1. An introduction to Terra-Incognita

4. A potpourri of LES with complex boundaries

3. Large-eddy simulation (LES)

A LARGE EDDY SIMULATION PERSPECTIVE OF TERRA-INCOGNITA

2. Rough wall SGS dynamics and Terra-Incognita

Kaimal & Finnigan (1994)

Increasing stratification z/L

is the characteristic length scale of the vertical velocity spectrum

convective stable

convective stable

Mes

o lim

itLE

S li

mit

A LOOK AT FILTERING

SIMPLE (CHEAP) FILTERING EXAMPLE …

Data in the atmospheric surface layer

MOVING BETWEEN MESO LIMIT AND LES LIMIT

MOVING BETWEEN MESO LIMIT AND LES LIMIT

MOVING BETWEEN MESO LIMIT AND LES LIMIT

MOVING BETWEEN MESO LIMIT AND LES LIMIT

MESO limit

MOVING BETWEEN MESO LIMIT AND LES LIMIT

Can we use targeted observations to provide insight as to the nature of SGS motions in high Re PBLs, and the Terra-Incognita regime?

HATS CONFIGURATIONS

Wide

Narrow

U

``2D plane of turbulence”

AN EXAMPLE OF LATERAL (Y) FILTERING

U

AN EXAMPLE OF LATERAL (Y) FILTERING

U

AN EXAMPLE OF LATERAL (Y) FILTERING

WHAT DO SGS STATISTICS FROM OBSERVATIONS LOOK LIKE?

Isotropic

HATS ARRAYS

OHATS FIELD CAMPAIGN

ASIT

Laser altimeters

18 CSATS

275 hours ``12 days of data” analyzed

OHATS

HATS

Meso Limit! What produces and ?

WHAT ARE THE FLUX EQUATIONS?

SGS scalar flux

0

Isotropic production

Anisotropic productionPressure destruction

0 0

00

Eddy viscosity model

Rotta model

Time scale

Eddy viscosity model

C=0.3 (Hatlee & Wyngaard, 2006)

Anisotropic model

SGS MOMENTUM FLUXES

Considerable Algebra !

Isotropic production

Anisotropic deviatoric productionPressure destruction

Rotta model

Time scale

0

0

00

OHATS

HATS

MESO Limit LES Limit

Measure of scale separation

OHATS

HATS

MESO Limit LES Limit

Measure of scale separation