Identification

Title

Evaluating a new deposition velocity module in the Noah land surface model

Abstract

The community Noah land-surface model (Noah LSM) has been modified to couple with a photosynthesis-transpiration scheme (GEM) to estimate the deposition velocity (V d) for air quality studies. This new capability of the Noah-GEM model was tested in a point version of the National Center for Atmospheric Research-High Resolution Land Data Assimilation System (HRLDAS). Ozone V d observations from June 1–30, 2002 over the AmeriFlux forested site located at Niwot Ridge, Colorado, USA (40°1'58"N;105°32'47"W) were used. The model reasonably captures V d variations for both dry and wet conditions but has problems at nighttime. Experiments were performed to assess the sensitivity of V d calculations to surface characteristics related to vegetation and soil parameters. The results indicated that V d values are sensitive to accurate specifications of the leaf area index (LAI) and a lesser extent to vegetation type, maximum stomatal resistance (R smax) and soil texture prescription. The model sensitivity to canopy resistance was noted for both daytime and nighttime. For this forest site, neither soil textures nor soil moisture appeared to affect V d calculations significantly, though they affected the surface heat-flux estimation particularly under low soil moisture conditions. Therefore, the V d estimation in the Noah model can be enhanced by either site-specific LAI or assimilating regional normal difference vegetation index information for specific time periods. Results also highlighted the need to lower the current constant R smax value used in Noah and other land-surface models.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d78p61sh

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

2010-11-01T00:00:00Z

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