Identification

Title

The impact of North American anthropogenic emissions and lightning on long-range transport of trace gases and their export from the continent during summers 2002 and 2004

Abstract

We analyze the contribution of North American (NA) lightning and anthropogenic emissions to ozone concentrations, radiative forcing, and export fluxes from North America during summers 2002 and 2004 using the University of Maryland Chemical Transport Model (UMD-CTM) driven by GEOS-4 reanalysis. Reduced power plant emissions (NOx SIP Call) and cooler temperatures in 2004 compared to 2002 resulted in lower ambient ozone concentrations over the eastern United States. Lightning flash rates in early summer 2004 were 50% higher than 2002 over the United States. Over the North Atlantic, changes in ozone column between early summer 2002 and 2004 due to changes in lightning and meteorology exceeded the change due to emission reductions by a factor of 7. Late summer changes in lightning had a much smaller impact on ozone columns. In summer 2004, net downward radiative flux at the tropopause due to ozone produced from anthropogenic emissions ranged from 0.15 to 0.30 W m⁻² across the North Atlantic, while that due to ozone produced from lightning NO emissions ranged from 0.20 to 0.50 W m⁻². Enhanced lofting of polluted air followed by stronger westerly winds led to more net export of NOx, NOy, and ozone in early summer 2004 than 2002 despite reduced anthropogenic emissions. Ozone export fluxes across the eastern NA boundary due to anthropogenic emissions were factors of 1.6 and 2 larger than those due to lightning in 2004 and 2002, respectively. Doubling the NA lightning NO source increased downwind ozone enhancements due to lightning NO emissions by one third.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d728086h

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

2011-04-07T00:00:00Z

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