Turbulent and Transitional Modeling of Drag on Oceanographic Measurement Devices

Abstract

Computational fluid dynamic techniques have been applied to the determination of drag on oceanographic devices (expendable bathythermographs). Such devices, which are used to monitor changes in ocean heat content, provide information that is dependent on their drag coefficient. Inaccuracies in drag calculations can impact the estimation of ocean heating associated with global warming. Traditionally, ocean-heating information was based on experimental correlations which related the depth of the device to the fall time. The relation of time-depth is provided by a fall-rate equation (FRE). It is known that FRE depths are reasonably accurate for ocean environments that match the experiments from which the correlations were developed. For other situations, use of the FRE may lead to depth errors that preclude XBTs as accurate oceanographic devices. Here, a CFD approach has been taken which provides drag coefficients that are used to predict depths independent of an FRE.

A new interpretation of seismic tomography in the southern Dead Sea basin using neural network clustering techniques

“…The combined interpretation of different seismic properties (V p , V s , surface wave velocity, V p /V s , Poisson's ratio), instead of the separate treatment of each property, can be used to better constrain the lithological nature of seismic earth models [e.g., Holbrook et al, 1992;Christensen, 1996;Bauer et al, 2003]. A common approach is to crossplot seismic properties such as V p against V p /V s in order to find clusters which are related with distinct rock types frequently occurring in the studied subsurface region [e.g., Bauer et al, 2003;Paasche et al, 2006]. The remapping of the found clusters into the subsurface model reveals the distribution of the rock types at depth.…”

“…The remapping of the found clusters into the subsurface model reveals the distribution of the rock types at depth. The interpretation can be based on the petrophysical signature of each cluster and comparison with rock properties reported in the literature and by linkage with surface geology or borehole information, if available [Bauer et al, 2003].…”

Multidecadal accumulation of anthropogenic and remineralized dissolved inorganic carbon along the Extended Ellett Line in the northeast Atlantic Ocean

“…These feature a higher O 2 coefficient than the "original" stoichiometry of Redfield et al [1963], which gives À0.768 for R C/O2 and À0.116 for R N/O2 . This higher O 2 coefficient is supported by considerations of the composition of several groups of algal biomolecules [Anderson, 1995]. Although switching between these stoichiometries does create a systematic offset in the results, the size of this offset is no larger than the random uncertainty inherent in the calculations.…”

Increased nuisance flooding along the coasts of the United States due to sea level rise: Past and future

“…High-quality sea surface water level (WL) data, recorded at tide gauges all around the world over the last 100+ years, document a significant globally averaged acceleration in mean SLR of 0.009 mm yr À2 since 1880 and a globally averaged mean SLR of~2.8 mm yr À1 between 1993 and 2009 [Church and White, 2011;Church and White, 2006;Church et al, 2013;Domingues et al, 2008;Merrifield et al, 2013;Watson et al, 2015], while altimetry records suggest an SLR rate of 3.3 ± 0.4 mm yr À1 between 1993 and 2014 [Cazenave et al, 2014]. The rate of SLR over the past decades is an order of magnitude larger than SLR over the past millennia [Milne et al, 2009] and projections of SLR over the 21st century, based on current trajectories of anthropogenic activities and greenhouse gases emissions [Lyu et al, 2014], cannot rule out an increase greater than 1 m [Milne et al, 2009;Rahmstorf, 2007;Nicholls and Cazenave, 2010;Kopp et al, 2014].…”