Ocean scientists have dreamed and recently started to realize an ocean observing revolution with autonomous observing platforms and sensors. Critical questions to be answered by such autonomous systems are where, when, and what to sample for optimal information, and how to optimally reach the sampling locations. Definitions, concepts, and progress towards answering these questions using quantitative predictions and fundamental principles are presented. Results in reachability and path planning, adaptive sampling, machine learning, and teaming machines with scientists are overviewed. The integrated use of differential equations and theory from varied disciplines is emphasized. The results provide an inference engine and knowledge base for expert autonomous observing systems. They are showcased using a set of recent at-sea campaigns and realistic simulations. Real-time experiments with identical AUVs in the Buzzards Bay and Vineyard Sound region first show that our predicted time-optimal paths were faster than shortest distance paths. Deterministic and probabilistic reachability and path forecasts issued and validated for gliders and floats in the northern Arabian Sea are then presented. Novel Bayesian adaptive sampling for hypothesis testing and optimal learning are finally shown to forecast the observations most informative to estimate the accuracy of model formulations, the values of ecosystem parameters and dynamic fields, and the presence of Lagrangian Coherent Structures.

A pressing environmental question facing the ocean is the potential impact of possible deep-sea mining activities. This work presents our initial results in developing an ocean and plume modeling system for the Bismark Sea where deep sea mining operations will probably take place. We employ the MSEAS modeling system to both simulate the ocean and to downscale initial conditions from a global system (HYCOM) and tidal forcing from the global TPXO-8 Atlas. We found that at least 1.5 km resolution was needed to adequately resolve the multiscale flow fields. In St. Georges channel, the interaction between the tides, background currents, and underlying density fields increased the subtidal flows. Comparing to historical transport estimates, we showed that tidal forcing is needed to maintain the correct subtidal transport through that Channel. Comparisons with past simulations and measured currents all showed good agreement between the MSEAS hindcasts. Quantitative comparisons made between our hindcasts and independent synoptic ARGO profiles showed that the hindcasts beat persistence by 33% to 50%. These comparisons demonstrated that the MSEAS current estimates were useful for assessing plume advection. Our Lagrangian transport and coherence analyses indicate that the specific location and time of the releases can have a big impact on their dispersal. Our results suggest that ocean mining plumes can be best mitigated by managing releases in accord with such ocean modeling and Lagrangian transport forecasts. Real-time integrated mining-modeling-sampling is likely to provide the most effective mitigation strategies.

Congratulations to Johnathan Hiep Vo on his graduation! Johnathan received an SM from Mechanical Engineering for his research on “Modeling Flow Encountering Abrupt Topography using Hybridizable Discontinuous Galerkin Projection Methods” with our MSEAS group at MIT.

In this work novel high-order hybridizable discontinuous Galerkin (HDG) projection methods are further developed for ocean dynamics and geophysical fluid predictions. We investigate the effects of the HDG stabilization parameter for both the momentum equation as well as tracer diffusion. We also make a correction to our singularity treatment algorithm for nailing down a numerically consistent and unique solution to the pressure Poisson equation with homogeneous Neumann boundary conditions everywhere along the boundary. Extensive numerical results using physically realistic ocean flows are presented to verify the HDG projection methods, including the formation of internal wave beams over a shallow but abrupt seamount, the generation of internal solitary waves from stratified oscillatory flow over steep topography, and the circulation of bottom gravity currents down a slope. Additionally, we investigate the implementation of open boundary conditions for finite element methods and present results in the context of our ocean simulations. Through this work we present the hybridizable discontinuous Galerkin projection methods as a viable and competitive alternative for large-scale, realistic ocean modeling.

Abstract: The increasing interest in exploring the seafloor searching for new sources of minerals in the Area, provoke a series of challenges: legal, technical, environmental and societal. The UNCLOS 1982, the implementation agreements 1994 and 1995 set the legal frameworks for exploration of minerals at the sediments, ridges and seamounts of the world ocean included in the Area (region beyond national jurisdiction). To date the sole Instrument with jurisdiction on the regulation/administration and protection of the seafloor in the Area is the International Seabed Authority (ISA). I present here the advances and gaps of knowledge of the ISA’s efforts towards a solid EIA for the Area. Evidently a worldwide collaboration (academia/public/private institutions) is needed to achieve this goal.

Biography: Sandor Mulsow is a marine geologist whose major research interest is on environmental studies at the sediment-water interface, from shallow to deep sea waters. He has worked in more than 50 different countries on different international projects under the main objective of environmental monitoring of the oceans (water column, biota, and marine sediments), creating capacity and manpower building to undeveloped countries, from Africa to Latin America. Dr. Mulsow has worked at the International Atomic Energy Agency (Monaco), Universidad Austral de Chile (tenured professor), and currently is the Head of the Office of Environmental Management and Mineral Resources of the International Seabed Authority, Jamaica. He develops tools for deep sea monitoring and holds a US patent on one of them. He has created/funded a successful bilingual elementary and high school in Valdivia-Chile, strongly focused on nature and conservation awareness projects.