Shape Animation with Combined Captured and Simulated Dynamics

We present a novel volumetric animation generation framework to create new types of animations from raw 3D surface or point cloud sequence of captured real performances. The framework considers as input time incoherent 3D observations of a moving shape, and is thus particularly suitable for the output of performance capture platforms. In our system, a suitable virtual representation of the actor is built from real captures that allows seamless combination and simulation with virtual external forces and objects, in which the original captured actor can be reshaped, disassembled or reassembled from user-specified virtual physics. Instead of using the dominant surface-based geometric representation of the capture, which is less suitable for volumetric effects, our pipeline exploits Centroidal Voronoi tessellation decompositions as unified volumetric representation of the real captured actor, which we show can be used seamlessly as a building block for all processing stages, from capture and tracking to virtual physic simulation. The representation makes no human specific assumption and can be used to capture and re-simulate the actor with props or other moving scenery elements. We demonstrate the potential of this pipeline for virtual reanimation of a real captured event with various unprecedented volumetric visual effects, such as volumetric distortion, erosion, morphing, gravity pull, or collisions

NTAS 16 sixteenth setting of the NTAS Ocean Reference Station cruise on board RV Endeavor January 21 - February 8, 2017 Narragansett, Rhode Island - San Juan, Puerto Rico

The Northwest Tropical Atlantic Station (NTAS) was established to address the need for accurate air-sea flux estimates and upper ocean measurements in a region with strong sea surface temperature anomalies and the likelihood of significant local air–sea interaction on inter-annual to decadal timescales. The approach is to maintain a surface mooring outfitted for meteorological and oceanographic measurements at a site near 15N, 51W by successive mooring turnarounds. These observations are used to investigate air–sea interaction processes related to climate variability. The NTAS Ocean Reference Station (ORS NTAS) is supported by the National Oceanic and Atmospheric Administration’s (NOAA) Ocean Observing and Monitoring Division. This report documents recovery of the NTAS-15 mooring and deployment of the NTAS-16 mooring. Both moorings used Surlyn foam buoys as the surface element. These buoys were outfitted with two Air–Sea Interaction Meteorology (ASIMET) systems. Each system measures, records, and transmits via Argos satellite the surface meteorological variables necessary to compute air–sea fluxes of heat, moisture and momentum. The upper 160 m of the mooring line were outfitted with oceanographic sensors for the measurement of temperature, salinity and velocity. The mooring turnaround was done by the Upper Ocean Processes Group of the Woods Hole Oceanographic Institution (WHOI), onboard R/V Endeavor (cruise EN590). The cruise took place between January 21 and February 8 2017. The NTAS-16 mooring was deployed on January 30, and the NTAS-15 mooring was recovered on January 31. A 24-hour intercomparison period was conducted on January 29 in front of the NTAS 15 buoy, and again on February 1 in front of the NTAS 16 buoy. During the inter-comparisons, data from instrumentation on the buoys, telemetered through Argos satellite system, and the ship’s meteorological and oceanographic measurements were monitored while the ship was stationed 0.2 nm downwind of the buoys. This report describes these operations, as well as other work done on the cruise and some of the pre-cruise buoy preparations. Other operations during EN590 consisted in the recovery and deployment of the Meridional Overturning Variability Experiment (MOVE) Pressure Inverted Echo Sounders (PIES) at two MOVE arrays (MOVE 1 in the east, and MOVE 3 in the west near Guadeloupe). Acoustic downloads of data from (PIES) and subsurface mooring (MOVE1, 3 and 4) were also conducted. MOVE is designed to monitor the integrated deep meridional flow in the tropical North Atlantic.Funding was provided by the National Oceanic and Atmospheric Administration under Grant No. NA14OAR4320158

