2011 - Cooperative Institute for Research in Environmental Sciences ...

RP-04 Intercontinental Transport
and Chemical Transformation
n CSD-05 Tropospheric and Statospheric Transport and
Chemical Transformation
CSD-05TroposphericandStratosphericTransport
andChemicalTransformation
FEDERAL LEADS: TOM RYERSON AND STEVEN BROWN
CIRES LEAD: CHRISTINE ENNIS
NOAA Goals 2 and 3: Climate and Weather and Water
Project Goal: Carry out modeling studies and airborne and
surface measurements of chemical species to elucidate processes
involved in the intercontinental transport of photochemical
pollution.
Milestone 1. Analyze the long-range transport of aerosols
in the Arctic by using data from aircraft flights and
other sources to provide chemical characterization of the
aerosols. Impact: Aerosol particles, especially black carbon,
have large climate effects in the Arctic. This CIRES
research will analyze aerosols in the Arctic free troposphere,
polluted Arctic regions, biomass burning plumes
in the Arctic, and the air just above the pack ice, all of
which are potentially subject to long-range transport.
Aerosol data obtained in spring 2008 in the Arctic
The satellite image (top) shows Russian fires that were the source of dense
biomass burning plumes observed in the Arctic Atmosphere by (bottom
photo) CIRES investigators aboard the NOAA P-3.
130 CIRES Annual Report 2011
surface layer as well as in the free troposphere have been
analyzed for their chemical composition characteristics
in order to understand sources of aerosols reaching the
Arctic air, their fate and the impact they have on cloud
formation. By combining in-situ measurements of gas
and aerosol phase species with a long-range-transport
model, we determined that biomass burning (BB) activities
in southern Russia and southeastern Siberia contributed
significantly to springtime Arctic aerosol properties.
In addition to the BB plumes, plumes with characteristics
of fossil fuel combustion were observed in the free
troposphere. These plumes aloft were superimposed on a
polluted background of aged European wintertime emissions,
in contrast to the cleaner air at lower altitudes as
seen by Arctic surface measurement stations. The longrange
transport of pollutants across the continents resulted
in enhanced loadings of aged organic species in the
aerosol phase. Cloud condensation nuclei measurements
along with aerosol chemistry data indicate that, regardless
of the sources, most of the aerosols observed in the
Arctic activated at super saturations greater than 0.1% to
form clouds. The enhanced aerosol concentrations from
BB plumes suppressed ice formation within mixed phase
clouds. Black carbon mass was enhanced in biomass
burning plumes by up to a factor of five compared to the
background air. Black carbon was depleted in the Arctic
surface layer, and the depletion was anti-correlated with
ozone, indicating surface deposition as the mechanism
for the depletion.
RP-05 Aerosol Chemistry
and Climate Implications
n CSD-09 Aerosol Formation, Chemical Composition and
Radiative Properties
CSD-09AerosolFormation,ChemicalComposition
andRadiativeProperties
FEDERAL LEADS: DAN MURPHY, RU-SHAN GAO, DAVID FAHEY
AND GRAHAM FEINGOLD
CIRES LEAD: CHRISTINE ENNIS
NOAA Goals 2 and 3: Climate and Weather and Water
Project Goal: Carry out airborne, ship-based and groundbased
experiments that characterize the chemical composition
of radiatively important aerosols in the upper troposphere
and at Earth’s surface.
Milestone 1. Use data from the Hiaper Pole-to-Pole Observations
(HIPPO) mission deployments to examine the
mixing state and optical size of individual black-carbon
particles as well as black carbon mass loadings in remote
regions. Impact: Black carbon is an important component
of anthropogenic climate forcing in the Arctic region.
These measurements will provide a basis to evaluate the
treatment of black carbon in global aerosol models and
to characterize the contribution of black carbon to global
radiative forcing.