Modeling VHF Scatter from FY and MY Sea Ice Ridges

Declining sea ice conditions are often cited as an indicator of climate change, but limited information is available on sea ice ridges, which comprise up to 50% of ice volume in certain regions. Multi-year (MY) ridges are more hazardous barriers to navigation than first year (FY) ridges and they are more likely to survive the summer melt season, but little effort has been made to identify FY and MY ridges from remote sensing data. This paper describes an analytical method to model electromagnetic scattering from ridges around the VHF range (100–500 MHz) when ridges are modeled as a rough surface over stratified media. Models considering the macroscopic properties of FY and MY ridges relevant to VHF scatter are presented. Simulations show that FY and MY ridges have different scattering characteristics, making it possible to separate the two ice types. Future work will consider how variability in ice ridge characteristics and changes during the ice season affect the separability of FY and MY ridges based on their scattering characteristics.