Satellite-based evaluation of AeroCom model bias in biomass burning regions

Zhong, Qirui; Schutgens, Nick; van der Werf, Guido; van Noije, Twan; Bian, Huisheng

Satellite-based evaluation of AeroCom model bias in biomass burning regions

dc.contributor.author	Zhong, Qirui
dc.contributor.author	Schutgens, Nick
dc.contributor.author	van der Werf, Guido
dc.contributor.author	van Noije, Twan
dc.contributor.author	Bian, Huisheng
dc.date.accessioned	2022-04-04T14:36:06Z
dc.date.available	2022-04-04T14:36:06Z
dc.date.issued	2022-02-28
dc.description	Authors: Qirui Zhong, Nick Schutgens, Guido van der Werf, Twan van Noije, Kostas Tsigaridis,, Susanne E. Bauer,, Tero Mielonen, Alf Kirkevåg, Øyvind Seland, Harri Kokkola, Ramiro Checa-Garcia, David Neubauer, Zak Kipling, Hitoshi Matsui, Paul Ginoux, Toshihiko Takemura, Philippe Le Sager, Samuel Rémy, Huisheng Bian,, Mian Chin, Kai Zhang, Jialei Zhu, Svetlana G. Tsyro, Gabriele Curci,, Anna Protonotariou, Ben Johnson, Joyce E. Penner, Nicolas Bellouin, Ragnhild B. Skeie, and Gunnar Myhre	en_US
dc.description.abstract	Global models are widely used to simulate biomass burning aerosols (BBA). Exhaustive evaluations on model representation of aerosol distributions and properties are fundamental to assess health and climate impacts of BBA. Here we conducted a comprehensive comparison of Aerosol Comparisons between Observation project (AeroCom) model simulations with satellite observations. A total of 59 runs by 18 models from three AeroCom Phase III experiments (i.e., Biomass Burning Emissions, CTRL16, and CTRL19) and 14 satellite products of aerosols were used in the study. Aerosol optical depth (AOD) at 550 nm was investigated during the fire season over three key fire regions reflecting different fire dynamics (i.e., deforestation-dominated Amazon, Southern Hemisphere Africa where savannas are the key source of emissions, and boreal forest burning on boreal North America). The 14 satellite products were first evaluated against AErosol RObotic NETwork (AERONET) observations, with large uncertainties found. But these uncertainties had small impacts on the model evaluation that was dominated by modeling bias. Through a comparison with Polarization and Directionality of the Earth’s Reflectances (POLDER-GRASP) observations, we found that the modeled AOD values were biased by -93–152 %, with most models showing significant underestimations even for the state-of-art aerosol modeling techniques (i.e., CTRL19). By scaling up BBA emissions, the negative biases in modeled AOD were significantly mitigated, although it yielded only negligible improvements in the correlation between models and observations, and the spatial and temporal variations of AOD biases did not change much. For models in CTRL16 and CTRL19, the large diversity in modeled AOD was in almost equal measures caused by diversity in emissions, lifetime, and mass extinction coefficient (MEC). We found that in the AEROCOM ensemble, BBA lifetime correlated significantly with particle deposition (as expected) and in turn correlated strongly with precipitation. Additional analysis based on Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP) aerosol profiles suggested that the altitude of the aerosol layer in the current models was generally too low, which also contributed to the bias in modeled lifetime. Modeled MECs exhibited significant correlations with the Ångström Exponent (AE, an indicator of particle size). Comparisons with the POLDER-GRASP observed AE suggested that the models tended to overestimate AE (underestimated particle size), indicating a possible underestimation of MECs in models. The hygroscopic growth in most models generally agreed with observations and might not explain the overall underestimation of modeled AOD. Our results imply that current global models comprise biases in important aerosol processes for BBA (e.g., emissions, removal, and optical properties) that remain to be addressed in future research.	en_US
dc.description.sponsorship	This work was financially supported by Netherlands Organization for Scientific Research (NWO; ALWGO.2018.052). K.T. and S.E.B. acknowledge NASA MAP for support. Resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Center for Climate Simulation (NCCS) at Goddard Space Flight Center. H.M. was supported by the Ministry of Education, Culture, Sports, Science and Technology of Japan and the Japan Society for the Promotion of Science (MEXT/JSPS) KAKENHI Grant Numbers JP19H04253, JP19H05699, JP19KK0265, JP20H00196, and JP20H00638, MEXT Arctic Challenge for Sustainability phase II (ArCS-II; JPMXD1420318865) project, and the Environment Research and Technology Development Fund 2–2003 (JPMEERF20202003) of the Environmental Restoration and Conservation Agency. We thank all the modelers that have submitted AeroCom model data used in this work.	en_US
dc.description.uri	https://acp.copernicus.org/preprints/acp-2022-96/	en_US
dc.format.extent	47 pages	en_US
dc.genre	journal articles	en_US
dc.genre	preprints	en_US
dc.identifier	doi:10.13016/m2knli-1oip
dc.identifier.uri	https://doi.org/10.5194/acp-2022-96
dc.identifier.uri	http://hdl.handle.net/11603/24512
dc.language.iso	en_US	en_US
dc.publisher	EGU	en_US
dc.relation.isAvailableAt	The University of Maryland, Baltimore County (UMBC)
dc.relation.ispartof	UMBC Joint Center for Earth Systems Technology
dc.relation.ispartof	UMBC Faculty Collection
dc.rights	This work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law.	en_US
dc.rights	Public Domain Mark 1.0	*
dc.rights.uri	http://creativecommons.org/publicdomain/mark/1.0/	*
dc.title	Satellite-based evaluation of AeroCom model bias in biomass burning regions	en_US
dc.type	Text	en_US