Results 61 to 70 of about 471 (203)

A statistical subgrid scale model for large eddy simulations

AIP Conference Proceedings, 2013
Cinlar velocity is a promising subgrid velocity model for large eddy simulation. The energy spectrum plays a central role for modeling the subgrid stress term in filtered Navier-Stokes equations. Considering a truncated Gamma distribution for radius of eddies, the subgrid scale energy spectrum has been computed analytically. In this study, we develop a
Kara, Rukiye, Caglar, Mine
openaire   +3 more sources

The evaluation of boundary‐layer turbulence in high‐resolution numerical weather prediction simulations using Doppler lidar

Quarterly Journal of the Royal Meteorological Society, EarlyView.
A new method compares both kilometer and sub‐kilometre weather model simulations with Doppler lidar observations to assess the representation of boundary‐layer turbulence. While bulk boundary‐layer properties are well represented, vertical velocity variance is strongly underestimated in both simulations.
Natalie J. Harvey, Helen F. Dacre, Kirsty E. Hanley, Humphrey W. Lean, Christopher J. Walden, Michael Baidu, Steven Boeing, Andrew N. Ross   +7 more
wiley   +1 more source

Eddy-topography interactions drive ocean ventilation across the Eocene–Oligocene transition: insights from a hierarchy of ocean model simulations

Environmental Research Communications
The Eocene–Oligocene transition (EOT), approximately 34 million years ago, represents one of the most profound climate shifts in Earth’s history—a rapid cooling that marked the transition from the warm Eocene greenhouse to the Cenozoic icehouse.
A Klocker, P E Isachsen, D R Munday, I Sauermilch, J M Whittaker   +4 more
doaj   +1 more source

Finite-volume models with implicit subgrid-scale parameterization for the differentially heated rotating annulus

Meteorologische Zeitschrift, 2015
The differentially heated rotating annulus is a classical experiment for the investigation of baroclinic flows and can be regarded as a strongly simplified laboratory model of the atmosphere in mid-latitudes.
Sebastian Borchert, Ulrich Achatz, Sebastian Remmler, Stefan Hickel, Uwe Harlander, Miklos Vincze, Kiril D. Alexandrov, Felix Rieper, Tobias Heppelmann, Stamen I. Dolaptchiev   +9 more
doaj   +1 more source

Scaling turbulence drives the general circulation

Quarterly Journal of the Royal Meteorological Society, EarlyView.
The NOAA Gulfstream SP4, which deployed the GPS dropsondes over the NE Pacific Ocean as part of the Winter Storms Project during the January–March periods of 2004, 2005 and 2006. Abstract Statistical multifractal analysis of airborne and dropsonde observations is used to show that persistence of velocity after molecular collisions breaks the continuous
Adrian F. Tuck
wiley   +1 more source

A stochastic extension of the explicit algebraic subgrid-scale models

Physics of Fluids, 2014
The explicit algebraic subgrid-scale (SGS) stress model (EASM) of Marstorp et al. [“Explicit algebraic subgrid stress models with application to rotating channel flow,” J. Fluid Mech. 639, 403–432 (2009)] and explicit algebraic SGS scalar flux model (EASFM) of Rasam et al.
Rasam, Amin, Brethouwer, Geert, Johansson, Arne   +2 more
openaire   +3 more sources

EnKF and expectation‐maximization based parameter estimation of a convective gravity‐wave parameterization using Strateole 2 constant‐level balloon data

Quarterly Journal of the Royal Meteorological Society, EarlyView.
An offline methodology is applied to estimate parameters of a convective gravity‐wave scheme using momentum flux (MF) observations from constant‐level balloons (left panels: pdfs of east and west MFs in green from observations and black from EnKF). The approach integrates an ensemble Kalman filter with an expectation‐maximization algorithm and permits ...
F. Lott, P. Tandeo, M. Pulido, D. Bardet
wiley   +1 more source

Increasing urban flash flood risk attributable to both climate and development

Quarterly Journal of the Royal Meteorological Society, EarlyView.
A new event impact attribution methodology that combines convection‐permitting climate model data with flood inundation modelling was used for a five‐hour flash‐flooding event in the suburbs of Leeds in 2014. The results show increased urban flood extent due to both climate change (+16%) and increased urbanisation (+29%).
Daniel F. Cotterill, Dann Mitchell, Peter A. Stott, Paul Bates, Youtong Rong, Leanne Archer   +5 more
wiley   +1 more source

Modulation of turbulence and mesoscale structure in nested large‐eddy simulations with a gray‐zone parent domain

Quarterly Journal of the Royal Meteorological Society, EarlyView.
The cell perturbation (CP) method mitigate mesoscale structural perturbations entering large‐eddy simulations (LES) from gray‐zone parent domains. The turbulent kinetic energy (TKE) bias‐filtering effect of CP increases with nesting ratio and is most pronounced under weakly convective conditions.
Jung‐Hee Ryu, Song‐Lak Kang
wiley   +1 more source

Modelling transport and deposition of caesium and iodine from the Chernobyl accident using the DREAM model [PDF]

Atmospheric Chemistry and Physics, 2002
A tracer model, DREAM (the Danish Rimpuff and Eulerian Accidental release Model), has been developed for modelling transport, dispersion and deposition (wet and dry) of radioactive material from accidental releases, as the Chernobyl accident. The model
J. Brandt, J. H. Christensen, L. M. Frohn   +2 more
doaj