Origin and radiative forcing of black carbon transported...
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Monika Kopacz 1,* , Denise Mauzerall 1 , Jun Wang 2 , Eric Leibensperger 3 , Daven Henze 4 , Kumaresh Singh 5 Origin and radiative forcing of black carbon transported to the Himalayas and Tibetan Plateau: an adjoint analysis 1. Princeton U. *now at NOAA Climate Program Office, 2. U. Nebraska-Lincoln, 3. Harvard U., 4. U. Colorado-Boulder, 5. Virginia Tech. 5 th GEOS-Chem meeting, May 2, 2011 (Kopacz et al. ACP 2011)
Transcript of Origin and radiative forcing of black carbon transported...
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Monika Kopacz1,*, Denise Mauzerall1, Jun Wang2,
Eric Leibensperger3, Daven Henze4, Kumaresh Singh5
Origin and radiative forcing of black carbon
transported to the Himalayas
and Tibetan Plateau: an adjoint analysis
1. Princeton U. *now at NOAA Climate Program Office, 2. U. Nebraska-Lincoln, 3.
Harvard U., 4. U. Colorado-Boulder, 5. Virginia Tech.
5th GEOS-Chem meeting, May 2, 2011
(Kopacz et al. ACP 2011)
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Emissions contributions of BC to the Himalayas
Identify origin and magnitude of emissions of BC
that reaches the glaciers. Use adjoint GEOS-Chem (v8) to identify emission contributions
from source regions to concentrations at receptor (air column); i.e.
where did BC emissions come from?
Focus on Asian glaciers: 5 sites on Himalayas and Tibetan
Plateau, under influence of various air
masses, and where we have ice core
data.
Glaciers and rivers in Himalayas and Tibetan
Plateau
")")
")")
")
Compute radiative forcing due to
BC:Consider direct and snow-albedo effects;
BC simulated by GEOS-Chem global CTM
Receptor
location
choices
W/m2
Origin of
BC
reaching
glacier
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BC emissions and concentrations
Annual average BC emissions from all sources
Cooke et al. (1999), Bond et al. (2004)
Annual average BC surface concentrations
1010.10.010.001
μg/m34e63e52e41e3 1e96e7
Simulated by GEOS-Chem modelμg/m2/s
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Site Model: BC
in snow
(ng/g)
Observations:
BC in snow
(ng/g)
1. Mt. Everest 22.1 43.1
2. Zuoqiupu 13.3/44.7 7.3/15.9
3. Meikuang 28.0 446
4. Mt. Muztagh 19.6 37.2
5. Miao’ergou 94.5 111
BC in snow at 5 receptors: model
evaluation
Conclusions:
• model is able to reproduce
seasonal cycle (monsoon
concentrations < non-
monsoon concentrations)
• no consistent bias: a mix of
underestimate and
overestimate
• lower concentrations in the
Himalayas than in Tibetan
Plateau
Data: BC concentrations in snow and precipitation
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BC in snow at 5 receptors:
radiative forcingRadiative transfer model from Wang et
al. (2008)
530
995
760
hPa
Which
emissions
contribute to
this radiative
forcing?
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Origin of BC Emissions reaching Mt. Everest
Results:
• Striking seasonal
and spatial
variation of
emissions
• 90% of BC in this
gridbox (~ 40
tons/day) comes
from India, China
and Nepal
• January biomass
burning in tropical
Africa and April
emissions from
Middle East make a
significant
contribution (~ 1
ton/day)
Average BC emission contributions to the grid box
containing Mt. Everest.
μg/km2/day
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Origin of BC Emissions reaching SE Tibetan Plateau*
*Here, BC deposition increased by a factor of 3.5 from 1998 to 2005 (Xu et al. 2009)
Results:
• Striking seasonal
and spatial
variation of
emissions
• India, China and
Nepal emit majority
of BC found at
Zuoqiupu (~11
tons/day)
• Emissions from
C. China make a
large contribution
during monsoon
and post-monsoon
seasons.
Average BC emissions arriving in the grid box containing
Zuoqiupu glacier.
μg/km2/day
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μg/km2/day
Origin of BC Emissions reaching NE Tibetan Plateau*
Results:
• Striking seasonal
and spatial
variation of
emissions
• W. and C. China
emit majority of BC
that arrives at
Meikuang, ~8
tons/day (via local
and long-range
transport)
• Middle Eastern
(Iranian) emissions
make a substantial
seasonal
contribution (~1
ton/day in April)
Average BC emissions arriving in the grid box containing
Meikuang glacier.
*Near the start of several major rivers.
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Origin of BC Emissions reaching W Tibetan Plateau
μg/km2/day
Average BC emissions arriving in the grid box containing
Mt. Muztagh glacier.Results:• Striking seasonal
and spatial variation
of emissions
• W. China and
Pakistan emit
majority of BC
reaching Mt.
Muztagh (1-13
tons/day)
• Emissions from
Middle East (0.5-3
tons/day) and India
(0.2 - 2.7) make
smaller, but
substantial seasonal
contribution
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Conclusions
Source attribution using GEOS-Chem adjoint is a uniquely informative quantitative analysis of BC in the Asian glaciers.
Striking variety of emission locations contribute to BC concentrations and deposition onto Asian glaciers. Exact glacier location and season influence contribution.
Substantial positive radiative forcing in Asian glaciers is due to snow-albedo effect, especially during summer months.
BC emissions from Western and Central China, India, Nepal and Middle East all reach Asian glaciers in substantial amounts.
Uncertainties: model emissions, transport, precipitation, assumptions on snow properties and BC indirect effect.
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Emission inventory database: new
community effort
GEIAGlobal Emissions Inventory Activity
http://www.geiacenter.org/http://ether.ipsl.jussieu.fr/
CIERACommunity Initiative for Emissions Research and Applications http://ciera-air.org/
Holistic community effort to improve emissions information
•Emissions collaboration space (with data sets and documentation)•Developed by and serving broad community•Dynamic data access•Online data analysis tools•Support: NOAA, EPA, ESIP•Nascent effort under active development
Contact person: Greg Frost at NOAA/ESRL/CSD
http://www.geiacenter.org/http://ether.ipsl.jussieu.fr/http://ciera-air.org/http://ciera-air.org/http://ciera-air.org/
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Monika Kopacz ([email protected])
Thank you!
Acknowledgements: NOAA/GFDL computing resources,
Princeton STEP postdoctoral fellowship
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Emission contributions to the North of Tibetan
Plateau
ug/km2/day
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Total BC emissions across seasons
No seasonality, except for biomass burning
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BC surface concentrations
1010.10.010.001 μg/m3
January April
July October
