Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Wind

Discipline
Institution
Publication Year
Publication
Publication Type
File Type

Articles 181 - 210 of 2527

Full-Text Articles in Entire DC Network

The Spatial Distribution Of The Japanese Beetle, Popillia Japonica, In Soybean Fields, Stacey Sara, Emily Mccallen, Paul Switzer Jan 2013

The Spatial Distribution Of The Japanese Beetle, Popillia Japonica, In Soybean Fields, Stacey Sara, Emily Mccallen, Paul Switzer

Faculty Research & Creative Activity

The Japanese beetle, Popillia japonica Newman (Coleoptera: Scarabaeidae), is a serious pest of many agricultural and horticultural plants. Relatively little research has investigated the distributions of Japanese beetles in agricultural fields, and this lack of information makes pest management more difficult. In the present study, the spatial distribution of Japanese beetles in soybean fields was examined. Specifically, how the distribution and abundance of beetles was affected by distance from an edge, edge direction, and edge type was examined. An edge effect for density was discovered; beetle numbers decreased significantly with increasing distance from the field edge. The east and south …

Go to article

Ordway Weather And Water Data 2013, Macalester College Jan 2013

Ordway Weather And Water Data 2013, Macalester College

Ordway Weather Data

Contains daily readings for the year indicated. The values include: PAR umol/s/m2, avg wind dir degree, avg windspeed mph, Avg Max Windspeed mph, Avg airtemp C, Avg RH %, Avg BP mmHg, Avg DailyRain in, Avg Rain Duration sec, Avg RainIntensity in/h, Avg Water Temp F, Avg sp cond mS/cm, avg pH, Avg Turb NTU+, Avg ODOSat %, Avg ODO mg/L, Water station PAR umol/s/m2, Avg Water Level m. File format: CSV.

Go to article

The Spatial Distribution Of The Japanese Beetle, Popillia Japonica, In Soybean Fields, Stacey A. Sara, Emily B. Mccallen, Paul V. Switzer Jan 2013

The Spatial Distribution Of The Japanese Beetle, Popillia Japonica, In Soybean Fields, Stacey A. Sara, Emily B. Mccallen, Paul V. Switzer

Faculty Research & Creative Activity

The Japanese beetle, Popillia japonica Newman (Coleoptera: Scarabaeidae), is a serious pest of many agricultural and horticultural plants. Relatively little research has investigated the distributions of Japanese beetles in agricultural fields, and this lack of information makes pest management more difficult. In the present study, the spatial distribution of Japanese beetles in soybean fields was examined. Specifically, how the distribution and abundance of beetles was affected by distance from an edge, edge direction, and edge type was examined. An edge effect for density was discovered; beetle numbers decreased significantly with increasing distance from the field edge. The east and south …

Go to article

Influence Of Larval Behavior On Transport And Population Connectivity In A Realistic Simulation Of The California Current System, Patrick T. Drake, Christopher A. Edwards, Steven G. Morgan, Edward P. Dever Jan 2013

Influence Of Larval Behavior On Transport And Population Connectivity In A Realistic Simulation Of The California Current System, Patrick T. Drake, Christopher A. Edwards, Steven G. Morgan, Edward P. Dever

Journal of Marine Research

Using an implementation of the Region Ocean Modeling System, we investigate the influence of larval vertical swimming on spring dispersal for nearshore invertebrate species in the California Current System (CCS), with a focus on central California and the Bodega Bay area. Larvae are given a suite of idealized behaviors designed to reveal the importance of the surface boundary layer (SBL) to transport and settlement. Larvae remain near 5 m, 30 m, or transition between these depths using various strategies, including diel vertical migration (DVM) and ontogenetic vertical migration. Some behaviors result in modeled densities qualitatively similar to observed cross-shelf larval …

Go to article

Antimicrobial Resistance To 14 Antimicrobials In Marine Coastal Waters Around Northern Ireland: Use Of The Novel Relative Resistance Index As A Marker Of Ecological Status, Peter J. A. Moore, Juluri R. Rao, B. Cherie Millar, Colin E. Goldsmith, Wilson A. Coulter, John E. Moore Jan 2013

