Identification

Title

Patterns of COâ‚‚ and radiocarbon across high northern latitudes during International Polar Year 2008

Abstract

High-resolution in situ COâ‚‚ measurements were conducted aboard the NASA DC-8 aircraft during the ARCTAS/POLARCAT field campaign, a component of the wider 2007â€“2008 International Polar Year activities. Data were recorded during large-scale surveys spanning the North American sub-Arctic to the North Pole from 0.04 to 12 km altitude in spring and summer of 2008. Influences on the observed COâ‚‚ concentrations were investigated using coincident CO, black carbon, CHâ‚ƒCN, HCN, Oâ‚ƒ, C2Cl4, and Î”Â¹ â´COâ‚‚ data, and the FLEXPART model. In spring, the COâ‚‚ spatial distribution from 55Â°N to 90Â°N was largely determined by the long-range transport of air masses laden with Asian anthropogenic pollution intermingled with Eurasian fire emissions evidenced by the greater variability in the mid-to-upper troposphere. At the receptor site, the enhancement ratios of COâ‚‚ to CO in pollution plumes ranged from 27 to 80 ppmv ppmv-1 with the highest anthropogenic content registered in plumes sampled poleward of 80Â°N. In summer, the COâ‚‚ signal largely reflected emissions from lightning-ignited wildfires within the boreal forests of northern Saskatchewan juxtaposed with uptake by the terrestrial biosphere. Measurements within fresh fire plumes yielded COâ‚‚ to CO emission ratios of 4 to 16 ppmv ppmv-1 and a mean COâ‚‚ emission factor of 1698 Â± 280 g kg-1 dry matter. From the Â¹ â´C in COâ‚‚ content of 48 whole air samples, mean spring (46.6 Â± 4.4â€°) and summer (51.5 Â± 5â€°) Î”Â¹ â´COâ‚‚ values indicate a 5â€° seasonal difference. Although the northern midlatitudes were identified as the emissions source regions for the majority of the spring samples, depleted Î”Â¹ â´COâ‚‚ values were observed in <1% of the data set. Rather, ARCTAS Î”Â¹ â´COâ‚‚ observations (54%) revealed predominately a pattern of positive disequilibrium (1-7â€°) with respect to background regardless of season owing to both heterotrophic respiration and fire-induced combustion of biomass. Anomalously enriched Î”Â¹ â´COâ‚‚ values (101-262â€°) measured in emissions from Lake Athabasca and Eurasian fires speak to biomass burning as an increasingly important contributor to the mass excess in Î”Â¹ â´COâ‚‚ observations in a warming Arctic, representing an additional source of uncertainty in the quantification of fossil fuel COâ‚‚.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.org/ark:/85065/d7mw2hn5

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

2011-07-16T00:00:00Z

Frequency of update

Quality and validity

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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