scholarly journals Modeling Whitecap Fraction with a Wave Model

2016 ◽  
Vol 46 (3) ◽  
pp. 887-894 ◽  
Author(s):  
Brian Scanlon ◽  
Øyvind Breivik ◽  
Jean-Raymond Bidlot ◽  
Peter A. E. M. Janssen ◽  
Adrian H. Callaghan ◽  
...  
Keyword(s):  
High Resolution ◽  
Atlantic Ocean ◽  
Field Experiment ◽  
Linear Relationship ◽  
Source Term ◽  
Wave Model ◽  
Accurate Estimate ◽  
Additional Contribution ◽  
Strong Linear Relationship

AbstractHigh-resolution measurements of actively breaking whitecap fraction (WFA) and total whitecap fraction (WFT) from the Knorr11 field experiment in the Atlantic Ocean are compared with estimates of whitecap fraction modeled from the dissipation source term of the ECMWF wave model. The results reveal a strong linear relationship between model results and observed measurements. This indicates that the wave model dissipation is an accurate estimate of total whitecap fraction. The study also reveals that the dissipation source term is more closely related to WFA than WFT, which includes the additional contribution from maturing (stage B) whitecaps.

MODELING THE SOUTH ATLANTIC OCEAN FROM MEDIUM TO HIGH RESOLUTION

2014 ◽  
Vol 31 (2) ◽  
Author(s):  
Mariela Gabioux ◽  
Vladimir Santos da Costa ◽  
Joao Marcos Azevedo Correia de Souza ◽  
Bruna Faria de Oliveira ◽  
Afonso De Moraes Paiva
Keyword(s):  
High Resolution ◽  
Atlantic Ocean ◽  
Large Scale ◽  
South Atlantic ◽  
Surface Relaxation ◽  
The South ◽  
Small Surface ◽  
Basic Model ◽  
Basic Set ◽  
Set Up

Results of the basic model configuration of the REMO project, a Brazilian approach towards operational oceanography, are discussed. This configuration consists basically of a high-resolution eddy-resolving, 1/12 degree model for the Metarea V, nested in a medium-resolution eddy-permitting, 1/4 degree model of the Atlantic Ocean. These simulations performed with HYCOM model, aim for: a) creating a basic set-up for implementation of assimilation techniques leading to ocean prediction; b) the development of hydrodynamics bases for environmental studies; c) providing boundary conditions for regional domains with increased resolution. The 1/4 degree simulation was able to simulate realistic equatorial and south Atlantic large scale circulation, both the wind-driven and the thermohaline components. The high resolution simulation was able to generate mesoscale and represent well the variability pattern within the Metarea V domain. The BC mean transport values were well represented in the southwestern region (between Vitória-Trinidade sea mount and 29S), in contrast to higher latitudes (higher than 30S) where it was slightly underestimated. Important issues for the simulation of the South Atlantic with high resolution are discussed, like the ideal place for boundaries, improvements in the bathymetric representation and the control of bias SST, by the introducing of a small surface relaxation. In order to make a preliminary assessment of the model behavior when submitted to data assimilation, the Cooper & Haines (1996) method was used to extrapolate SSH anomalies fields to deeper layers every 7 days, with encouraging results.

First report of redbacked cutworm damage to cow cockle [Vaccaria hispanica (Mill.) Rauschert], a potential new crop for western Canada

2011 ◽  
Vol 91 (2) ◽  
pp. 425-428 ◽  
Author(s):  
Christian Willenborg ◽  
Lloyd Dosdall
Keyword(s):  
Linear Relationship ◽  
Seed Yield ◽  
Seed Weight ◽  
Insect Pest ◽  
Western Canada ◽  
First Report ◽  
Euxoa Ochrogaster ◽  
Redbacked Cutworm ◽  
New Crop ◽  
Strong Linear Relationship

Willenborg, C. J. and Dosdall, L. M. 2011. First report of redbacked cutworm damage to cow cockle [ Vaccaria hispanica(Mill.) Rauschert], a potential new crop for western Canada. Can. J. Plant Sci. 91: 425–428. We report the effects of redbacked cutworm Euxoa ochrogaster (Guenée) on cow cockle [Vaccaria hispanica (Mill.) Rauschert] plant height, seed yield, and 1000-seed weight (TSW). Euxoa ochrogaster damage to plots varied considerably among genotypes, with some genotypes exhibiting <10% damage and others >45%. Seed yield also varied significantly among genotypes and exhibited a strong linear relationship with the extent of E. ochrogaster damage. This is the first known report of any insect pest feeding on cow cockle. Results suggest that E. ochrogaster has the potential to cause significant losses in cow cockle crops.

scholarly journals THE BIFURCATION OF THE WESTERN BOUNDARY CURRENT SYSTEM OF THE SOUTH ATLANTIC OCEAN

2014 ◽  
Vol 32 (2) ◽  
pp. 241 ◽  
Author(s):  
Janini Pereira ◽  
Mariela Gabioux ◽  
Martinho Marta Almeida ◽  
Mauro Cirano ◽  
Afonso M. Paiva ◽  
...  
Keyword(s):  
High Resolution ◽  
Atlantic Ocean ◽  
Ocean Circulation ◽  
South Atlantic ◽  
Western Boundary Current ◽  
South Atlantic Ocean ◽  
Western Boundary ◽  
Intermediate Water ◽  
Boundary Current ◽  
The South

ABSTRACT. The results of two high-resolution ocean global circulation models – OGCMs (Hybrid Coordinate Ocean Model – HYCOM and Ocean Circulation andClimate Advanced Modeling Project – OCCAM) are analyzed with a focus on the Western Boundary Current (WBC) system of the South Atlantic Ocean. The volumetransports are calculated for different isopycnal ranges, which represent the most important water masses present in this region. The latitude of bifurcation of the zonalflows reaching the coast, which leads to the formation of southward or northward WBC flow at different depths (or isopycnal levels) is evaluated. For the Tropical Water,bifurcation of the South Equatorial Current occurs at 13◦-15◦S, giving rise to the Brazil Current, for the South Atlantic Central Water this process occurs at 22◦S.For the Antarctic Intermediate Water, bifurcation occurs near 28◦-30◦S, giving rise to a baroclinic unstable WBC at lower latitudes with a very strong vertical shearat mid-depths. Both models give similar results that are also consistent with previous observational studies. Observations of the South Atlantic WBC system havepreviously been sparse, consequently these two independent simulations which are based on realistic high-resolution OGCMs, add confidence to the values presentedin the literature regarding flow bifurcations at the Brazilian coast.Keywords: Southwestern Atlantic circulation, water mass, OCCAM, HYCOM. RESUMO. Resultados de dois modelos globais de alta resolução (HYCOM e OCCAM) são analisados focando o sistema de Corrente de Contorno Oeste do Oceano Atlântico Sul. Os transportes de volume são calculados para diferentes níveis isopicnais que representam as principais massas de água da região. É apresentada a avaliação da latitude de bifurcação do fluxo zonal que atinge a costa, permitindo a formação dos fluxos da Corrente de Contorno Oeste para o sul e para o norte emdiferentes níveis de profundidades (ou isopicnal). Para a Água Tropical, a bifurcação da Corrente Sul Equatorial ocorre entre 13◦-15◦S, originando a Corrente do Brasil, e para a Água Central do Atlântico Sul ocorre em 22◦S. A bifurcação daÁgua Intermediária Antártica ocorre próximo de 28◦-30◦S, dando um aumento na instabilidade baroclínica da Corrente de Contorno Oeste em baixas latitudes e com um forte cisalhamento vertical em profundidades intermediárias. Ambos os modelos apresentamresultados similares e consistentes com estudos observacionais prévios. Considerando que as observações do sistema de Corrente de Contorno Oeste do Atlântico Sul são escassas, essas duas simulações independentes com modelos globais de alta resolução adicionam confiança aos valores apresentados na literatura, relacionadosaos fluxos das bifurcações na costa do Brasil.Palavras-chave: circulação do Atlântico Sudoeste, massas de água, OCCAM, HYCOM.