The thermocline and current structure in subtropical/subpolar basins

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution May 1984Part one of this thesis discusses the structure of the thermocline and the current pattern within a two-layer model. The corresponding flow field is explored as the amount of water in the upper layer is gradually reduced (or as the wind stress is gradually increased). In the model, when the amount of water in the upper layer is less than a first critical value, the lower layer outcrops near the middle of the western boundary. A dynamically consistent picture includes a whole loop of boundary currents, which surround the outcropping zone completely and have quite different structures. In addition to the boundary currents found in previous models, there is an isolated western boundary current (i.e. bounded on one side by the wall and on the other by a streamline along which the upper layer thickness vanishes), an internal boundary current and possibly isolated northern/southern boundary currents. Within the limitations of the two-layer model, the isolated western boundary current appears to represent the Labrador Current while the internal boundary current may represent the North Atlantic Current. A first baroclinic mode of water mass exchange occurs across the ZWCL (zero-wind-curl-line). When the amount of water in the upper layer is less than a second critical value, the upper layer separates from the eastern wall and becomes a warm water pool in the south-west corner of the basin. Under this warm water pool is the ventilated lower layer. The sea surface density distribution is not specified; it is determined from a consistent dynamical and mass balance. Implicit in this model is the assumption that advection dominates in the mixed layer. The subtropical gyre and the subpolar gyre combine asymmetrically with respect to the ZWCL. Chapter I discusses the case when the lower layer depth is infinite. Chapter II discusses the case when the lower layer depth is finite. In the Addendum the climatological meaning of this two-layer model is discussed. Part two of this thesis concerns the use of a continuously stratified model to represent the thermocline and current structures in subtropical/subpolar basins. The ideal fluid thermocline equation system Is a nonlinear, non-strict hyperbolic system. In an Addendum to Chapter III the mathematical properties of this equation system are studied and a proper way of formulating boundary value problems is discussed. Although the equations are not of standard type, so that no firm conclusions about the existence and uniqueness of solutions have been drawn, some possible approaches to properly posed boundary value problem are suggested. Chapter III presents some simple numerical solutions of the ideal fluid thermocline equation for a subtropical gyre and a subtropical/subpolar basin using one of these approaches. Our model predicts the continuous three dimensional thermocline and current structures in a continuously stratified wind-driven ocean. The upper surface density and Ekman pumping velocity are specified as input data; in addition, the functional form of the potential vorticity is specified. The present model emphasizes the idea that the ideal fluid thermocline model is incomplete. The potential vorticity distribution can not be determined within this idealized model. This suggests that the diffusion and upwelling/downwelling within the western boundary current and the outcropping zone in the north-west corner are important parts of the entire circulation system.This work was supported by NSF Grant 80-19260-0CE

On the role of the Prandtl number in convection driven by heat sources and sinks

We report on a numerical study of turbulent convection driven by a combination of internal heat sources and sinks. Motivated by a recent experimental realisation (Lepot et al. 2018), we focus on the situation where the cooling is uniform, while the internal heating is localised near the bottom boundary, over approximately one tenth of the domain height. We obtain scaling laws $Nu \sim Ra^\gamma Pr^\chi$ for the heat transfer as measured by the Nusselt number $Nu$ expressed as a function of the Rayleigh number $Ra$ and the Prandtl number $Pr$. After confirming the experimental value $\gamma\approx 1/2$ for the dependence on $Ra$, we identify several regimes of dependence on $Pr$. For a stress-free bottom surface and within a range as broad as $Pr \in [0.003, 10]$, we observe the exponent $\chi\approx 1/2$, in agreement with Spiegel's mixing length theory. For a no-slip bottom surface we observe a transition from $\chi\approx 1/2$ for $Pr \leq 0.04$ to $\chi\approx 1/6$ for $Pr \geq 0.04$, in agreement with scaling predictions by Bouillaut et al. The latter scaling regime stems from heat accumulation in the stagnant layer adjacent to a no-slip bottom boundary, which we characterise by comparing the local contributions of diffusive and convective thermal fluxes.Comment: 11 pages, 3 figures, in press for J. Fluid Mec

Tuning Nanocrystal Surface Depletion by Controlling Dopant Distribution as a Route Toward Enhanced Film Conductivity

Electron conduction through bare metal oxide nanocrystal (NC) films is hindered by surface depletion regions resulting from the presence of surface states. We control the radial dopant distribution in tin-doped indium oxide (ITO) NCs as a means to manipulate the NC depletion width. We find in films of ITO NCs of equal overall dopant concentration that those with dopant-enriched surfaces show decreased depletion width and increased conductivity. Variable temperature conductivity data shows electron localization length increases and associated depletion width decreases monotonically with increased density of dopants near the NC surface. We calculate band profiles for NCs of differing radial dopant distributions and, in agreement with variable temperature conductivity fits, find NCs with dopant-enriched surfaces have narrower depletion widths and longer localization lengths than those with dopant-enriched cores. Following amelioration of NC surface depletion by atomic layer deposition of alumina, all films of equal overall dopant concentration have similar conductivity. Variable temperature conductivity measurements on alumina-capped films indicate all films behave as granular metals. Herein, we conclude that dopant-enriched surfaces decrease the near-surface depletion region, which directly increases the electron localization length and conductivity of NC films

The Northwest Tropical Atlantic Station (NTAS) : NTAS-17 mooring turnaround cruise report cruise on board FV Pisces May 30 – June 21, 2018 Mayport, FL, USA – Morehead City, NC, USA

The Northwest Tropical Atlantic Station (NTAS) was established to address the need for accurate air-sea flux estimates and upper ocean measurements in a region with strong sea surface temperature anomalies and the likelihood of significant local air–sea interaction on interannual to decadal timescales. The approach is to maintain a surface mooring outfitted for meteorological and oceanographic measurements at a site near 15N, 51W by successive mooring turnarounds. These observations are used to investigate air–sea interaction processes related to climate variability. The NTAS Ocean Reference Station (ORS NTAS) is supported by the National Oceanic and Atmospheric Administration’s (NOAA) Ocean Observing and Monitoring Division. This report documents recovery of the NTAS-16 mooring and deployment of the NTAS-17 mooring at the same site. Both moorings used Surlyn foam buoys as the surface element. These buoys were outfitted with two Air–Sea Interaction Meteorology (ASIMET) systems. Each system measures, records, and transmits via Argos satellite the surface meteorological variables necessary to compute air–sea fluxes of heat, moisture and momentum. The upper 160 m of the mooring line were outfitted with oceanographic sensors for the measurement of temperature, salinity and velocity. The mooring turnaround was done by the Upper Ocean Processes Group of the Woods Hole Oceanographic Institution (WHOI), onboard F/V Pisces, Cruise PC-18-03. The cruise took place between May 30 and June 21 2018. The NTAS-17 mooring was deployed on June 10, and the NTAS-16 mooring was recovered on June 12. No inter-comparison between ship and buoys was performed on this cruise. This report describes these operations, as well as other work done on the cruise and some of the pre-cruise buoy preparations. Other operations during PC-18-03 consisted in the recovery and deployment of the Meridional Overturning Variability Experiment (MOVE) subsurface moorings array (MOVE 1 in the east, and MOVE 3 and 4 in the west near Guadeloupe). Acoustic download of data from Pressure Inverted Echo Sounders (PIES) was also conducted. MOVE is designed to monitor the integrated deep meridional flow in the tropical North Atlantic.Funding was provided by the National Oceanic and Atmospheric Administration under Grant No. NA14OAR432015

The Northwest Tropical Atlantic Station (NTAS) : NTAS-14 mooring turnaround cruise report

