The Technical Note series provides an outlet for a variety of NCAR manuscripts that contribute in specialized ways to the body of scientific knowledge but which are not suitable for journal, monograph, or book publication. Reports in this series are issued by the NCAR Scientific Divisions ; copies may be obtained on request from the Publications Office of NCAR. Designation symbols for the series include: Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the authors and do not necessarily reflect the views of the National Science Foundation.

/pdf/a-description-of-the-advanced-research-wrf-version-3-o5qjsdx46x.pdf

A Description of the Advanced Research WRF Version 3

The ERA5 global reanalysis

http://people.atmos.ucla.edu/alex/ROMS/ROMSArticle2005.pdf

The regional oceanic modeling system (ROMS): a split-explicit, free-surface, topography-following-coordinate oceanic model

A Description of the Fifth-Generation Penn State/ NCAR Mesoscale Model (MM5), NCAR/TN-398+STR

/pdf/a-description-of-the-fifth-generation-penn-state-ncar-4380gcr9if.pdf

A description of the fifth-generation Penn State/NCAR Mesoscale Model (MM5)

https://coaps.fsu.edu/pub/eric/OCP5930/Papers/MPDATAfirst.JCP054.pdf

A Fully Multidimensional Positive Definite Advection Transport Algorithm with Small Implicit Diffusion

The development of negative values for positive definite scalars in the solution of the advection equation is an important difficulty in numerical modeling. This paper proposes a new positively definite advection scheme which has a simple form, small implicit diffusion and low computational cost. Comparisons of the present scheme with some other known positive definite schemes are also presented.

A Simple Positive Definite Advection Scheme with Small Implicit Diffusion

We study the flow of a density-stratified fluid past a three-dimensional obstacle, using a numerical model. Our special concern is the response of the fluid when the Froude number is near or less than unity. Linear theory is inapplicable in this range of Froude number, and the present numerical solutions show the rich variety of phenomena that emerge in this essentially nonlinear flow regime. Two such phenomena, which occupy Parts I and II of this study, are the formation of a pair of vertically oriented vortices on the lee side and a zone of flow reversal on the windward side of the obstacle. The Ice vortices have been explained as a consequence of the separation of the viscous boundary layer from the obstacle however, this boundary layer is absent (by design) in the present experiments and lee vortices still occur. We argue that a vertical component of vorticity develops on the lee side owing to the tilting of horizontally oriented vorticity produced baroclinically as the isentropes deform in r...

Low Froude Number Flow Past Three-Dimensional Obstacles. Part I: Baroclinically Generated Lee Vortices

https://coaps.fsu.edu/pub/eric/OCP5930/Papers/MPDATAreview.pdf

MPDATA: A Finite-Difference Solver for Geophysical Flows

Gravity waves play an important role in the redistribution of heat and moisture in a deep convecting cloud field. We explore this role in a two-dimensional numerical experiment on a simple moist convecting system consisting of an isolated long-lasting nonprecipitating cloud in a calm atmosphere with no surface forcing. The cloud develops a horizontally averaged density variation with height which is neutrally buoyant with respect to a moist adiabatic. The buoyancy difference between the cloud and the undisturbed sounding produces circulations that can be understood as spreading gravity waves which adjust the environmental buoyancy to be equal to the cloud buoyancy by compensating subsidence. Unlike the circulations inside clouds, this adjustment takes place without turbulent mixing. Hence, the “buoyancy adjustment time” T1 during which the environment comes into rough buoyant equilibrium with the clouds is much shorter than the “mixing time” T2 which it takes a tracer, initially concentrated at s...

Piotr K. Smolarkiewicz

Papers

A Fully Multidimensional Positive Definite Advection Transport Algorithm with Small Implicit Diffusion

A Simple Positive Definite Advection Scheme with Small Implicit Diffusion

Low Froude Number Flow Past Three-Dimensional Obstacles. Part I: Baroclinically Generated Lee Vortices

MPDATA: A Finite-Difference Solver for Geophysical Flows

Gravity Waves, Compensating Subsidence and Detrainment around Cumulus Clouds