Overview of the Alaskan Layered Pollution and Chemical Analysis (ALPACA) Field Experiment
Creators: name: Simpson, William R.
name: Mao, Jingqiu
name: Fochesatto, Gilberto J.
name: Law, Kathy S.
name: DeCarlo, Peter F.
name: Schmale, Julia
name: Pratt, Kerri A.
name: Arnold, Steve R.
name: Stutz, Jochen
name: Dibb, Jack E.
name: Creamean, Jessie M.
name: Weber, Rodney J.
name: Williams, Brent J.
name: Alexander, Becky
name: Hu, Lu
name: Yokelson, Robert J.
name: Shiraiwa, Manabu
name: Decesari, Stefano
name: Anastasio, Cort
name: D’Anna, Barbara
name: Gilliam, Robert C.
name: Nenes, Athanasios
name: St. Clair, Jason
name: Trost, Barbara
name: Flynn, James H.
name: Savarino, Joel
name: Conner, Laura D.
name: Kettle, Nathan
name: Heeringa, Krista M.
name: Albertin, Sarah
name: Baccarini, Andrea
name: Barret, Brice
name: Battaglia, Michael A.
name: Bekki, Slimane
name: Brado, T. J.
name: Brett, Natalie
name: Brus, David
name: Campbell, James R.
name: Cesler-Maloney, Meeta
name: Cooperdock, Sol
name: Cysneiros De Carvalho, Karolina
name: Delbarre, Hervé
name: DeMott, Paul J.
name: Dennehy, Conor J. S.
name: Dieudonné, Elsa
name: Dingilian, Kayane K.
name: Donateo, Antonio
name: Doulgeris, Konstantinos M.
name: Edwards, Kasey C.
name: Fahey, Kathleen
name: Fang, Ting
name: Guo, Fangzhou
name: Heinlein, Laura M. D.
name: Holen, Andrew L.
name: Huff, Deanna
name: Ijaz, Amna
name: Johnson, Sarah
name: Kapur, Sukriti
name: Ketcherside, Damien T.
name: Levin, Ezra
name: Lill, Emily
name: Moon, Allison R.
name: Onishi, Tatsuo
name: Pappaccogli, Gianluca
name: Perkins, Russell
name: Pohorsky, Roman
name: Raut, Jean-Christophe
name: Ravetta, Francois
name: Roberts, Tjarda
name: Robinson, Ellis S.
name: Scoto, Federico
name: Selimovic, Vanessa
name: Sunday, Michael O.
name: Temime-Roussel, Brice
name: Tian, Xinxiu
name: Wu, Judy
name: Yang, Yuhan
Publisher: name: ACS
Year: 2024

description: The Alaskan Layered Pollution And Chemical Analysis (ALPACA) field experiment was a collaborative study designed to improve understanding of pollution sources and chemical processes during winter (cold climate and low-photochemical activity), to investigate indoor pollution, and to study dispersion of pollution as affected by frequent temperature inversions. A number of the research goals were motivated by questions raised by residents of Fairbanks, Alaska, where the study was held. This paper describes the measurement strategies and the conditions encountered during the January and February 2022 field experiment, and reports early examples of how the measurements addressed research goals, particularly those of interest to the residents. Outdoor air measurements showed high concentrations of particulate matter and pollutant gases including volatile organic carbon species. During pollution events, low winds and extremely stable atmospheric conditions trapped pollution below 73 m, an extremely shallow vertical scale. Tethered-balloon-based measurements intercepted plumes aloft, which were associated with power plant point sources through transport modeling. Because cold climate residents spend much of their time indoors, the study included an indoor air quality component, where measurements were made inside and outside a house to study infiltration and indoor sources. In the absence of indoor activities such as cooking and/or heating with a pellet stove, indoor particulate matter concentrations were lower than outdoors; however, cooking and pellet stove burns often caused higher indoor particulate matter concentrations than outdoors. The mass-normalized particulate matter oxidative potential, a health-relevant property measured here by the reactivity with dithiothreiol, of indoor particles varied by source, with cooking particles having less oxidative potential per mass than pellet stove particles.