Wind-driven mixing below the oceanic mixed layer

This study describes the turbulent processes in the upper ocean boundary layer forced by a constant surface stress in the absence of the Coriolis force using large-eddy simulation. The boundary layer that develops has a two-layer structure, a well-mixed layer above a stratified shear layer. The depth of the mixed layer is approximately constant, whereas the depth of the shear layer increases with time. The turbulent momentum flux varies approximately linearly from the surface to the base of the shear layer. There is a maximum in the production of turbulence through shear at the base of the mixed layer. The magnitude of the shear production increases with time. The increase is mainly a result of the increase in the turbulent momentum flux at the base of the mixed layer due to the increase in the depth of the boundary layer. The length scale for the shear turbulence is the boundary layer depth. A simple scaling is proposed for the magnitude of the shear production that depends on the surface forcing and the average mixed layer current. The scaling can be interpreted in terms of the divergence of a mean kinetic energy flux. A simple bulk model of the boundary layer is developed to obtain equations describing the variation of the mixed layer and boundary layer depths with time. The model shows that the rate at which the boundary layer deepens does not depend on the stratification of the thermocline. The bulk model shows that the variation in the mixed layer depth is small as long as the surface buoyancy flux is small

Characteristics of Langmuir Turbulence in the Ocean Mixed Layer

This study uses large-eddy simulation (LES) to investigate the characteristics of Langmuir turbulence through the turbulent kinetic energy (TKE) budget. Based on an analysis of the TKE budget a velocity scale for Langmuir turbulence is proposed. The velocity scale depends on both the friction velocity and the surface Stokes drift associated with the wave field. The scaling leads to unique profiles of nondimensional dissipation rate and velocity component variances when the Stokes drift of the wave field is sufficiently large compared to the surface friction velocity. The existence of such a scaling shows that Langmuir turbulence can be considered as a turbulence regime in its own right, rather than a modification of shear-driven turbulence. Comparisons are made between the LES results and observations, but the lack of information concerning the wave field means these are mainly restricted to comparing profile shapes. The shapes of the LES profiles are consistent with observed profiles. The dissipation length scale for Langmuir turbulence is found to be similar to the dissipation length scale in the shear-driven boundary layer. Beyond this it is not possible to test the proposed scaling directly using available data. Entrainment at the base of the mixed layer is shown to be significantly enhanced over that due to normal shear turbulence

INLAND/OCEAN WATERBORNE TRANSPORTATION INNOVATIONS AND PORT CHARGES

Public Economics,

Harm Reduction Programs: West Virginia vs. United States

Introduction: Harm reduction has been a movement for social justice built on a belief in, and respect for, the rights of people who use drugs. It has been defined as a set of practical strategies and ideas aimed at reducing negative consequences associated with drug use. The U.S. has been experiencing an opioid/heroin epidemic, with significant increases in overdose death among drug users with more than 72,000 Americans having died from drug overdoses in 2017. Methodology: The methodology for this study was a literature review with a semi structured interview with Tina Rameriz of the Kanawha-Charleston Health Department in Charleston, West Virginia. The electronic databases used included EBSCOhost, PubMed, Academic Search Premier, ProQuest, and Google Scholar. Government and medical websites were also used. A total of 47 sources were referenced. Results: The results of the literature review showed that West Virginia had the highest age-adjusted rate of drug related overdose deaths in the nation in 2014. Overdoses claimed more than three out of every 100 fatalities and ranked #1 in drug overdose deaths with a rate of 41.5 deaths per 100,000 people in 2015. West Virginia had a statewide Harm Reduction Coalition that provided support and guidance for any agency interested. States such as Minnesota, North Carolina and Ohio have had better results in implementing harm reduction programs. An opportunity of harm reduction programs was the creation of the drug Naloxone. Discussion/Conclusion: This research was not without its limitations. The review suggested that West Virginia has been in fact, behind other states in the U.S. By utilizing several harm reduction programs in the state of West Virginia, this would also create a substantial decrease in the number of HIV and Hepatitis virus spread through needle sharing among injection drug users