scholarly journals Analysis of Static and Dynamic E-Reference Content at a Multi-Campus University Shows that Updated Content is Associated with Greater Annual Usage

2016 ◽  
Vol 11 (1) ◽  
pp. 68
Author(s):  
Laura Costello
Keyword(s):  
Regression Analysis ◽  
Linear Relationship ◽  
Reference Book ◽  
Design Case ◽  
Design Case Study ◽  
Undergraduate Programs ◽  
Individual Subscription ◽  
Strong Linear Relationship ◽  
Over Time

A Review of: Lamothe, A. R. (2015). Comparing usage between dynamic and static e-reference collections. Collection Building, 34(3), 78-88. http://dx.doi.org/10.1108/CB-04-2015-0006 Abstract Objective – To discover whether there is a difference in use over time between dynamically updated and changing subscription e-reference titles and collections, and static purchased e-reference titles and collections. Design – Case study. Setting – A multi-campus Canadian university with 9,200 students enrolled in both graduate and undergraduate programs. Subjects – E-reference book packages and individual e-reference titles. Methods – The author compared data from individual e-reference books and packages. First, individual subscription e-reference books that periodically added updated content were compared to individually purchased e-reference books that remained static after purchase. The author then compared two e-reference book packages that provided new and updated content to two static e-reference book packages. The author compared data from patron usage to new content added over time using regression analysis. Main Results – As the library acquired e-reference titles, dynamic title subscriptions added to the collection were associated with 2,246 to 4,635 views per subscription while static title additions were associated with 8 to 123 views per purchase. The author also found that there was a strong linear relationship between views and dynamic titles added to the collection (R2=0.79) and a very weak linear relationship (R2=0.18) with views when static titles are added to the collection. Regression analysis of dynamic e-reference collections revealed that the number of titles added to each collection was strongly associated with views of the material (R2=0.99), while static e-reference collections were less strongly linked (R2=0.43). Conclusion – Dynamic e-reference titles and collections experienced increases in usage each year while static titles and collections experienced decreases in usage. This indicates that collections and titles that offer new content to users each year will continue to see growth in usage while static collections and titles will see maximum usage within a few years and then begin to decline as they get older. Fresh content is strongly associated with usage in e-reference titles, which mirrors the author’s previous work examining static and dynamic content in e-monographs.

Use of Petrifilm™ to Evaluate the Microflora of Frozen Dessert Mixes1

1989 ◽  
Vol 52 (8) ◽  
pp. 549-551 ◽  
Author(s):  
L. B. SMITH ◽  
E. A. ZOTTOLA ◽  
T. L. FOX ◽  
K. CHAUSSE
Keyword(s):  
Linear Relationship ◽  
Raw Milk ◽  
Microbial Populations ◽  
Plate Count ◽  
Standard Methods ◽  
Naturally Occurring ◽  
Colony Forming Units ◽  
Frozen Dessert ◽  
Evaluation Of Data ◽  
Strong Linear Relationship

Ninety vanilla frozen dessert mix samples were analyzed to determine total microbial populations and coliforms present in samples inoculated with a coliform isolated from raw milk. Standard methods agar (SMA, PCA, Difco) and violet red bile agar (VRBA, Difco) as well as Petrifilm™ (PSM, PVRB) were used for plating of samples. Standard VRBA 1:10 method produced significantly higher counts of colony-forming units (CFU) than PVRB 2:3 and VRBA 2:3 methods. VRBA 2:3 colony-forming unit counts were also significantly higher than those on PVRB 2:3, but both methods showed a moderately strong linear relationship. Repeatabilities of all three coliform plating methods (VRBA 1:10, VRBA 2:3, and PVRB 2:3) were acceptably low. Less than 10% of samples plated on SMA and PSM resulted in total aerobic colony-forming units in the countable range, making evaluation of data difficult and resulting in a lack of strong linear relationship between PSM and SMA. An additional 70 local retail store samples containing naturally occurring coliforms were evaluated using PVRB 2:3 and VRBA 1:10 methodology, confirmed in brilliant green lactose bile broth (BGLB, Difco) and compared to standard VRBA 1:10 previously analyzed. All methods were equivalent for mean log coliforms, i.e., 1.38,1.33, and 1.31 for PVRB 2:3, VRBA 2:3, and VRBA 1:10, respectively. Petrifilm™ methods were comparable to standard methods for enumerating coliforms in frozen dairy products, and would be a valid alternative to standard coliform and total plate count methods.

