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arXiv 2022年

作者： Horowitz, Jess Preston, Victoria Michel, Anna P.M. Mechanical Engineering Massachusetts Institute of Technology Cambridge United States MIT-WHOI Joint Program Massachussetts Institute of Technology Cambridge United States Applied Ocean Physics and Engineering Woods Hole Oceanographic Institution Woods Hole United States

Estimates of greenhouse gas emissions from Arctic estuarine environments are dominated by in situ summer-time ice-free dissolved gas measurements due to the logistical ease of performing field observations in these conditions. Recent evidence in coastal Arctic environments, however, has demonstrated that dissolved methane (CH4) and carbon dioxide (CO2) are strongly seasonally variable, and at least one significant gas ventilation event occurs during the spring freshet. Whether the Arctic serves as a source or sink of greenhouse emissions has significant implications on modeling climate change and its feedback mechanisms. To enable higher resolution spatiotemporal measurements of dissolved gases in typically undersampled conditions, remotely operated vehicles (ROVs) can be used to extract near continuous water samples below ice before and during the spring freshet. Here, we present a size, weight, and power-constrained (SWAP) underwater vehicle (UV) and novel geochemical sampling system suitable for taking under-ice geochemical observations and demonstrate the proposed system in a field-analog setting for Arctic estuarine studies. Copyright © 2022, The Authors. All rights reserved.

关键词： Carbon dioxide

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Robotic Planning under Uncertainty in Spatiotemporal Environments in Expeditionary Science

arXiv

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arXiv 2022年

作者： Preston, Victoria Flaspohler, Genevieve Michel, Anna P.M. Fisher, John W. Roy, Nicholas MIT-WHOI Joint Program Massachusetts Institute of Technology CambridgeMA02139 United States Applied Ocean Physics and Engineering Woods Hole Oceanographic Institution United States Computer Science and Artificial Intelligence Laboratory Massachusetts Institute of Technology CambridgeMA02139 United States

In the expeditionary sciences, spatiotemporally varying environments - hydrothermal plumes, algal blooms, lava flows, or animal migrations - are ubiquitous. Mobile robots are uniquely well-suited to study these dynamic, mesoscale natural environments. We formalize expeditionary science as a sequential decision-making problem, modeled using the language of partially-observable Markov decision processes (POMDPs). Solving the expeditionary science POMDP under real-world constraints requires efficient probabilistic modeling and decision-making in problems with complex dynamics and observational models. Previous work in informative path planning, adaptive sampling, and experimental design have shown compelling results, largely in static environments, using data-driven models and information-based rewards. However, these methodologies do not trivially extend to expeditionary science in spatiotemporal environments: they generally do not make use of scientific knowledge such as equations of state dynamics, they focus on information gathering as opposed to scientific task execution, and they make use of decision-making approaches that scale poorly to large, continuous problems with long planning horizons and real-time operational constraints. In this work, we discuss these and other challenges related to probabilistic modeling and decision-making in expeditionary science, and present some of our preliminary work that addresses these gaps. We ground our results in a real expeditionary science deployment of an autonomous underwater vehicle (AUV) in the deep ocean for hydrothermal vent discovery and characterization. Our concluding thoughts highlight remaining work to be done, and the challenges that merit consideration by the reinforcement learning and decision-making community. Copyright © 2022, The Authors. All rights reserved.

关键词： Decision making

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Tracking Sargassum in the Caribbean: The Deployment and Validation of a Low-Cost Surface Drifter

SSRN

引用

SSRN 2023年

作者： Pixa, Chase Manganini, Kevin Myers, Alyson Michel, Anna P.M. Department of Applied Ocean Physics and Engineering Woods Hole Oceanographic Institution 266 Woods Hole Road Woods HoleMA02543 United States Department of Mechanical Engineering Massachusetts Institute of Technology 77 Massachusetts Ave CambridgeMA02139 United States MIT-WHOI Joint Program in Oceanography/Applied Ocean Science & Engineering Cambridge and Woods Hole MA United States Fearless Fund 3029 Woodland Drive NW WashingtonDC20008 United States

Sargassum blooms have been causing significant ecological and economic damage to coastal regions in the Northern Equatorial Atlantic since 2011. To better understand the movement and effects of this macroalgae, there is a need to track its transport. In this study, a low-cost drifter was deployed, designed to entangle with Sargassum and aid in its tracking. The design was based on the results of twenty-seven drifter designs and five days of field trials. The tracking data was validated using gridded wind and current products, as well as high resolution satellite imagery. The successful entanglement and tracking with the Sargassum demonstrated in this study can provide in situ movement data to ground-truth models and supplement gaps in satellite imaging. The results can guide future studies and further our understanding of its movement in the great Atlantic Sargassum belt (GASB). © 2023, The Authors. All rights reserved.