Antimicrobial Resistance To 14 Antimicrobials In Marine Coastal Waters Around Northern Ireland: Use Of The Novel Relative Resistance Index As A Marker Of Ecological Status, Peter J. A. Moore, Juluri R. Rao, B. Cherie Millar, Colin E. Goldsmith, Wilson A. Coulter, John E. Moore

Journal of Marine Research

Relatively little work has been published on the incidence of antibiotic resistance (ABR) in the marine microbiological environment, which is of importance to animal (fish, mammals, birds) health, zoonotic transmission, distribution of ABR bacteria with oceanic drift, and ultimately human health. A study was performed to determine the diversity of total ABR (intrinsic and acquired resistance) in marine bacteria in shallow coastal waters surrounding Northern Ireland through the use of a novel Relative Resistance Index (RRI) as a surrogate marker for ecological change, particularly in comparing marine water in commercial versus non-commercial sites. Total antibiotic resistance was observed to varying …

Go to article

Circulation And Cross-Shelf Transport In The Florida Big Bend, Austin C. Todd, Steven L. Morey, Eric P. Chassignet Jan 2013

Circulation And Cross-Shelf Transport In The Florida Big Bend, Austin C. Todd, Steven L. Morey, Eric P. Chassignet

Journal of Marine Research

The Florida Big Bend region in the northeastern Gulf of Mexico contains both spawning sites and nursery habitats for a variety of economically valuable marine species. One species, the gag grouper (Mycteroperca microlepis), relies on the shelf circulation to distribute larvae from shelf-break spawning grounds to coastal sea-grass nurseries each spring. Therefore, identifying the dominant circulation features and physical mechanisms that contribute to cross-shelf transport during the springtime is a necessary step in understanding the variation of the abundance of this reef fish. The mean circulation features and onshore transport pathways are investigated using a numerical ocean model …

Go to article

Eddy Induced Kuroshio Intrusions Onto The Continental Shelf Of The East China Sea, Pedro Vélez-Belchí, Luca R. Centurioni, Dong-Kyu Lee, Sen Jan, Pearn P. Niiler Jan 2013

Eddy Induced Kuroshio Intrusions Onto The Continental Shelf Of The East China Sea, Pedro Vélez-Belchí, Luca R. Centurioni, Dong-Kyu Lee, Sen Jan, Pearn P. Niiler

Journal of Marine Research

The Kuroshio is known to intrude onto the continental shelf in the southern East China Sea (ECS) northeast of Taiwan. Two types of intrusions are observed: large and small, depending on how far the Kuroshio penetrates onto the ECS continental shelf, and on the location where it crosses the shelf break. This study demonstrates that cyclonic eddies from the western Pacific induce some of these large Kuroshio intrusions. The large intrusions are identified from more than 20 years of drifter tracks archived in the Global Drifter Program historical database and from weekly and biweekly drifter deployments carried out between April …

Go to article

Numerical Study Of Cold Dome Variability Induced By Typhoon Morakot (2009) Off Northeastern Taiwan, Yaling Tsai, Ching-Sheng Chern, Sen Jan, Joe Wang Jan 2013

Numerical Study Of Cold Dome Variability Induced By Typhoon Morakot (2009) Off Northeastern Taiwan, Yaling Tsai, Ching-Sheng Chern, Sen Jan, Joe Wang

Journal of Marine Research

The ocean response to the passage of Typhoon Morakot (2009) near the continental shelf of the East China Sea off northeastern Taiwan was evaluated using a numerical ocean model to clarify how the permanent upwelling feature in this region was changed during this storm event. Several studies have identified the presence of the Kuroshio subsurface water in this Cold Dome region, which results from the interactions among the monsoon, the Kuroshio and the shelf topography. This study shows how tropical cyclone Morakot's passage quickly disturbed the circulation around Taiwan and induced a short-period intrusion of the Kuroshio water onto the …

Go to article

An Experimental Testbed For Multi-Robot Tracking Of Manifolds And Coherent Structures In Flows, Matthew Michini, Kenneth Mallory, Dennis Larkin, M. Ani Hsieh, Eric Forgoston, Philip A. Yecko Jan 2013

