Exploring the Pacific Arctic Seasonal Ice Zone With Saildrone USVs

Abstract

More high-quality, in situ observations of essential marine variables are needed over the seasonal ice zone to better understand Arctic (or Antarctic) weather, climate, and ecosystems. To better assess the potential for arrays of uncrewed surface vehicles (USVs) to provide such observations, five wind-driven and solar-powered saildrones were sailed into the Chukchi and Beaufort Seas following the 2019 seasonal retreat of sea ice. They were equipped to observe the surface oceanic and atmospheric variables required to estimate air-sea fluxes of heat, momentum and carbon dioxide. Some of these variables were made available to weather forecast centers in real time. Our objective here is to analyze the effectiveness of existing remote ice navigation products and highlight the challenges and opportunities for improving remote ice navigation strategies with USVs. We examine the sources of navigational sea-ice distribution information based on post-mission tabulation of the sea-ice conditions encountered by the vehicles. The satellite-based ice-concentration analyses consulted during the mission exhibited large disagreements when the sea ice was retreating fastest (e.g., the 10% concentration contours differed between analyses by up to ∼175 km). Attempts to use saildrone observations to detect the ice edge revealed that in situ temperature and salinity measurements varied sufficiently in ice bands and open water that it is difficult to use these variables alone as a reliable ice-edge indicator. Devising robust strategies for remote ice zone navigation may depend on developing the capability to recognize sea ice and initiate navigational maneuvers with cameras and processing capability onboard the vehicles.

Validation of OSCAR Surface Currents in the Western Arctic Marginal Seas Against Saildrone Observations

“…In situ data used in this study are from two saildrones deployed in July–September of 2018 (1020, 1021) and three saildrones (1035, 1036, 1037) deployed in May ‐ September 2019 (Chiodi et al., 2021). They were launched from Dutch Harbor, Alaska crossed the Bering Strait into the Chukchi Sea (and Beaufort Sea in 2019) and headed south for recovery as the sunlight hours became short (Figures 1 and 2).…”

Validation of OSCAR Surface Currents in the Western Arctic Marginal Seas against Saildrone Observations

“…The saildrone's transiting speed is slowon average speed of 0.96 m/s, or ~18% of the average wind speed at 5.4 m/s during the 2019 deployment (Chiodi et al, 2021). This quiet vehicle is less affected by bubble issues (Joseph, 2014).…”

“…In situ data used in this study are from two saildrones deployed in July -September of 2018 (1020, 1021) and three saildrones (1035, 1036, 1037) deployed in May -September 2019 (Chiodi et al, 2021). They were launched from Dutch Harbor, Alaska crossed the Bering Strait into the Chukchi Sea (and Beaufort Sea in 2019) and headed south for recovery as the sunlight hours became short (Figure 1,2).…”

Toward Long-Term Sailing Robots: State of the Art From Energy Perspectives

“…A large number of applications have adopted Saildrones, such as marine mammals and fishes observation ( Mordy et al, 2017 ; Stierhoff et al, 2019 ; De Robertis et al, 2019 ; Kuhn et al, 2020 ), acidification observation ( Tilbrook et al, 2019 ), cold pools observation ( Wills et al, 2021 ), surface temperature and salinity gradients observation ( Vazquez-Cuervo et al, 2020 ; Vazquez-Cuervo et al, 2021 ), ocean CO 2 observation ( Sutton et al, 2021 ; Marouchos et al, 2018 ; Sabine et al, 2020 ), climate observation ( Meinig et al, 2019) ; Gentemann et al, 2020 ; Nagano and Ando, 2020 ), satellite ocean evaluation ( Scott et al, 2020 ; Meinig et al, 2015 ; Cokelet et al, 2015 ), gas or oil seep detection ( Scoulding et al, 2020 ; Daneshgar Asl et al, 2017 ), harsh environment exploration ( Chiodi et al, 2021 ), and ice zone observation ( Chiodi et al, 2021 ).…”