Implementing New Nonlinear Term in Third Generation Wave Models

2014 ◽  
Author(s):  
Odin Gramstad ◽  
Alexander Babanin
Keyword(s):  
Kinetic Equation ◽  
Spread Spectrum ◽  
Time Scale ◽  
Source Term ◽  
Wave Spectrum ◽  
Wave Model ◽  
Third Generation ◽  
Spectral Evolution ◽  
Linear Interaction ◽  
Wavewatch Iii

The non-linear interaction term is one of the three key source functions in every third-generation spectral wave model. An update of physics of this term is discussed. The standard statistical/phase-averaged description of the nonlinear transfer of energy in the wave spectrum (wave-turbulence) is based on Hasselmann’s kinetic equation [1]. In the derivation of the kinetic equation (KE) it is assumed that the evolution takes place on the slow O(ε−4) time scale, where ε is the wave steepness. This excludes the effects of near-resonant quartet interactions that may lead to spectral evolution on the ‘fast’ O(ε−2) time scale. Generalizations of the KE (GKE) that enable description of spectral evolution on the O(ε−2) time scale [2–4] are discussed. The GKE, first solved numerically in [4], is implemented as a source term in the third generation wave model WAVEWATCH-III. The new source term (GKE) is tested and compared to the other nonlinear-interaction source terms in WAVEWATCH-III; the full KE (WRT method) and the approximate DIA method. It is shown that the GKE gives similar results to the KE in the case of a relatively broad banded and directional spread spectrum, while it shows somewhat larger difference in the case of a more narrow banded spectrum with narrower directional distribution. We suggest that the GKE may be a suitable replacement to the KE in situations where ‘fast’ spectral evolution takes place.

scholarly journals High resolution modelling of aerosol dispersion regimes during the CAPITOUL field experiment: from regional to local scale interactions

2011 ◽  
Vol 11 (15) ◽  
pp. 7547-7560 ◽  
Author(s):  
B. Aouizerats ◽  
P. Tulet ◽  
G. Pigeon ◽  
V. Masson ◽  
L. Gomes
Keyword(s):  
Air Quality ◽  
High Resolution ◽  
Field Experiment ◽  
Aerosol Particle ◽  
Pollutant Dispersion ◽  
Local Scale ◽  
Plume Dispersion ◽  
Urban Dynamics ◽  
The Impact ◽  
Resolution Simulation

Abstract. High resolution simulation of complex aerosol particle evolution and gaseous chemistry over an atmospheric urban area is of great interest for understanding air quality and processes. In this context, the CAPITOUL (Canopy and Aerosol Particle Interactions in the Toulouse Urban Layer) field experiment aims at a better understanding of the interactions between the urban dynamics and the aerosol plumes. During a two-day Intensive Observational Period, a numerical model experiment was set up to reproduce the spatial distribution of specific particle pollutants, from the regional scales and the interactions between different cities, to the local scales with specific turbulent structures. Observations show that local dynamics depends on the day-regime, and may lead to different mesoscale dynamical structures. This study focuses on reproducing these fine scale dynamical structures, and investigate the impact on the aerosol plume dispersion. The 500-m resolution simulation manages to reproduce convective rolls at local scale, which concentrate most of the aerosol particles and can locally affect the pollutant dispersion and air quality.

Sign in / Sign up

Export Citation Format

Share Document