关键词： Costs

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Corrigendum to “Lipid composition, caloric content, and novel oxidation products from microbial communities within seasonal pack ice cores” [Geochimica et Cosmochimica Acta 368 (2024) 12–23]

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Geochimica et Cosmochimica Acta 2024年 382卷 161-161页

作者： Henry C. Holm Helen F. Fredricks Shavonna M. Bent Daniel P. Lowenstein Kharis R. Schrage Benjamin A.S. Van Mooy Marine Chemistry and Geochemistry Department Woods Hole Oceanographic Institution Woods Hole MA 02543 USA MIT-WHOI Joint Program in Oceanography/Applied Ocean Science & Engineering Cambridge MA 02139 USA

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Tunable Diode Laser Absorption Spectroscopy Instrument for Flow-Through Measurement of Dissolved Carbon Dioxide in the Ocean

Tunable Diode Laser Absorption Spectroscopy Instrument for F...

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Conference on Lasers and Electro-Optics (CLEO)

作者： Beckett Colson Anna P. M. Michel Woods Hole Oceanographic Institution Woods Hole MA USA Massachusetts Institute of Technology Cambridge MA USA MIT-WHOI Joint Program in Oceanography/Applied Ocean Science & Engineering Cambridge and Woods Hole MA USA

The measurement of dissolved carbon dioxide is important for understanding many ocean processes. Here we present the design and field deployment of a TDLAS sensor for the measurement of dissolved carbon dioxide.

ISBN: (纸本)9781943580910

关键词： Spectroscopy Semiconductor lasers Oceans Instruments Sea measurements Measurement by laser beam Carbon dioxide

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Active Reward Learning for Co-Robotic Vision Based Exploration in Bandwidth Limited Environments

Active Reward Learning for Co-Robotic Vision Based Explorati...

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IEEE International Conference on Robotics and Automation (ICRA)

作者： Stewart Jamieson Jonathan P. How Yogesh Girdhar MIT-WHOI Joint Program in Applied Ocean Science and Engineering Department of Aeronautics and Astronautics at the Massachusetts Institute of Technology (MIT) Applied Ocean Physics and Engineering Department The Woods Hole Oceanographic Institution (WHOI)

ISBN: (数字)9781728173955

ISBN: (纸本)9781728173962

We present a novel POMDP problem formulation for a robot that must autonomously decide where to go to collect new and scientifically relevant images given a limited ability to communicate with its human operator. From this formulation we derive constraints and design principles for the observation model, reward model, and communication strategy of such a robot, exploring techniques to deal with the very high-dimensional observation space and scarcity of relevant training data. We introduce a novel active reward learning strategy based on making queries to help the robot minimize path "regret" online, and evaluate it for suitability in autonomous visual exploration through simulations. We demonstrate that, in some bandwidth-limited environments, this novel regret-based criterion enables the robotic explorer to collect up to 17% more reward per mission than the next-best criterion.

关键词： Robot sensing systems Semantics Bandwidth Computational modeling Visualization Trajectory

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Corrigendum to “Biochemical implications of the Bottom Boundary Layer Detachment at the Mid-Atlantic Bight shelf-break front” [Continent. Shelf Res. 286 (2025) 105408]

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Continental Shelf Research 2025年 288卷

作者： Serena Negroni Dennis J. McGillicuddy Glen G. Gawarkiewicz Paolo Oddo Nadia Pinardi Department of Physics and Astronomy (DIFA) University of Bologna Bologna 40126 Italy MIT/WHOI Joint Program in Oceanography/Applied Ocean Sciences and Engineering Woods Hole 02543 MA USA Woods Hole Oceanographic Institution Woods Hole 02543 MA USA

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Lagrangian surface signatures reveal upper-ocean vertical displacement conduits near oceanic density fronts

arXiv

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arXiv 2022年

作者： Aravind, H.M. Verma, Vicky Sarkar, Sutanu Freilich, Mara A. Mahadevan, Amala Haley, Patrick J. Lermusiaux, Pierre F.J. Allshouse, Michael R. Mechanical and Industrial Engineering Northeastern University BostonMA02115 United States Mechanical and Aerospace Engineering University of California San Diego La Jolla CA92093 United States MIT–WHOI Joint Program in Oceanography CambridgeMA02139 United States Woods Hole Oceanographic Institution Woods HoleMA02543 United States Department of Mechanical Engineering Massachusetts Institute of Technology CambridgeMA02139 United States

Vertical transport in the ocean plays a critical role in the exchange of freshwater, heat, nutrients, and other biogeochemical tracers. While there are situations where vertical fluxes are important, studying the vertical transport and displacement of material requires analysis over a finite interval of time. One such example is the subduction of fluid from the mixed layer into the pycnocline, which is known to occur near density fronts. Divergence has been used to estimate vertical velocities indicating that surface measurements, where observational data is most widely available, can be used to locate these vertical transport conduits. We evaluate the correlation between surface signatures derived from Eulerian (horizontal divergence, density gradient, and vertical velocity) and Lagrangian (dilation rate and finite time Lyapunov exponent) metrics and vertical displacement conduits. Two submesoscale resolving models of density fronts and a data-assimilative model of the western Mediterranean were analyzed. The Lagrangian surface signatures locate significantly more of the strongest displacement features and the difference in the expected displacements relative to Eulerian ones increases with the length of the time interval considered. Ensemble analysis of forecasts from the Mediterranean model demonstrates that the Lagrangian surface signatures can be used to identify regions of strongest downward vertical displacement even without knowledge of the true ocean state. © 2022, CC BY.

