In-situ characterization of layered pollution in the wintertime Arctic atmosphere by small sensors

• Main Authors: Roberts, Tjarda, Cesler-Maloney, Meeta, Simpson, William, Mao, Jingqui, Barret, Brice, Bekki, Slimane, Temine-Roussel, Brice, D'ANNA, Barbara, Maillard, Julia, Ravetta, François, Raut, Jean-Christophe, Woods, Andy, Ioannidis, Eleftherios, Law, Kathy S.
• Other Authors: Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales Paris (CNES), Department of Chemistry and Biochemistry Fairbanks, University of Alaska Fairbanks (UAF), Laboratoire d'aérologie (LAERO), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales Toulouse (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), TROPO - LATMOS, Department of Earth Sciences Cambridge, UK, University of Cambridge UK (CAM)
• Format: Other/Unknown Material
• Language: English
• Published: HAL CCSD 2021
• Subjects: envir; geo; Arctic; Fairbanks; Arctic pollution; Alaska
• Online Access: https://doi.org/10.5194/egusphere-egu21-15351; https://hal-insu.archives-ouvertes.fr/insu-03194356

International audience During the Arctic winter, local emissions (e.g. from home-heating, traffic, power station or industry plumes) coupled to poor dispersion caused by strong temperature inversions can lead to severe air pollution events. For example, each winter, Fairbanks (Alaska) experiences high abundances of gaseous pollutants and particulate matter (PM), leading to air-quality exceedances. However, there is still limited knowledge on the coupled physico-chemical and dynamical processes that cause wintertime Arctic pollution and aerosol formation under the very cold and low light conditions, and where levels of oxidants such as ozone at the surface can become depleted under limited vertical mixing. Here, we demonstrate novel deployment of low cost small sensors measuring PM2.5, gases (CO, NO, NO2, O3) and meteorological parameters (P, T, RH) to characterize Arctic atmospheric composition and properties, including mapping vertical distributions.Our three-week pre-ALPACA (Alaskan Layered Pollution and Chemical Analysis) intensive field-campaign took place in downtown Fairbanks in Nov-Dec 2019. Small sensor temperature-dependencies were characterized by instrument cross-comparisons and correction-algorithms developed. Sensors were then deployed near-ground, on the roof of a 19 m building, and on a vertical pulley system set-up along the side of the building for vertical profiling. The small sensors show a strong capability to capture temporal variations in PM2.5, CO, NO and NO2 and O3, across a wide temperature range: surface gas and particle abundances became elevated during a cold-polluted period (temperatures as low as -30 C) and again became elevated during a subsequent warm-polluted period (temperatures around -3 C). Vertical profiling during the warm-polluted period identified strong temperature inversions associated with near-surface layers of high PM2.5 and CO that are distinct from an overlying clean, warm, humid air-mass. During the cold-polluted period, temperature inversions were present but less ...