The Use of the Blood Lactate Curve to Develop Training Intensity Guidelines for the Sports of Track and Field and Cross-Country

Int J Exerc Sci 5(2) : 148-159, 2012. The purpose of this study was to develop and field test a standardized system of training intensity guidelines for the sport of track and field/cross country, modeled after the standardized system of training intensity guidelines developed, adopted, and in use by U.S.A. Swimming. This study was quantitative and focused on the development and field-testing of standardized training intensity guidelines, based on the blood lactate curve and energy metabolism. The findings showed that as intensity increased so did participants’ blood lactate concentration, heart rate, and ratings of perceived exertion. A Pearson product-moment correlation analysis between the mean values of blood lactate concentration, heart rate, and ratings of perceived exertion, and the corresponding training intensity ranges revealed significant positive correlations between mean blood lactate values (r = 0.99, p \u3c 0.001), mean heart rate (r = 0.96, p \u3c 0.001); and ratings of perceived exertion (r = 0.99, p \u3c 0.005). Correlation analyses between heart rate and measures of blood lactate were positive (r = 0.70, p \u3e 0.05), as were heart rate and ratings of perceived exertion (r = 0.96, p \u3c 0.005). Measures of blood lactate were positively and significantly correlated to ratings of perceived exertion (r = 0.82, p \u3c 0.05). These findings validated the training intensity guidelines model

The carbon life cycle assessment of the production of shelterbelt species in Saskatchewan

Non-Peer ReviewedShelterbelt tree and shrub adoption has been a major landscape management practice on agricultural land in Saskatchewan throughout the 1900s. Shelterbelt trees were distributed to landowners, free of charge, from 1901 to 2002 by the Canadian government's prairie shelterbelt centre, which was located in Indian Head, Saskatchewan. Though the shelterbelt centre at Indian Head closed in 2013, many other shelterbelt centres and forestry nurseries still exist to serve this purpose. Saskpower's Shand Greenhouse, operated out of Estevan, Saskatchewan, provides approximately 500,000 seedlings a year, both free of charge for those eligible and for purchase. Shelterbelt tree and shrubs are important for carbon sequestration and storage efforts within Saskatchewan and Canada, however it is important to note the carbon produced in the production of these seedlings. Using data collected from Shand Greenhouse and an LCA software program (SimaPro), the overall carbon produced by this stage of the shelterbelt life cycle can be determined. With this information, the net carbon balance of shelterbelt production and use will be better understood. This may serve as beneficial information regarding future decision-making for individual landowners and governmental policies regarding the production as well as the removal/retention of shelterbelt trees

Why krill swarms are important to the global climate

Ocean life helps keep atmospheric levels of carbon dioxide lower by taking carbon out of the atmosphere and transporting it to the deep ocean, through sinking particles. Antarctic krill live in the Southern Ocean and gather in huge swarms. Importantly, they produce large, fast-sinking poo (called fecal strings), meaning that we get a rain of poo below these swarms, which takes carbon quickly to the deep ocean. We calculate how krill lower the amount of carbon in the atmosphere by estimating how many krill there are and how many fecal strings each produces. These calculations reveal that Antarctic krill living near sea ice remove 39 million tons of carbon from the surface ocean each year. That is about the same weight as 100 million polar bears! Krill are therefore not only important food for whales and penguins, but also vital engineers of our climate and so they require protection

Fertilizing No-Till Corn

Results of an experiment conducted in 1968 at Princeton, Kentucky on low phosphate soil showed that surface-applied phosphorus was sufficiently available to no-till corn to produce good yields. This experiment was repeated again in the 1969 growing season with the results well in line with those reported for 1968 in Agronomy Research (Misc. 377) pages 41-43

The District Role in Instructional Improvement

Are changing conditions affecting the capacity of districts to provide focus, to coordinate support, and to scale up successful reforms? From a study of the roles played by central office staff members in shaping and supporting instructional reforms in three large urban districts, the authors derive an answer