Identification

Title

Implementation and Evaluation of a Unified Turbulence Parameterization Throughout the Canopy and Roughness Sublayer in Noah-MP Snow Simulations

Abstract

The Noah-MP land surface model (LSM) relies on the Monin-Obukhov (M-O) Similarity Theory (MOST) to calculate land-atmosphere exchanges of water, energy, and momentum fluxes. However, MOST flux-profile relationships neglect canopy-induced turbulence in the roughness sublayer (RSL) and parameterize within-canopy turbulence in an ad hoc manner. We implement a new physics scheme (M-O-RSL) into Noah-MP that explicitly parameterizes turbulence in RSL. We compare Noah-MP simulations employing the M-O-RSL scheme (M-O-RSL simulations) and the default M-O scheme (M-O simulations) against observations obtained from 647 Snow Telemetry (SNOTEL) stations and two AmeriFlux stations in the western United States. M-O-RSL simulations of snow water equivalent (SWE) outperform M-O simulations over 64% and 69% of SNOTEL sites in terms of root-mean-square-error (RMSE) and correlation, respectively. The largest improvements in skill for M-O-RSL occur over closed shrubland sites, and the largest degradations in skill occur over deciduous broadleaf forest sites. Differences between M-O and M-O-RSL simulated snowpack are primarily attributable to differences in aerodynamic conductance for heat underneath the canopy top, which modulates sensible heat flux. Differences between M-O and M-O-RSL within-canopy and below-canopy sensible heat fluxes affect the amount of heat transported into snowpack and hence change snowmelt when temperatures are close to or above the melting point. The surface energy budget analysis over two AmeriFlux stations shows that differences between M-O and M-O-RSL simulations can be smaller than other model biases (e.g., surface albedo). We intend for the M-O-RSL physics scheme to improve performance and uncertainty estimates in weather and hydrological applications that rely on Noah-MP.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.org/ark:/85065/d7w95dnp

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

2021-11-18T00:00:00Z

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