Identification

Title

Transport of carbon dioxide, water vapor, and ozone by turbulence and local circulations

Abstract

Nocturnal land breezes and daytime lake breezes are studied using data collected by the Canadian Twin Otter aircraft and a deck boat which traversed Candle Lake during the Boreal Ecosystem-Atmosphere Study (BOREAS). The nocturnal vertical transport of CO2, water vapor, and ozone over the lake consists of two parts: (1) mesoscale rising motion associated with land breeze convergence and (2) significant turbulence and vertical mixing driven by buoyancy in the lower part of the internal boundary layer and shear generation in the top part of the internal boundary layer. For comparison, the role of the lake in the daytime is examined in terms of formation of a stable internal boundary layer due to advection of warm air from land with small CO2 concentration over the cooler lake surface. Analysis of the aircraft and boat data indicates that the nocturnal land breeze plays an important role in the regional CO2 budget in the lake region. In the present study, CO2 is advected horizontally by a nocturnal land breeze circulation and vented vertically over Candle Lake (“chimney effect”). Such near-surface horizontal transport implies that part of the respirated CO2 never reaches the tower observational level, particularly under light wind conditions. This study speculates that preferred locations of vertical venting of CO2 may also occur due to convergence of nocturnal drainage circulations or flow meandering, although probably weaker than that associated with the land breeze. These circulations partly explain recent findings that tower-measured nocturnal turbulent fluxes of CO2 above the canopy and the subcanopy storage of CO2 frequently sum to less than the total respiration of CO2, leading to “missing CO2.” Unfortunately, the present study does not allow evaluation of all of the terms in the carbon dioxide budget.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d7q81cxf

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

1998-10-27T00:00:00Z

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