An Experimental Testbed For Multi-Robot Tracking Of Manifolds And Coherent Structures In Flows, Matthew Michini, Kenneth Mallory, Dennis Larkin, M. Ani Hsieh, Eric Forgoston, Philip A. Yecko

Department of Applied Mathematics and Statistics Faculty Scholarship and Creative Works

In this paper, we describe the development of an experimental testbed capable of producing controllable ocean-like flows in a laboratory setting. The objective is to develop a testbed to evaluate multi-robot strategies for tracking manifolds and Lagrangian coherent structures (LCS) in the ocean. Recent theoretical results have shown that LCS coincide with minimum energy and minimum time optimal paths for autonomous vehicles in the ocean. Furthermore, knowledge of these structures enables the prediction and estimation of the underlying fluid dynamics. The testbed is a scaled flow tank capable of generating complex and controlled quasi-2D flow fields that exhibit wind-driven doublegyre …

Go to article

Spatial Distribution Of Alitta Virens And Clymenella Torquata With Respect To Rigid Boundaries In Mud And Sand, Kevin T. Du Clos, Sara M. Lindsay, Peter A. Jumars Jan 2013

Spatial Distribution Of Alitta Virens And Clymenella Torquata With Respect To Rigid Boundaries In Mud And Sand, Kevin T. Du Clos, Sara M. Lindsay, Peter A. Jumars

Journal of Marine Research

Recent advances in understanding of sediment material properties and of burrowing mechanics suggest likely differences in the behavior of organisms burrowing in mud and sand. The path of least resistance in the mud may lead an infaunal organism to burrow along a rigid wall. By contrast, in sand, force chains may prevent a burrowing organism from reaching a rigid wall. Burrowing in mud occurs primarily by the propagation of cracks. Cracks, and hence burrows, tend to propagate along rigid walls. In sand, force chains comprise collections of particles that experience much more stress than their neighbors. Stress chains tend to …

Go to article

Instability Of A Tidal Mixing Front In The Presence Of Realistic Tides And Mixing, K. H. Brink Jan 2013

Instability Of A Tidal Mixing Front In The Presence Of Realistic Tides And Mixing, K. H. Brink

Journal of Marine Research

Instability and lateral eddy fluxes associated with a tidal mixing front are studied using idealized primitive equation numerical model runs. The front itself develops as a result of turbulence associated with imposed tidal currents over a sloping bottom. Thus, the model includes realistic levels of turbulence and time-dependence in the base-state conditions. In all of the 21 configurations considered, the front is unstable to fluctuations that usually draw energy primarily from the potential energy pool. Scalings are developed to parameterize a) the location of the tidal mixing front; b) the eddy kinetic energy; and c) the lateral eddy coefficients. In …

Go to article

Nutrient Supply In The Southern East China Sea After Typhoon Morakot, Chin-Chang Hung, Chih-Ching Chung, Gwo-Ching Gong, Sen Jan, Yaling Tsai, Kuo-Shu Chen, Wen Chen Chou, Ming-An Lee, Yi Chang, Meng-Hsien Chen, Wen-Rong Yang, Chiung-Jung Tseng, Glen Gawarkiewicz Jan 2013

Nutrient Supply In The Southern East China Sea After Typhoon Morakot, Chin-Chang Hung, Chih-Ching Chung, Gwo-Ching Gong, Sen Jan, Yaling Tsai, Kuo-Shu Chen, Wen Chen Chou, Ming-An Lee, Yi Chang, Meng-Hsien Chen, Wen-Rong Yang, Chiung-Jung Tseng, Glen Gawarkiewicz

Journal of Marine Research

Recent studies show that typhoons have profound effects on phytoplankton assemblages along their tracks, but it is difficult to quantitatively estimate nutrient supply after a typhoon's passage due to a lack of nutrient information before and after the arrival of a typhoon. During the passage of Typhoon Morakot (July 22 to Aug. 26, 2009), we conducted pre- and post-typhoon field cruises to study nutrient supply in the Southern East China Sea (SECS). The results showed nitrate and phosphate supplies to the water column in the SECS after the typhoon's passage were 5.6 × 1011 g-N/day and 7.8 × 10 …

