Identification

Title

Vertical variations of mixing lengths under neutral and stable conditions during CASES99

Abstract

An investigation on vertical variations of the mixing lengths for momentum and heat under neutral and stable conditions was conduced using the data collected from the Cooperative Atmosphere-Surface Exchange Study in 1999 (CASES99). By comparing κz with the mixing lengths under neutral conditions calculated using the observations from CASES99, the vertical layer where Monin-Obukhov similarity theory (MOST) is was identified. Here κ is the von Kármán constant and z is the height above the ground. On average, MOST is approximately valid between 0.5 m and 10 m. Above the layer, the observed mixing lengths under neutral conditions are smaller than the MOST κz and can be approximately described by Blackadar's mixing length, κz/(1+ κz/l∞), with l∞ = 15 m for up to z ~ 20 m for the mixing length for momentum, and up to the highest observation height for the mixing length for heat. Above ~ 20 m, the mixing length for momentum approaches a constant. Both MOST κz and Blackadar's formula systematically overestimate the mixing length for momentum above ~ 20 m, leading to overestimates of turbulence.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.org/ark:/85065/d79887js

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

Geographic location

West bounding longitude

East bounding longitude

North bounding latitude

South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2011-10-01T00:00:00Z

Frequency of update

Quality and validity

Lineage

Conformity

Data format

name of format

version of format

Constraints related to access and use

Constraint set

Use constraints

Limitations on public access

None

Responsible organisations

Responsible party

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact