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1. Supporting data for "Frozen flume experiments indicate rapid permafrost riverbank erosion depends on bank roughness"

   https://doi.org/10.15485/1972218  

   Douglas, Madison; Litwin_Miller, Kimberly; Schmeer, Maria; Lamb, Michael (January 2023, Environmental System Science Data Infrastructure for a Virtual Ecosystem; Incorporating the Hydrological Controls on Carbon Cycling in Floodplain Ecosystems into Earth System Models (ESMs))

   This dataset contains supporting files detailing five frozen flume experiments conducted at the Caltech Earth Surface Dynamics Laboratory to investigate rates of ablation-limited permafrost riverbank erosion under controlled conditions. Water flowed past a bank of saturated, frozen sand and ice and gradually eroded the bank by thawing pore ice and immediately entraining sand and washing it downstream. Experiments were scaled for flow hydraulics and heat transfer allowing comparisons between our results and natural permafrost riverbanks. For each experiment, we measured the initial and final sand bank topography using a Keyence laser scanner, water surface slope at 3-min intervals throughout the experiment using a Massa sonar scanner, bank erosion using 10-sec overhead timelapse imagery taken by an overhead camera, water and bank temperature using thermistors frozen into the sand bank and sampling at 2 Hz, and water discharge using an in-line flow meter. We include calibration data for the carriage (engineered by the Saint Anthony Falls Laboratory) used to make sonar and laser topography measurements. We also include calibration data for temperature sensors, water discharge measurements, and images of a regular grid placed in the flume to align overhead camera images with the carriage datum. Grain size analysis for the channel bed (gravel) was produced using a pebble count and bank sand was measured using a Camsizer X2. In addition to the five frozen experiments, we include sonar scans of water surface slope and Keyence scans of bed and bank topography for calibration experiments ran with an immobile gravel bank and bed. 

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2. Processed bathymetric data (netCDF grid) from 9°50'N, East Pacific Rise, acquired in 2018, 2019 and 2021 during AUV Sentry near-bottom dives

   https://doi.org/10.26022/IEDA/330373  

   Parnell-Turner, Ross; Fornari, Daniel; McDermott, Jill; Barreyre, Thibaut; Wu, Jyun-Nai (January 2022, Interdisciplinary Earth Data Alliance (IEDA))

   Bathymetric data were collected during a total of 19 AUV Sentry dives conducted from R/V Atlantis and R/V Roger Revelle during 2018 Atlantis cruise AT42-06 (two dives); 2019 Atlantis cruise AT42-21 (ten dives); and, 2021 Revelle cruise RR2102 (seven dives). Track lines were spaced 170 m apart, with Sentry about 65 m above bottom, collecting multibeam data using a 400 kHz Reson 7125 system in 2018, and a 400 kHz Kongsberg EM2040 system in 2019 and 2021. Sentry navigation was obtained using a 300 kHz Teledyne Doppler velocity log (DVL) and a Sonardyne AvTrak2 ultra-short baseline (USBL) acoustic positioning system, combined with an iXblue Phins inertial navigation system (INS), and a Paroscientific 8B7000-I Digiquartz depth sensor. Sonar data from all 19 dives were processed together using the open-source MB-System software, and were gridded at 1 m × 1 m node resolution using a beam footprint calculated with the angular beam widths and weighted by local slope. The grid file is in GMT-compatible netCDF format, in un-projected geographic coordinates. Funding was provided by National Science Foundation awards OCE-1834797, OCE1949485, OCE-1948936, and OCE-1949938. 

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3. Temporal evolution of under-ice meltwater layers and false bottoms and their impact on summer Arctic sea ice mass balance

   https://doi.org/10.1525/elementa.2022.00035  

   Salganik, Evgenii; Katlein, Christian; Lange, Benjamin A.; Matero, Ilkka; Lei, Ruibo; Fong, Allison A.; Fons, Steven W.; Divine, Dmitry; Oggier, Marc; Castellani, Giulia; et al (February 2023, Elementa: Science of the Anthropocene)

