Investigating the relative contributions of power plant and surface emissions to air pollution in Fairbanks, Alaska during the wintertime ALPACA 2022 campaign

• Main Authors: Brett, Natalie, Law, Kathy S., Arnold, Stephen, Barret, Brice, Dieudonné, Elsa, Fochesatto, Gilberto, Gilliam, Robert, Onishi, Tatsuo, Bekki, Slimane, Schmale, Julia, Pohorsky, Roman, Baccarini, Andrea, d'Anna, Barbara, Temime-Roussel, Brice, Decesari, Stefano, Pappaccogli, Gianluca, Donateo, Antonio, Scoto, Federico, Cesler-Maloney, Meeta, Huff, Deanna
• Other Authors: TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institute for Climate and Atmospheric Science Leeds (ICAS), School of Earth and Environment Leeds (SEE), University of Leeds-University of Leeds, Laboratoire d'aérologie (LAERO), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physico-Chimie de l'Atmosphère (LPCA), Université du Littoral Côte d'Opale (ULCO), University of Alaska Fairbanks (UAF), US Environmental Protection Agency (EPA), Extreme Environments Research Laboratory (EERL), Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory of Atmospheric Processes and their Impacts (LAPI), Laboratoire Chimie de l'environnement (LCE), Aix Marseille Université (AMU)-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS), Istituto di Scienze dell'Atmosfera e del Clima Bologna (ISAC), National Research Council of Italy, Istituto di Scienze dell'Atmosfera e del Clima Lecce (ISAC), Alaska Department of Environmental Conservation
• Format: Conference Object
• Language: English
• Published: HAL CCSD 2023
• Subjects: [SDU]Sciences of the Universe [physics]; Arctic; Fairbanks; Alaska
• Online Access: https://insu.hal.science/insu-04135389; https://doi.org/10.5194/egusphere-egu23-6258

International audience Local air pollution sources in the Arctic lead to poor air quality in Arctic cities, particularly during the winter months. Fairbanks in central Alaska, is a prime example of such an Arctic city which suffers from acute wintertime pollution episodes. The topography of Fairbanks (situated in a basin), coupled with strong surface-based temperature inversions, contributes to stable meteorological conditions that hinder the dispersion of pollutants and surface temperatures reaching -40 °C. These harsh winter conditions result in enhanced domestic and power plant combustion emissions. Stable meteorological regimes are frequently interspersed with less stable episodes, resulting in vertical mixing between surface and elevated inversion layers. However, there are many uncertainties in our understanding about pollution sources and secondary aerosol formation under cold, dark winter conditions, where photochemistry is limited. These issues were addressed through the collection of comprehensive datasets on atmospheric composition and meteorology in Fairbanks, during the international ALPACA (Alaskan Layered Pollution and Chemical Analysis) field campaign in January and February 2022. Data were collected at the surface and vertical profiles were collected using a tethered balloon (EPFL Helikite).Here, we examine the relative contributions and distributions of power plant emissions, emitted above the surface, and surface emission sources to pollution levels in the Fairbanks region. The FLEXPART-Weather Research and Forecasting (WRF) Lagrangian particle dispersion model, driven by meteorological fields from WRF-Environmental Protection Agency (EPA, Alaska) simulations is deployed. Firstly, model runs are used to evaluate the transport and dispersion of emissions from power plants at several altitudes in and around Fairbanks. Surface-based and elevated temperature inversions, characteristic of the winter boundary layer in Fairbanks, are considered in a parameterisation of power plant plume injection ...