关键词： Surface measurement

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Symptomatic and asymptomatic domoic acid exposure in zebrafish (Danio rerio) revealed distinct non-overlapping gene expression patterns in the brain

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Aquatic Toxicology 2022年 252卷 106310页

作者： Hidayat, Alia S. Lefebvre, Kathi A. MacDonald, James Bammler, Theo Aluru, Neelakanteswar MIT-WHOI Joint Program in Oceanography/Applied Ocean Science & Engineering Cambridge and Woods Hole MA United States Biology Department and Woods Hole Center for Oceans and Human Health Woods Hole Oceanographic Institution Woods Hole MA United States Environmental and Fisheries Science Division Northwest Fisheries Science Center National Marine Fisheries Service NOAA Seattle WA United States Department of Environmental and Occupational Health University of Washington Seattle WA United States

Domoic acid (DA) is a naturally produced neurotoxin synthesized by marine diatoms in the genus Pseudo-nitzschia. DA accumulates in filter-feeders such as shellfish, and can cause severe neurotoxicity when contaminated seafood is ingested, resulting in Amnesic Shellfish Poisoning (ASP) in humans. Overt clinical signs of neurotoxicity include seizures and disorientation. ASP is a significant public health concern, and though seafood regulations have effectively minimized the human risk of severe acute DA poisoning, the effects of exposure at asymptomatic levels are poorly understood. The objective of this study was to determine the effects of exposure to symptomatic and asymptomatic doses of DA on gene expression patterns in the zebrafish brain. We exposed adult zebrafish to either a symptomatic (1.1 ± 0.2 μg DA/g fish) or an asymptomatic (0.31 ± 0.03 µg DA/g fish) dose of DA by intracelomic injection and sampled at 24, 48 and 168 h post-injection. Transcriptional profiling was done using Agilent and Affymetrix microarrays. Our analysis revealed distinct, non-overlapping changes in gene expression between the two doses. We found that the majority of transcriptional changes were observed at 24 h post-injection with both doses. Interestingly, asymptomatic exposure produced more persistent transcriptional effects - in response to symptomatic dose exposure, we observed only one differentially expressed gene one week after exposure, compared to 26 in the asymptomatic dose at the same time (FDR <0.05). GO term analysis revealed that symptomatic DA exposure affected genes associated with peptidyl proline modification and retinoic acid metabolism. Asymptomatic exposure caused differential expression of genes that were associated with GO terms including circadian rhythms and visual system, and also the neuroactive ligand-receptor signaling KEGG pathway. Overall, these results suggest that transcriptional responses are specific to the DA dose and that asymptomatic exposure can

关键词： Domoic acid Excitotoxin Glutamate Harmful algal bloom toxin

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Reprocessing the NEAT Dataset: Preliminary Results

arXiv

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arXiv 2025年

作者： Nugent, C.R. Bauer, J.M. Benitez, O. Blain, M. D’Souza, N. Garimella, S. Goldwater, M. Kim, Y. Larsen, H.C.G. Linder, T. Mackowiak, K. McGinnis, Z. Pan, E. Pedersen, C.C. Sadhwani, P. Spoto, F. Tan, N.J. Vereš, P. Xue, C. Olin College of Engineering 1000 Olin Way NeedhamMA02492 United States Department of Astronomy University of Maryland College ParkMD20742 United States Department of Earth and Space Sciences College of the Canyons Santa ClaritaCA91355 United States MIT-WHOI Joint Program in Applied Ocean Science & Engineering Cambridge and Woods Hole MA United States Department of Applied Ocean Physics & Engineering Woods Hole Oceanographic Institution 266 Woods Hole Road MS #55 Woods HoleMA02543-1050 United States Aalborg University Fibigerstræde 16 Aalborg9220 Denmark Planetary Science Institute TucsonAZ85719 United States Minor Planet Center Smithsonian Astrophysical Observatory 60 Garden Street CambridgeMA02138 United States School of Physical and Chemical Sciences Te Kura Matū University of Canterbury Private Bag 4800 Christchurch8140 New Zealand

We have created a new image analysis pipeline to reprocess images taken by the Near Earth Asteroid Tracking survey and have applied it to ten nights of observations. This work is the first large-scale reprocessing of images from an asteroid discovery survey in which thousands of archived images are re-calibrated, searched for minor planets, and resulting observations are reported to the Minor Planet Center. We describe the software used to extract, calibrate, and clean sources from the images, including specific techniques that accommodate the unique features of these archival images. This pipeline is able to find fainter asteroids than the original pipeline. © 2025, CC BY.

关键词： Asteroids

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