This paper discusses aircraft observations and large-eddy simulation (LES) modeling of 15 May 2008, North Sea boundary-layer clouds from the EUCAARIIMPACT field campaign. These clouds are advected from the northeast by the prevailing lower-tropospheric winds and featured stratocumulus-over-cumulus cloud formations. An almost-solid stratocumulus deck in the upper part of the relatively deep, wea...

The purpose of these lectures is to present elements of the equations and algorithms used in numerical models of the large-scale ocean circulation. Such models generally integrate the ocean’s primitive equations, which are based on Newton’s Laws applied to a continuum fluid under hydrostatic balance in a spherical geometry, along with linear irreversible thermodynamics and subgrid scale (SGS) p...

By PETRI RÄISÄNEN , HOWARD W. BARKER , MARAT F. KHAIROUTDINOV , JIANGNAN LI and DAVID A. RANDALL Department of Physics and Atmospheric Science, Dalhousie University, Canada Cloud Physics Research Division, Meteorological Service of Canada, Canada Department of Atmospheric Science, Colorado State University, United States Climate Modelling and Analysis Division, Meteorological Service of Canada,...

(Received 00 Month 200x; In final form 00 Month 200x) We study the dynamics of thermonuclear flames propagating in fuel stirred by stochastic forcing. The fuel consists of carbon and oxygen in a state which is encountered in white dwarfs close to the Chandrasekhar limit. The level set method is applied to represent the flame fronts numerically. The computational domain for the numerical simulat...

We present a new approach for the construction of stochastic subgrid scale parameterizations. Starting from a high-resolution finite-difference discretization of some model equations, the new approach is based on splitting the model variables into fast, small-scale and slow, large-scale modes by averaging the model discretization over neighboring grid cells. After that, the fast modes are elimi...

LES models for subgrid scalar transport and dissipation are assessed through joint experimental and numerical studies using experimental data from an axisymmetric, turbulent, co-flowing jet, and large eddy simulation of scalar mixing in a round turbulent jet. The dissipation models tested include: a gradient-based model, which is based on a local equilibrium assumption, a model that assumes pro...

Regional Climate Models RCMs are practical downscaling tools to yield regional climate information for assessing the impacts of climate variability and change The Paci c Northwest National Labora tory PNNL RCM based on the Penn State NCAR Mesoscale Model MM features a novel subgrid treatment of orographic precipitation for coupling climate hydrologic and ecologic processes at the watershed scal...