dc.contributor.author | Johnson, BT | |
dc.contributor.author | Haywood, JM | |
dc.contributor.author | Langridge, JM | |
dc.contributor.author | Darbyshire, E | |
dc.contributor.author | Morgan, WT | |
dc.contributor.author | Szpek, K | |
dc.contributor.author | Brooke, JK | |
dc.contributor.author | Marenco, F | |
dc.contributor.author | Coe, H | |
dc.contributor.author | Artaxo, P | |
dc.contributor.author | Longo, KM | |
dc.contributor.author | Mulcahy, JP | |
dc.contributor.author | Mann, GW | |
dc.contributor.author | Dalvi, M | |
dc.contributor.author | Bellouin, N | |
dc.date.accessioned | 2017-02-27T15:34:37Z | |
dc.date.issued | 2016-11-24 | |
dc.description.abstract | We present observations of biomass burning
aerosol from the South American Biomass Burning Analysis
(SAMBBA) and other measurement campaigns, and
use these to evaluate the representation of biomass burning
aerosol properties and processes in a state-of-the-art
climate model. The evaluation includes detailed comparisons
with aircraft and ground data, along with remote sensing
observations from MODIS and AERONET. We demonstrate
several improvements to aerosol properties following
the implementation of the Global Model for Aerosol
Processes (GLOMAP-mode) modal aerosol scheme in the
HadGEM3 climate model. This predicts the particle size
distribution, composition, and optical properties, giving increased
accuracy in the representation of aerosol properties
and physical–chemical processes over the Coupled Largescale
Aerosol Scheme for Simulations in Climate Models
(CLASSIC) bulk aerosol scheme previously used in
HadGEM2. Although both models give similar regional distributions
of carbonaceous aerosol mass and aerosol optical
depth (AOD), GLOMAP-mode is better able to capture
the observed size distribution, single scattering albedo, and
Ångström exponent across different tropical biomass burning
source regions. Both aerosol schemes overestimate the
uptake of water compared to recent observations, CLASSIC
more so than GLOMAP-mode, leading to a likely overestimation
of aerosol scattering, AOD, and single scattering
albedo at high relative humidity. Observed aerosol vertical
distributions were well captured when biomass burning
aerosol emissions were injected uniformly from the surface
to 3 km. Finally, good agreement between observed and modelled
AOD was gained only after scaling up GFED3 emissions
by a factor of 1.6 for CLASSIC and 2.0 for GLOMAPmode.
We attribute this difference in scaling factor mainly
to different assumptions for the water uptake and growth of
aerosol mass during ageing via oxidation and condensation
of organics. We also note that similar agreement with observed
AOD could have been achieved with lower scaling
factors if the ratio of organic carbon to primary organic matter
was increased in the models toward the upper range of
observed values. Improved knowledge from measurements is
required to reduce uncertainties in emission ratios for black
carbon and organic carbon, and the ratio of organic carbon to
primary organic matter for primary emissions from biomass
burning. | en_GB |
dc.description.sponsorship | The Facility for Airborne Atmospheric
Measurement (FAAM) BAe-146 Atmospheric Research Aircraft is
jointly funded by the Met Office and Natural Environment Research
Council and operated by DirectFlight Ltd. We would like to thank
the dedicated efforts of FAAM, DirectFlight, INPE, the University
of São Paulo, and the Brazilian Ministry of Science and Technology
in making the SAMBBA measurement campaign possible. For
AERONET data we thank the PI investigators and their staff for
establishing and maintaining the sites used in this investigation
(Alta Floresta and Mongu: Brent Holben, Ilorin: Rachel T. Pinker,
Chiang Mai: Serm Janjai, Bonanza Creek: John R. Van de Castle,
Jabiru: Ross Mitchell). We thank Andrew Sayer and Robert Levy
from Goddard Space Flight Centre for their advice with MODIS
aerosol products. We thank Ville Vakkari for help in selecting data
from the Welgegund station. James Haywood, Eoghan Darybshire,
William Morgan, Hugh Coe, Graham Mann, and Nicolas
Bellouin were funded by SAMBBA (NERC grant NE/J009822/1).
Ben Johnson, James Haywood and Jane Mulcahy were funded
under the Joint UK BEIS/DEFRA – Met Office Hadley Centre
Climate Programme (GA01101). James Haywood was part funded
by the IMPALA grant (NE/M017214/1) via Future Climates for
Africa (FCA) funding provided by NERC and DFID | en_GB |
dc.identifier.citation | Vol. 16, pp. 14657 - 14685 | en_GB |
dc.identifier.doi | 10.5194/acp-16-14657-2016 | |
dc.identifier.uri | http://hdl.handle.net/10871/26091 | |
dc.language.iso | en | en_GB |
dc.publisher | European Geosciences Union | en_GB |
dc.rights | © Author(s) 2016. CC Attribution 3.0 License | en_GB |
dc.title | Evaluation of biomass burning aerosols in the HadGEM3 climate model with observations from the SAMBBA field campaign | en_GB |
dc.type | Article | en_GB |
dc.date.available | 2017-02-27T15:34:37Z | |
dc.identifier.issn | 1680-7316 | |
dc.description | This is the final version of the article. Available from the publisher via the DOI in this record. | en_GB |
dc.description | Published by Copernicus Publications on behalf of the European Geosciences Union. | en_GB |
dc.identifier.journal | Atmospheric Chemistry and Physics | en_GB |