Go to article

Development And Evaluation Of New Algorithms For The Retrieval Of Wind And Internal Wave Parameters From Shipborne Marine Radar Data, Björn Lund Nov 2012

Development And Evaluation Of New Algorithms For The Retrieval Of Wind And Internal Wave Parameters From Shipborne Marine Radar Data, Björn Lund

Open Access Dissertations

The goal of this work is to develop and evaluate techniques for the retrieval of wind and internal wave (IW) information from marine X-band radar data. While ocean wind measurements are crucial for the transfer of energy and momentum across the air-sea interface, IWs play an important role in tidal energy transport. Marine radars work by transmitting microwave energy from a rotating antenna that also measures the backscatter. The radar backscatter from the sea surface is controlled by the wind-generated small ripple waves through the Bragg-scattering mechanism. Surface winds are thus the dominant factor for generating the radar backscatter. The …

Go to article

A Climatological Analysis Of The Warm-Season Wind Regimes Of The Beaufort/Chukchi Seas Coasts, William J. Baule Jul 2012

A Climatological Analysis Of The Warm-Season Wind Regimes Of The Beaufort/Chukchi Seas Coasts, William J. Baule

School of Natural Resources: Dissertations, Theses, and Student Research

Climate records for wind speed, wind direction, and temperature are analyzed for the period from 1979-2009 for the Beaufort/Chukchi Seas region of the Arctic. Wind records have historically been subject to far fewer analyses than other meteorological variables, such as temperature or precipitation. This is particularly true for data sparse regions. Data were collected for a large area in the Beaufort/Chukchi Seas region, which includes portions of Russia, the United States, and Canada. Data from 250 stations were collected from a variety of networks throughout the region and uniformly quality controlled. Eight long-term stations were identified for data completeness and …

Go to article

Viewshed Analysis Of Proposed Wind Farms In Maine, Michael Stephens, Colin Cummings Apr 2012

Viewshed Analysis Of Proposed Wind Farms In Maine, Michael Stephens, Colin Cummings

Atlas of Maine

Wind energy has become a rapidly growing source of renewable electricity; world generating capacity is growing at 20-30% per year (IEA, 2008). Wind offers a fantastic opportunity for clean energy generation in Maine, and will support local community economies. However, the turbines that produce this clean energy typically stand over 250 feet tall and can be seen on their mountaintop perches for miles. Many consider them to be visually intrusive and fight to stop wind farm projects in their planning stages (Curtis, 2011). Maine has numerous wind farms already in operation, with many more in the planning and proposal stages …

Go to article

The Air-Sea Transformation And Residual Overturning Circulation Within The Nordic Seas, Pål Erik Isachsen, Ole Anders Nøst Jan 2012

The Air-Sea Transformation And Residual Overturning Circulation Within The Nordic Seas, Pål Erik Isachsen, Ole Anders Nøst

Journal of Marine Research

The residual diapycnal overturning circulation through interior regions of the Nordic Seas is diagnosed. The mean flow is estimated from Ekman dynamics and from the thermal wind relation with reference level velocities deduced from observations and from simplified theory. Eddy-induced transport is estimated from a GM-type parameterization which includes top and bottom boundary layers. The contributions from the Eulerian mean and eddy-induced transport are then compared to the annual-mean air – sea density transformation over the Nordic Seas. The calculations suggest that the mean flow overturning may explain up to 25% of the observed air – sea transformation in the …

Go to article

The Impact Of Ambient Stratification On Freshwater Transport In A River Plume, Yan Jia, Alexander Yankovsky Jan 2012

The Impact Of Ambient Stratification On Freshwater Transport In A River Plume, Yan Jia, Alexander Yankovsky

Journal of Marine Research

The influence of ambient stratification on the river plume dynamics is studied using the Regional Ocean Modeling System (ROMS). The shelf flow is thermally stratified and retains a 15-m deep upper mixed layer. A buoyant inflow into the model domain is systematically varied so that both surface-advected and bottom-advected buoyant plumes are formed. The resulting buoyant plumes are compared with the corresponding numerical solutions when the ambient shelf flow is not stratified. Surface-advected plumes spread on top of the thermocline and are not affected by the ambient stratification. Bottom-advected plumes on the other hand interact with the ambient stratification by …

