Drifting buoy observation of wave evolution in the Beaufort Sea marginal ice zone
Authors: Nose Takehiko , Waseda Takuji , Kodaira Tsubasa , Fujiwara Yasushi , Alberello Alberto , Nishizawa Keita 
Published: March 2021

&lt;p&gt;&lt;span&gt;Wave generation and growth via w&lt;/span&gt;&lt;span&gt;ind&amp;#160;&lt;/span&gt;&lt;span&gt;input&lt;/span&gt;&lt;span&gt;&amp;#160;in&amp;#160;&lt;/span&gt;&lt;span&gt;a&amp;#160;&lt;/span&gt;&lt;span&gt;marginal ice zone (MIZ)&amp;#160;&lt;/span&gt;&lt;span&gt;is&lt;/span&gt;&lt;span&gt;&amp;#160;&lt;/span&gt;&lt;span&gt;not a well&lt;/span&gt;&lt;span&gt;-understood process&amp;#160;&lt;/span&gt;&lt;span&gt;and&amp;#160;&lt;/span&gt;&lt;span&gt;remains&lt;/span&gt;&lt;span&gt;&amp;#160;&lt;/span&gt;&lt;span&gt;a neglected component&amp;#160;&lt;/span&gt;&lt;span&gt;in wave-ice models&lt;/span&gt;&lt;span&gt;.&amp;#160;&lt;/span&gt;&lt;span&gt;During the 2020 R/V Mirai&amp;#160;&lt;/span&gt;&lt;span&gt;observational&amp;#160;&lt;/span&gt;&lt;span&gt;campaign&amp;#160;&lt;/span&gt;&lt;span&gt;in the freezing season&lt;/span&gt;&lt;span&gt;,&amp;#160;&lt;/span&gt;&lt;span&gt;a&amp;#160;&lt;/span&gt;&lt;span&gt;3-day&amp;#160;&lt;/span&gt;&lt;span&gt;wave evolution event was captured in the Beaufort Sea MIZ by&amp;#160;&lt;/span&gt;&lt;span&gt;four&amp;#160;&lt;/span&gt;&lt;span&gt;drifting wave buoys&amp;#160;&lt;/span&gt;&lt;span&gt;that&amp;#160;&lt;/span&gt;&lt;span&gt;were&amp;#160;&lt;/span&gt;&lt;span&gt;spread zonally over&amp;#160;&lt;/span&gt;&lt;span&gt;a&amp;#160;&lt;/span&gt;&lt;span&gt;distance of roughly&amp;#160;&lt;/span&gt;&lt;span&gt;6&lt;/span&gt;&lt;span&gt;0 km. ERA5 s&lt;/span&gt;&lt;span&gt;urface wind speed &lt;/span&gt;&lt;span&gt;over&lt;/span&gt;&lt;span&gt;&amp;#160;the&lt;/span&gt;&lt;span&gt;se&lt;/span&gt;&lt;span&gt;&amp;#160;buoys&amp;#160;&lt;/span&gt;&lt;span&gt;were&amp;#160;&lt;/span&gt;&lt;span&gt;5&amp;#8211;10 ms&lt;sup&gt;-1&lt;/sup&gt;, and the direction was&amp;#160;&lt;/span&gt;&lt;span&gt;off-ice and&amp;#160;&lt;/span&gt;&lt;span&gt;primarily zonal, i.e., waves grew from&amp;#160;&lt;/span&gt;&lt;span&gt;ice cover to ice-free waters&lt;/span&gt;&lt;span&gt;.&amp;#160;&lt;/span&gt;&lt;span&gt;The peak&amp;#160;&lt;/span&gt;&lt;span&gt;significant&lt;/span&gt;&lt;span&gt;&amp;#160;wave heights were ~0.8 m and over 2 m&amp;#160;&lt;/span&gt;&lt;span&gt;for&lt;/span&gt;&lt;span&gt;&amp;#160;&lt;/span&gt;&lt;span&gt;the buoys&amp;#160;&lt;/span&gt;&lt;span&gt;located&amp;#160;&lt;/span&gt;&lt;span&gt;furthest&amp;#160;&lt;/span&gt;&lt;span&gt;from&lt;/span&gt;&lt;span&gt;&amp;#160;and nearest to the ice edge,&amp;#160;&lt;/span&gt;&lt;span&gt;respectively,&lt;/span&gt;&lt;span&gt;&amp;#160;&lt;/span&gt;&lt;span&gt;with&amp;#160;&lt;/span&gt;&lt;span&gt;sea ice concentrations&amp;#160;&lt;/span&gt;&lt;span&gt;between&amp;#160;&lt;/span&gt;&lt;span&gt;0.3 and 0.8&lt;/span&gt;&lt;span&gt;.&amp;#160;&lt;/span&gt;&lt;span&gt;The most notable features of the observation are as follows: 1) waves were seemingly generated in ice cover; 2) the wave age&lt;/span&gt;&lt;span&gt;&amp;#160;&lt;/span&gt;&lt;span&gt;was &lt;1&amp;#160;&lt;/span&gt;&lt;span&gt;(i.e., wind speed was slower than wave propagation)&lt;/span&gt;&lt;span&gt;&amp;#160;for the duration of the event at all the buoys.&amp;#160;&lt;/span&gt;&lt;span&gt;&amp;#160;We present analysis results with a physical viewpoint of&amp;#160;&lt;/span&gt;&lt;span&gt;wave evolution in freezing&amp;#160;&lt;/span&gt;&lt;span&gt;MIZ&lt;/span&gt;&lt;span&gt;s&lt;/span&gt;&lt;span&gt;.&lt;/span&gt;&lt;/p&gt;