The Northwest Tropical Atlantic Station (NTAS) was established to address the need for accurate air-sea flux estimates and upper ocean measurements in a region with strong sea surface temperature anomalies and the likelihood of significant local air-sea interaction on interannual to decadal timescales. The approach is to maintain a surface mooring outfitted for meteorological and oceanographic measurements at a site near 15°N, 51°W by successive mooring turnarounds. These observations are used to investigate air-sea interaction processes related to climate variability. The NTAS Ocean Reference Station (ORS NTAS) is supported by the National Oceanic and Atmospheric Administration’s (NOAA) Climate Observation Program. This report documents recovery of the NTAS-13 mooring and deployment of the NTAS-14 mooring at the same site. Both moorings used Surlyn foam buoys as the surface element. These buoys were outfitted with two Air-Sea Interaction Meteorology (ASIMET) systems. Each system measures, records, and transmits via Argos satellite the surface meteorological variables necessary to compute air-sea fluxes of heat, moisture and momentum. The upper 160 m of the mooring line were outfitted with oceanographic sensors for the measurement of temperature, salinity and velocity. The mooring turnaround was done by the Upper Ocean Processes Group of the Woods Hole Oceanographic Institution (WHOI), onboard R/V Endeavor, Cruise EN549. The cruise took place between December 5 and 21 December 2014. The NTAS-14 mooring was deployed on December 13, and immediately followed by a 36-hour intercomparison period during which data from the buoy, telemetered through Argos satellite system, and the ship’s meteorological and oceanographic data were monitored. The NTAS-13 buoy had parted on September 23 and was recovered on October 28 while drifting freely near Martinique. The rest of the mooring, which had fallen to the seafloor was recovered during EN549, on December 17. This report describes these operations, as well as other work done on the cruise and some of the pre-cruise buoy preparations. Other operations during EN549 consisted in the recovery and deployment of Pressure Inverted Echo Sounders (PIES) and the acoustic download of data from PIES and subsurface moorings that are part of the Meridional Overturning Variability Experiment (MOVE) array. MOVE is designed to monitor the integrated deep meridional flow in the tropical North Atlantic. Two Argo floats were also deployed during the cruise on behalf of the Argo group at WHOI.Funding was provided by the National Oceanic and Atmospheric Administration under Grant No. NA14OAR4320158

Sediment provenance in the Baker-Martínez fjord system (Chile, 48°s) indicated by magnetic susceptibility and inorganic geochemistry

Fjord sediments are increasingly used as high-resolution archives of climate and environmental change, including variations in glacier mass balance and terrestrial hydrology. To accurately interpret such sediment records, it is crucial to comprehend sediment transport processes and determine sediment provenance. With this in mind, our main objective is to identify cost-effective parameters that can be used to reconstruct relative variations in the origin of sediments deposited in the Baker-Martínez fjord system, which is located between the Northern (NPI) and Southern (SPI) Patagonian Icefields. We focus on estimating the proportions of sediment derived from each icefield, taking advantage of the clearly distinct lithologies that underlie NPI (Patagonian Batholith) and SPI (Eastern Andean Metamorphic Complex) glaciers. The magnetic susceptibility and inorganic geochemistry of 21 surface sediment samples collected along the fjord system and that of suspended sediment samples from the four main rivers that discharge at its heads were investigated. Results indicate that sediments derived from the NPI are characterized by higher magnetic susceptibility and log(Ti/Al) values than those from the SPI, reflecting the mafic nature of the batholith. In fjords that receive contributions from both the NPI and SPI, magnetic susceptibility and log(Ti/Al) primarily reflect sediment provenance. In fjords receiving sediment from only one icefield, however, these parameters are positively correlated with grain size and reflect the progressive settling of particles from the surficial plume. Our results suggest that magnetic susceptibility and log(Ti/Al) can be used to reconstruct sediment provenance within the Baker-Martínez fjord system, but that only log(Ti/Al) can provide quantitative estimates of the proportions of sediment derived from each icefield. Ultimately, applying these provenance indicators to long sediment cores from the Baker-Martínez fjord system could allow reconstructing relative variations in sediment input from each icefield, which may in turn be interpreted as changes in river discharge and/or glacier mass balance