@article {2949,
	title = {Contemporary sources dominate carbonaceous aerosol on the North Slope of Alaska},
	journal = {Science of The Total Environment},
	volume = {831},
	year = {2022},
	month = {Jan-07-2022},
	pages = {154641},
	abstract = {As the Arctic continues to change and warm rapidly, it is increasingly important to understand the organic carbon (OC) contribution to Arctic aerosol. Biogenic sources of primary and secondary OC in the Arctic will be impacted by climate change, including warming temperatures and earlier snow and ice melt. This study focuses on identifying potential sources and regional influences on the seasonal concentration of organic aerosol through analysis of chemical and isotopic composition. Aerosol samples were collected at two sites on the North Slope of Alaska (Utqiagvik, UQK, and Oliktok Point, OLK, which is in an Arctic oilfield) over three summers from 2015 to 2017. The elemental carbon (EC) trends at each site were used to understand local combustion influences. Local sources drove EC concentrations at Oliktok Point, where high EC was attributed to oil and gas extraction activity, including diesel combustion emissions. Utqiagvik had very low EC in the summer. OC was more similar in concentration and well correlated between the two sites with high contributions of contemporary carbon by radiocarbon apportionment (UQK = 74\%, OLK = 63\%), which could include both marine and terrestrial sources of contemporary carbon (e.g. primary and secondary biogenic, biomass burning and/or associated SOA, and bioaerosols). OC concentrations are strongly correlated to maximum ambient temperatures on the NSA during the summer, which may have implications for predicting future OC aerosol concentrations in a warming Arctic. Biomass burning was determined to be an episodic influence at both sites, based on interpretation of combined aerosol composition, air mass trajectories, and remote sensing of smoke plumes. The results from this study overall strongly suggests contribution from regional sources of contemporary organic aerosol on the NSA, but additional analysis is needed to better constrain contributions from both biogenic sources (terrestrial and/or marine) and bioaerosol to better understand temperature-related aerosol processes in the Arctic.},
	issn = {00489697},
	doi = {10.1016/j.scitotenv.2022.154641},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S004896972201734X},
	author = {Moffett, Claire E. and Mehra, Manisha and Barrett, Tate E. and Gunsch, Matthew J. and Pratt, Kerri A. and Sheesley, Rebecca J.}
}
@article {2465,
	title = {Carbon isotope-constrained seasonality of carbonaceous aerosol sources from an urban location (Kanpur) in the Indo-Gangetic Plain},
	journal = {Journal of Geophysical Research: Atmospheres},
	volume = {122},
	year = {2017},
	month = {Apr-05-2018},
	pages = {4903 - 4923},
	abstract = {The Indo-Gangetic Plain (IGP) in northern India, Pakistan and Bangladesh is a major source of carbonaceous aerosols in South Asia. However, poorly constrained seasonality of their sources over the IGP leads to large uncertainty in climate and health effects. Here, we present a first dataset for year-round radiocarbon (Δ14C) and stable carbon (δ13C) based source apportionment of total carbon (TC) in ambient PM10 (n = 17) collected from an urban site (Kanpur: 26.5 {\textdegree}N, 80.3 {\textdegree}E) in the IGP during January 2007-January 2008. The year-round 14C-based fraction biomass (fbio-TC) estimate at Kanpur averages ~77 {\textpm} 7\%, emphasize an impact of biomass burning emissions (BBEs). The highest fbio-TC(\%) is observed in fall season (October-November: 85 {\textpm} 6\%) followed by winter (December-February: 80 {\textpm} 4\%) and spring (March-May: 75 {\textpm} 8\%), while lowest values found in summer (June-September: 69 {\textpm} 2\%). Since biomass/coal combustion and vehicular emissions mostly contribute to carbonaceous aerosols over the IGP, we predict δ13CTC (δ13Cpred) over Kanpur using known δ13C source signatures and the measured Δ14C value of each sample. The seasonal variability of δ13Cobs - δ13Cpred versus Δ14CTC together with air mass back trajectories and MODIS fire count data reveal that carbonaceous aerosols in winter/fall are significantly influenced by atmospheric aging (downwind transport of crop-residue burning/wood combustion emissions in the northern IGP), while local sources (wheat residue combustion/vehicular emissions) dominate in spring/summer. Given the large temporal and seasonal variability in sources and emission strength of TC over the IGP, 14C-based constraints are, thus, crucial for reducing their uncertainties in carbonaceous aerosol budgets in climate models. 

Carbon isotope-constrained seasonality of carbonaceous aerosol sources from an urban location (Kanpur) in the Indo-Gangetic Plain: 14Capportionment of carbonaceous aerosol. Available from: https://www.researchgate.net/publication/315970418_Carbon_isotope-constrained_seasonality_of_carbonaceous_aerosol_sources_from_an_urban_location_Kanpur_in_the_Indo-Gangetic_Plain_14Capportionment_of_carbonaceous_aerosol [accessed Jun 2, 2017].},
	doi = {10.1002/2016JD025634},
	url = {http://doi.wiley.com/10.1002/jgrd.v122.9http://doi.wiley.com/10.1002/2016JD025634http://onlinelibrary.wiley.com/wol1/doi/10.1002/2016JD025634/fullpdfhttps://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002\%2F2016JD025634},
	author = {Bikkina, Srinivas and Andersson, August and Ram, Kirpa and Sarin, M. M. and Sheesley, Rebecca J. and Kirillova, Elena N. and Rengarajan, R. and Sudheer, A. K. and Gustafsson, {\"O}rjan}
}
