ice is very limited. On the one hand it is difficult to measure; on the other hand, the focus during a natural spray event is the deicing to ensure operation of the structures. In the MICROSPRAY project at NTNU we perform for the first time systematic in-situ ice adhesion measurements on spray ice. The spray ice has been growing in a cold laboratory with air temperatures from -7 to -15\GradC and wind speeds from -10 to -15 m/s. Thus far, data about the adhesion strength of spray ice is very limited. On the one hand it is difficult to measure; on the other hand, the focus during a natural spray event is the deicing to ensure operation of the structures. In this work we present the setup used for the spray experiments and a first overview of the adhesion strength of sea spray ice based on in-situ testing.\\ KEY WORDS: Sea spray ice, marine icing, ice adhesion strength, brine channels, salinity