Landfast ice and coastal wave exposure in northern Alaska
AbstractObservations of ocean surface waves at three sites along the northern
coast of Alaska show a strong coupling with seasonal sea ice patterns.
In the winter, ice cover is complete, and waves are absent. In the
spring and early summer, sea ice retreats regionally, but landfast ice
persists near the coast. The landfast ice completely attenuates waves
formed farther offshore in the open water, causing up to two-month delay
in the onset of waves nearshore. In autumn, landfast ice begins to
reform, though the wave attenuation is only partial due to lower ice
thickness compared to spring. The annual cycle in the observations is
reproduced by the ERA5 reanalysis product, but the product does not
resolve landfast ice. The resulting ERA5 bias in coastal wave exposure
can be corrected by applying a higher resolution ice mask, and this has
a significant effect on the long-term trends inferred from ERA5.