Go to article

Deep Circulation Within The Argentine Basin, Joseph L. Reid Jan 2012

Deep Circulation Within The Argentine Basin, Joseph L. Reid

Journal of Marine Research

The total transport in the South Atlantic Ocean (Fig. 1) consists of an anticyclonic gyre that reaches from the equator to about 50°S, and south of 40°S two cyclonic turns from the Circumpolar Current and Weddell Sea, west and east of the anticyclonic gyre. This figure has been changed very slightly between 40°S and 50°S from the figure shown in Reid (1994)...

Go to article

Long-Term Patterns Of An Estuarine Pathogen Along A Salinity Gradient, David Bushek, Susan E. Ford, Iris Burt Jan 2012

Long-Term Patterns Of An Estuarine Pathogen Along A Salinity Gradient, David Bushek, Susan E. Ford, Iris Burt

Journal of Marine Research

Parasitic, disease-causing pathogens can exert strong control over marine populations yet few long-term studies exist that describe these relationships. Understanding the connections to long-term large-scale processes relative to local short-term processes should facilitate better planning for disease impacts in the management of marine resources. We describe a 21-yr dataset of dermo disease (Perkinsus marinus) in eastern oysters (Crassostrea virginica) in Delaware Bay, USA. Analyses indicated (1) a strong positive association between disease and mortality that was non-linear and defined by thresholds, (2) a clear spatial gradient of increasing disease and mortality with increasing salinity, (3) an …

Go to article

An Introduction To Ecology Of Infectious Diseases – Oysters And Estuaries, Eileen E. Hofmann, Susan E. Ford Jan 2012

An Introduction To Ecology Of Infectious Diseases – Oysters And Estuaries, Eileen E. Hofmann, Susan E. Ford

Journal of Marine Research

Infectious diseases are recognized as an important factor regulating marine ecosystems (Harvell et al., 1999, 2002, 2004; Porter et al., 2001; McCallum et al., 2004; Ward and Lafferty, 2004; Stewart et al., 2008; Bienfang et al., 2011). Many of the organisms affected by marine diseases have important ecological roles in estuarine and coastal environments and some are also commercially important. Outbreaks of infectious diseases in these environments, referred to as epizootics, can produce significant population declines and extinctions, both of which threaten biodiversity, food web interactions, and ecosystem productivity (Harvell et al., 2002, 2004)...

Go to article

Can Oysters Crassostrea Virginica Develop Resistance To Dermo Disease In The Field: The Impediment Posed By Climate Cycles, Eric N. Powell, John M. Klinck, Ximing Guo, Eileen E. Hofmann, Susan E. Ford, David Bushek Jan 2012

Can Oysters Crassostrea Virginica Develop Resistance To Dermo Disease In The Field: The Impediment Posed By Climate Cycles, Eric N. Powell, John M. Klinck, Ximing Guo, Eileen E. Hofmann, Susan E. Ford, David Bushek

Journal of Marine Research

Populations of eastern oysters, Crassostrea virginica, are commonly limited by mortality from dermo disease. Little development of resistance to Perkinsus marinus, the dermo pathogen, has occurred, despite the high mortality rates and frequency of epizootics. Can the tendency of the parasite to exhibit cyclic epizootics limit the oyster's response to the disease despite the presence of alleles apparently conferring disease resistance? We utilize a gene-based population dynamics model to simulate the development of disease resistance in Crassostrea virginica populations exposed to cyclic mortality encompassing periodicities expected of dermo disease over the geographic range at which epizootics have been …

Go to article

Circulation And Water Properties And Their Relationship To The Oyster Disease Msx In Delaware Bay, Zhiren Wang, Dale B. Haidvogel, David Bushek, Susan E. Ford, Eileen E. Hofmann, Eric N. Powell, John Wilkin Jan 2012