   Low-salinity meltwater from Arctic sea ice and its snow cover accumulates and creates under-ice meltwater layers below sea ice. These meltwater layers can result in the formation of new ice layers, or false bottoms, at the interface of this low-salinity meltwater and colder seawater. As part of the Multidisciplinary drifting Observatory for the Study of the Arctic Climate (MOSAiC), we used a combination of sea ice coring, temperature profiles from thermistor strings and underwater multibeam sonar surveys with a remotely operated vehicle (ROV) to study the areal coverage and temporal evolution of under-ice meltwater layers and false bottoms during the summer melt season from mid-June until late July. ROV surveys indicated that the areal coverage of false bottoms for a part of the MOSAiC Central Observatory (350 by 200 m2) was 21%. Presence of false bottoms reduced bottom ice melt by 7–8% due to the local decrease in the ocean heat flux, which can be described by a thermodynamic model. Under-ice meltwater layer thickness was larger below first-year ice and thinner below thicker second-year ice. We also found that thick ice and ridge keels confined the areas in which under-ice meltwater accumulated, preventing its mixing with underlying seawater. While a thermodynamic model could reproduce false bottom growth and melt, it could not describe the observed bottom melt rates of the ice above false bottoms. We also show that the evolution of under-ice meltwater-layer salinity below first-year ice is linked to brine flushing from the above sea ice and accumulating in the meltwater layer above the false bottom. The results of this study aid in estimating the contribution of under-ice meltwater layers and false bottoms to the mass balance and salt budget for Arctic summer sea ice. 

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4. ROV Teleoperation based on Sensory Augmentation and Digital Twins

   https://doi.org/10.4043/32376-MS  

   Xia, Pengxiang; McSweeney, Kevin P.; Song, Zhuoyuan; Du, Eric (April 2023, OTC)

   Abstract ROV operations are mainly performed via a traditional control kiosk and limited data feedback methods, such as the use of joysticks and camera view displays equipped on a surface vessel. This traditional setup requires significant personnel on board (POB) time and imposes high requirements for personnel training. This paper proposes a virtual reality (VR) based haptic-visual ROV teleoperation system that can substantially simplify ROV teleoperation and enhance the remote operator's situational awareness. This study leverages the recent development in Mixed Reality (MR) technologies, sensory augmentation, sensing technologies, and closed-loop control, to visualize and render complex underwater environmental data in an intuitive and immersive way. The raw sensor data will be processed with physics engine systems and rendered as a high-fidelity digital twin model in game engines. Certain features will be visualized and displayed via the VR headset, whereas others will be manifested as haptic and tactile cues via our haptic feedback systems. We applied a simulation approach to test the developed system. With our developed system, a high-fidelity subsea environment is reconstructed based on the sensor data collected from an ROV including the bathymetric, hydrodynamic, visual, and vehicle navigational measurements. Specifically, the vehicle is equipped with a navigation sensor system for real-time state estimation, an acoustic Doppler current profiler for far-field flow measurement, and a bio-inspired artificial literal-line hydrodynamic sensor system for near-field small-scale hydrodynamics. Optimized game engine rendering algorithms then visualize key environmental features as augmented user interface elements in a VR headset, such as color-coded vectors, to indicate the environmental impact on the performance and function of the ROV. In addition, augmenting environmental feedback such as hydrodynamic forces are translated into patterned haptic stimuli via a haptic suit for indicating drift-inducing flows in the near field. A pilot case study was performed to verify the feasibility and effectiveness of the system design in a series of simulated ROV operation tasks. ROVs are widely used in subsea exploration and intervention tasks, playing a critical role in offshore inspection, installation, and maintenance activities. The innovative ROV teleoperation feedback and control system will lower the barrier for ROV pilot jobs. 

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5. Towards Under-ice Sensing using a Portable ROV

   https://doi.org/10.1109/OCEANS47191.2022.9977140  

   Zhao, Lin; Zhou, Mingxi; Loose, Brice (October 2022, OCEANS 2022, Hampton Roads)

   Unmanned Underwater Vehicles (UUVs) have a promising future to explore the polar regions. In this paper, we present our progress on developing a self-contain inertial odometry for under-ice navigation. Firstly, a microcontroller-based hardware time synchronization for multiple devices is demonstrated. Moreover, we present a new IMU, Doppler Velocity Log (DVL) and Pressure dead-reckoning (DR) for state estimation and a robust initialization approach for underwater vehciels. Field trials have been conducted in Utqiagvik, Alaska in March 2022 to gather multi-sensor data under the sea ice. In this paper, we highlight the performance of our method by comparing to the robot_localization algorithm, a widely used open-source localization algorithm. 

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