Consulta: subjectFacets:"Boundary layers"
Registros recuperados: 3
Data/hora: 13/06/2024 21:59:15

Potential Vorticity diagnostics based on balances between volume integral and boundary conditions
Provedor de dados: 5
Autores: Morel, Yves; Gula, Jonathan; Ponte, Aurelien.
Taking advantage of alternative expressions for potential vorticity (PV) in divergence forms, we derive balances between volume integral of PV and boundary conditions, that are then applied to practical computations of PV: • we propose a new method for diagnosing the Ertel potential vorticity from model output, that preserves the balances; • we show how the expression of PV can be derived in general coordinate systems. This is here emphasised with isopycnic coordinates by generalising the PV expression to the general Navier-Stokes equations; • we propose a generalised derivation for the Haynes-McIntyre impermeability theorem, which highlights the role of the bottom boundary condition choice (e.g. no-slip vs free-slip) and mixing near the bottom boundary...
Tipo: Text
Palavras-chave: Potential vorticity; Boundary conditions; General circulation; Vortex; Fronts; Boundary layers.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00494/60525/63988.pdf

A case study of ship track formation in a polluted marine boundary layer
Provedor de dados: 27
Autores: Noone, K.J.; Johnson, D.W.; Taylor, J.P.; Ferek, R.J.; Garrett, T.; Hobbs, P.V.; Durkee, P.A.; Nielsen, K.; Öström, E.; O'Dowd, C.; Smith, M.H.; Russell, L.M.; Flagan, R.C.; Seinfeld, J.H.; De Bock, L.; Van Grieken, R.; Hudson, J.G.; Brooks, I.; Gasparovic, R.F.; Pockalny, R.A.
A case study of the effects of ship emissions on the microphysical, radiative, and chemical properties of polluted marine boundary layer clouds is presented. Two ship tracks are discussed in detail. &lt;i&gt;In situ&lt;/i&gt; measurements of cloud drop size distributions, liquid water content, and cloud radiative properties, as well as aerosol size distributions (outside-cloud, interstitial, and cloud droplet residual particles) and aerosol chemistry, are presented. These are related to remotely sensed measurements of cloud radiative properties. The authors examine the processes behind ship track formation in a polluted marine boundary layer as an example of the effects of anthropogenic particulate pollution on the albedo of marine stratiform clouds.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Aerosols; Air pollution; Albedo; Atmosphere; Atmosphere; Atmospheric boundary layer; Boundary layers; Cloud cover; Clouds; Man-induced effects; Marine environment; Marine pollution; Particulates; Remote sensing; Ships.
Ano: 2000
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=8839

Determination of methanesulfonic acid and non-sea-salt sulfate in single marine aerosol particles
Provedor de dados: 27
Autores: Kolaitis, L.N.; Bruynseels, F.; Van Grieken, R.; Andreae, M.O.
In open ocean waters the predominant volatile sulfur compound is dimethyl sulfide (DMS), representing almost 90% of the marine sulfur emissions. Methanesulfonic acid (MSA), one of the oxidation products of DMS, is consequently an important constituent of marine aerosols. Laser microprobe mass analysis (LAMMA) has been used for single-particle analysis of particles collected in the marine boundary layer. MSA, like the non-sea-salt sulfate, is mainly associated with the smallest aerosol particles, whose LAMMA spectra match the reference fingerprint spectra of MSA salts, sodium methanesulfonate and ammonium methanesulfonate. The presence of nitrate and heavy metal ions in the LAMMA spectra can reveal, to a certain extent, the degree of air pollution at the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Aerosols; Air pollution; Boundary layers; Heavy metals; Marine environment; Nitrates; Particle size; Sulphates.
Ano: 1989
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3177