Circulation And Water Properties And Their Relationship To The Oyster Disease Msx In Delaware Bay, Zhiren Wang, Dale B. Haidvogel, David Bushek, Susan E. Ford, Eileen E. Hofmann, Eric N. Powell, John Wilkin

Journal of Marine Research

We apply a high-resolution hydro-dynamical model to investigate the role of physical factors influencing infection prevalence of Haplosporidium nelsoni, causative agent of MSX disease in the eastern oyster (Crassostrea virginica), in Delaware Bay, USA. Validation studies conducted for the years 2000 and 2010–2011 confirm that the model, based upon the Regional Ocean Modeling System, has significant skill in the recovery of observed water level, temperature, salinity, and velocity. Multi-year simulations are performed for periods representing temporal and spatial variations in H. nelsoni infection prevalence (1974–76, 1979–81, 1984–86, 1990–92, and 2006–09) to assess the degree to which the …

Go to article

Spatial And Temporal Variability Of Disease Refuges In An Estuary: Implications For The Development Of Resistance, Susan E. Ford, Emily Scarpa, David Bushek Jan 2012

Spatial And Temporal Variability Of Disease Refuges In An Estuary: Implications For The Development Of Resistance, Susan E. Ford, Emily Scarpa, David Bushek

Journal of Marine Research

Although the concept of genetic refuge has long been employed in ecological and paleoecological context, it has only rarely been used to identify regions where organisms are protected from diseases that affect the rest of a population. The refuges harbor individuals that have not been exposed to selective mortality and remain susceptible to the disease. They represent a reservoir of susceptibility alleles that can mix with those from resistant survivors of disease and can retard the development of resistance in the population as a whole. Two water-borne protistan parasites affect oysters along the east coast of the United States: Haplosporidium …

Go to article

Primary And New Production In The Thermocline Ridge Region Of The Southern Indian Ocean During The Summer Monsoon, Naveen Gandhi, R. Ramesh, S. Prakash, Sharon Noronha, N. Anilkumar Jan 2012

Primary And New Production In The Thermocline Ridge Region Of The Southern Indian Ocean During The Summer Monsoon, Naveen Gandhi, R. Ramesh, S. Prakash, Sharon Noronha, N. Anilkumar

Journal of Marine Research

New and primary production, measured using 15N and 13C tracers, integrated over the euphotic zone (mostly upper 80–100 m) varied from 7.5 to 14.1 mmol N m–2d–1(average 10.8 mmol N m–2d–1) and 2.7 to 17.7 mmol C m–2d–1 (average 11.3 mmol C m–2d–1), respectively, in the tropical India Ocean (TIO). Shoaling of thermocline in the thermocline ridge located in the tropical Indian Ocean (TR) influences new and total productivity by supplying nutrients to the upper layers. At the same time, N-limited conditions prevail …

Go to article

Geostrophic Ocean Currents And Freshwater Fluxes Across The Canadian Polar Shelf Via Nares Strait, Berit Rabe, Helen L. Johnson, Andreas Münchow, Humfrey Melling Jan 2012

Geostrophic Ocean Currents And Freshwater Fluxes Across The Canadian Polar Shelf Via Nares Strait, Berit Rabe, Helen L. Johnson, Andreas Münchow, Humfrey Melling

Journal of Marine Research

This study discusses geostrophic ocean currents and fluxes through Nares Strait, one of the major straits connecting the Arctic Ocean to the North Atlantic across the Canadian polar shelf. Between 2003 and 2006, instruments were installed on subsea moorings to measure conductivity, temperature, pressure and velocity at high temporal and spatial resolution across the 400-m-deep strait. Here we present estimates of the variable volume and liquid freshwater fluxes, derived by geostrophic calculation, through the fraction of the cross section measured by the array. The array of conductivity-temperature recorders spanned 30 km of a 38-km-wide section between 30- and 200-m depth. …

Go to article

Solar Warming Of Near-Bottom Water Over A Fringing Reef, Judith R. Wells, Jonathan P. Fram, Geno Pawlak Jan 2012

Solar Warming Of Near-Bottom Water Over A Fringing Reef, Judith R. Wells, Jonathan P. Fram, Geno Pawlak

