Wind, waves, and surface currents in the Southern Ocean: observations from the Antarctic Circumnavigation Expedition

Abstract

Abstract. The Southern Ocean has a profound impact on the Earth's climate system. Its strong winds, intense currents, and fierce waves are critical components of the air–sea interface and contribute to absorbing, storing, and releasing heat, moisture, gases, and momentum. Owing to its remoteness and harsh environment, this region is significantly undersampled, hampering the validation of prediction models and large-scale observations from satellite sensors. Here, an unprecedented data set of simultaneous observations of winds, surface currents, and ocean waves is presented, to address the scarcity of in situ observations in the region – https://doi.org/10.26179/5ed0a30aaf764 (Alberello et al., 2020c) and https://doi.org/10.26179/5e9d038c396f2 (Derkani et al., 2020). Records were acquired underway during the Antarctic Circumnavigation Expedition (ACE), which went around the Southern Ocean from December 2016 to March 2017 (Austral summer). Observations were obtained with the wave and surface current monitoring system WaMoS-II, which scanned the ocean surface around the vessel using marine radars. Measurements were assessed for quality control and compared against available satellite observations. The data set is the most extensive and comprehensive collection of observations of surface processes for the Southern Ocean and is intended to underpin improvements of wave prediction models around Antarctica and research of air–sea interaction processes, including gas exchange and dynamics of sea spray aerosol particles. The data set has further potentials to support theoretical and numerical research on lower atmosphere, air–sea interface, and upper-ocean processes.

Three-dimensional imaging of waves and floe sizes in the marginal ice zone during an explosive cyclone

“…defined, and the maximum is ≈ 75 • at d = 36 km. The directional spread agrees with typical open water values during storms in the Southern Ocean [34].…”

Interactions between Irregular Wave Fields and Sea Ice: A Physical Model for Wave Attenuation and Ice Breakup in an Ice Tank

“…The small steepness incident wave field in the first test (ε = 0.02; Fig. 3a) is a lower bound for expected sea states in the Arctic Ocean [de Souza Cabral, 2020] and rarely experienced in the Southern Ocean [Derkani et al, 2021]. It propagates through the continuous ice cover without generating any visible fractures.…”

“…The intermediate steepness incident field (ε = 0.04) is common in the Arctic Ocean [de Souza Cabral, 2020] and a lower bound in the Southern Ocean [Derkani et al, 2021]. The ice edge breaks up as soon as the incident field reaches it, with breakup both longitudinal (parallel to the wave crests) and transverse (along the direction of wave propagation).…”

“…The steepest incident field (ε = 0.06) is an upper bound for the Arctic Ocean [de Souza Cabral, 2020] and an average condition in the Southern Ocean [Derkani et al, 2021]. Starting from a partially broken ice cover, the steep incident field breaks up the remaining continuous ice cover.…”

Exploring the coupled ocean and atmosphere system with a data science approach applied to observations from the Antarctic Circumnavigation Expedition

“…Between 40 and 60 • S, the strong westerly wind belt develops nearly unhindered by land masses (Fig. 1, (v)), making the Southern Ocean the stormiest and fiercest ocean in the world (Hanley et al, 2010;Derkani et al, 2021). Winds and waves strongly modulate ocean mixing (Thorpe, 2007;Toffoli et al, 2012), biological production (Nicholson et al, 2016;Uchida et al, 2020), air-sea gas exchange (Wanninkhof et al, 2009;Gruber et al, 2019), sea ice dynamics (Alberello et al, 2020;Vichi et al, 2019;Holland and Kwok, 2012), and sea spray emission (Fig.…”