The Influence of Ocean Swell and Wind Waves on Iceberg Melting

Free-floating icebergs are important sources of cold freshwater to the polar oceans, influencing both ocean circulation and climate. The influence of ubiquitous oscillatory flows, like those resulting from local wind-driven waves and swells, on melting has not been extensively studied. To investigate such wave motion, here we conduct laboratory experiments in which fully submerged tall blocks of pure ice are oscillated vertically in a homogeneous saltwater environment and measure the resultant melting rates. Our results indicate that oscillatory motion strongly enhances melting rates, which are controlled by side melting, above a critical velocity threshold of 3–9 times the meltwater plume velocity, with the melting rate following a velocity to the 4/5ths scaling similar to previous results with steady motion. In addition, for sufficiently high frequency oscillations we observe regular small-scale scalloping. These results have important implications for improving the representation of iceberg sidewall melting in current ice-ocean models.