Journal of Marine Research

The Kilo Nalu Observatory is located on the foreslope of a fringing reef on the south shore of Oahu, Hawaii. A cabled node at 12-m depth has enabled continuous real-time temperature observations from a thermistor chain extending from 1 to 7 m above bottom. Data from a 27-month deployment in 2007–2009 reveal repeated instances of subsurface temperature inversions. The usual diurnal pattern shows increases in temperature throughout the water column after sunrise, peaking in the early afternoon. Bottom waters typically warm faster than those at mid-depth, driving an inversion in the thermal profile. The onset and evolution of the inversions …

Go to article

Experimental Assessment Of Particle Mixing Fingerprints In The Deposit-Feeding Bivalve Abra Alba (Wood), Guillaume Bernard, Antoine Grémare, Olivier Maire, Pascal Lecroart, Filip J. R. Meysman, Aurélie Ciutat, Bruno Deflandre, Jean Claude Duchêne Jan 2012

Experimental Assessment Of Particle Mixing Fingerprints In The Deposit-Feeding Bivalve Abra Alba (Wood), Guillaume Bernard, Antoine Grémare, Olivier Maire, Pascal Lecroart, Filip J. R. Meysman, Aurélie Ciutat, Bruno Deflandre, Jean Claude Duchêne

Journal of Marine Research

Particle mixing induced by the deposit-feeding bivalve Abra alba was assessed using a new experimental approach allowing for the tracking of individual particle displacements. This approach combines the adaptation of existing image acquisition techniques with new image analysis software that tracks the position of individual particles. This led to measurements of particle mixing fingerprints, namely the frequency distributions of particle waiting times, and of the characteristics (i.e. direction and length) of their jumps. The validity of this new approach was assessed by comparing the so-measured frequency distributions of jump characteristics with the current qualitative knowledge regarding particle mixing in the …

Go to article

Ordway Weather And Water Data 2012, Macalester College Jan 2012

Ordway Weather And Water Data 2012, Macalester College

Ordway Weather Data

Contains daily readings for the year indicated. The values include: PAR umol/s/m2, avg wind dir degree, avg windspeed mph, Avg Max Windspeed mph, Avg airtemp C, Avg RH %, Avg BP mmHg, Avg DailyRain in, Avg Rain Duration sec, Avg RainIntensity in/h, Avg Water Temp F, Avg sp cond mS/cm, avg pH, Avg Turb NTU+, Avg ODOSat %, Avg ODO mg/L, Water station PAR umol/s/m2, Avg Water Level m. File format: CSV.

Go to article

Eddy Viscosity And Diffusivity In The Modon-Sea Model, Timour Radko Jan 2012

Eddy Viscosity And Diffusivity In The Modon-Sea Model, Timour Radko

Journal of Marine Research

A deterministic model is developed to evaluate and explain the rate of dissipation of momentum in eddying oceanic flows. Theory is based on a classical conceptualization of mesoscale variability – Stern's modon-sea solution – which represents a closely packed array of steady compact dipolar vortices on the barotropic beta-plane. In our model, the periodic modon-sea pattern is subjected to a large-scale perturbation, weakly modulating the amplitude of the individual modons. The asymptotic multiscale analysis makes it possible to explicitly describe the interaction between the modon-sea eddies and the perturbing flow. This interaction results in a systematic weakening of the large-scale …

Go to article

Measuring Overturns With Gliders, S. A. Thorpe Jan 2012

Measuring Overturns With Gliders, S. A. Thorpe

Journal of Marine Research

The accuracy of the estimation of the vertical size of eddies in turbulent stratified shear flows in the ocean from measurements obtained by gliders is examined. It is assumed that gliders move along paths inclined at moderate angles to the horizontal. Comparison is made with measurements by probes falling or lowered vertically through billows resulting from Kelvin-Helmholtz (K-H) or Holmboe instability and through the statically unstable regions formed at early stages of convective breaking of internal waves. The probable errors involved in estimating the overturn scale of a K-H billow along the track of a glider are greatest when the …

Go to article

First Prev Next Last