The ALPACA 2022 study was carried out from January 17th, 2022 through February 25th, 2022. Peer reviewed papers from the study are on the ALPACA-2022-Publications page.

The following principal investigators and their groups were involved in the study:

  • Becky Alexander, University of Washington
  • Cort Anastasio, University of California Davis
  • Stephen Arnold, U. Leeds, UK
  • Brice Barret, LAERO, France
  • Slimane Bekki, LATMOS, France
  • David Brus, Finnish Meteorologogical Institute, Finland
  • Laura Conner, Univesity of Alaska Fairbanks
  • Jessie Creamean, Colorado State University
  • Barbara D’Anna, LCE, France
  • Peter DeCarlo, Johns Hopkins University
  • Stefano Decesari, CNR, Italy
  • Jack Dibb, University of New Hampshire
  • Elsa Dieudonn√©, UCLO/LPCA, France
  • Antonio Donateo, CNR, Italy
  • Kathleen Fahey, EPA
  • James Flynn, Universtiy of Houston
  • Javier Fochesatto, University of Alaska Fairbanks
  • Robert Gillam, EPA
  • Lu Hu, University of Montana
  • Deanna Huff, Alaska DEC
  • Yugo Kanaya, JAMSTEC, Japan
  • Nathan Kettle, University of Alaska Fairbanks
  • Kathy Law, LATMOS, France
  • Damien Licina, EPFL, Switzerland
  • Jingqiu Mao, University of Alaska Fairbanks
  • Kerri Pratt, University of Michigan
  • Tjarda Roberts, France
  • Joel Savarino, IGE, France
  • Federico Scoto, CNR, Italy
  • Julia Schmale, EPFL, Switzerland
  • Manabu Shiraiwa, University of California Irvine
  • William Simpson, University of Alaska Fairbanks
  • Jason St. Clair, University of Maryland, Baltimore County
  • Jochen Stutz, University of California Los Angeles
  • Rodney Weber, Georgia Institute of Technology
  • Brent Williams, Washington University at St. Louis
  • Robert Yokelson, University of Montana

Measurements were made at multiple sites around Fairbanks. A listing of the measurements and groups making those measurements is below

House site (indoor and outdoor air sampling):

Particulate Matter:

  • Real-time non-refractory PM composition via HR-ToF-AMS, PM black and brown carbon, fast in/out, DeCarlo, JHU
  • Semi-volatile organic aerosol particles and gases via SV-TAG, slow in/out, Williams, WUStL
  • Real-time single-particle composition via ATOFMS, fast in/out, Pratt, U. Mich
  • Aerosol size distributions via SMPS and APS, fast in/out, Pratt and DeCarlo
  • Nanocluster aerosols via CPC, Size via SMPS, and fluorescent particles via WIBS, indoors, Licina, EPFL
  • Outdoor bulk PM sampling for reactive oxygen species (ROS) via EPR, Shiraiwa, UCI
  • Indoor size-resolved PM sampling via MOUDI, Shiraiwa, UCI
  • Indoor bulk filter ROS via DTT assay, Weber, GATech
  • Outdoor bulk and size-resolved PM ROS via DTT, Weber, GATech
  • Photooxidant and hydrogen peroxide production in PM2.5, Anastasio, UC Davis
  • Indoor and outdoor low-cost optical PM sensors, DeCarlo, JHU


  • Volatile organic carbon gases (VOCs) via PTR-ToF-MS, fast in/out, Hu, U. Montana
  • Reactive Gases: O3, NO, NO2, NOx, NH3, fast in/out, Yokelson, U. Montana, DeCarlo
  • Greenhouse Gases CO2, CH4, CO, H2O, fast in/out, DeCarlo, JHU

Downtown sites:

Particulate Matter:

  • Real-time non-refractory PM composition via ACSM at NCORE, Weber, GATech / Mao, UAF
  • PM2.5, PM10 via BAM, PM2.5 speciation on 24-hour filters, ADEC at NCORE
  • Real-time non-refractory PM composition via HR-ToF-AMS, D’Anna, France
  • Inorganic isotope composition (nitrate, ammonium), Savarino/Albertin, France
  • PM absorption and scattering (405, 870 nm; black carbon & brown carbon) via PAX and PAS, Yokelson, U. Montana
  • Inorganic ion composition via PILS-IC, Weber, GATech / Mao, UAF
  • Total ammonia, ions via mist chamber, Weber, GATech
  • Size-resolved sulfate isotopes via high-volume PM sampler, Alexander, U. Washington
  • Particulate mass and elemental composition via EDXRF, Creamean, CSU
  • Particle Ice nucleation measurements, on and offline, Creamean, CSU
  • Single-particle composition via electron microscopy of MOUDI samples, Pratt, U. Mich.
  • Water soluble ions in bulk aerosol (total PM) via filter / IC, Dibb, UNH
  • PM size distributions, total PM number concentration, black carbon in PM1, D’Anna, France
  • Size resolved water soluble ions and metals via MOUDI and PM2.5 filters, Weber, GATech
  • Photooxidant and hydrogen peroxide production in PM2.5, Anastasio, UC Davis


  • Volatile Organic Carbon / Particle organic composition via CHARON PTR-ToF-MS, D’Anna, France
  • Reactive gases: O3, SO2, CO, NOx, Simpson, UAF
  • High precision CO, Yokelson, U. Montana
  • NO2 isotope analysis via ChemComb denuder sampler, Savarino/Albertin, France
  • Formaldehyde (HCHO), St. Clair, UMBC
  • Gradients via low-cost gas sensor: NO, NO2, SO2, CO, O3 & PM, Roberts, France
  • CO2 gradient (3m and 23m on CTC roof), Simpson, UAF

Meteorological Measurements:

  • Temperature gradient (3m, 6m, 11m, 23m on CTC roof), winds on CTC roof, Simpson, UAF
  • Particle Water via wet/dry optical particle counters, Weber, GATech
  • Photolysis rate measurements for NO2 and other gases via radiometers, Flynn, U. Houston
  • Wind Lidar profiling (first half of study), Dieudonne, France

Snow sampling:

  • Snow ionic composition, surface and pits, Dibb, UNH

Downtown vertical gas gradient measurements:

  • Vertical distribution of pollution downtown to Birch Hill (200m above valley) via LP-DOAS, Stutz, UCLA
  • Birch Hill Ski Hut, in-situ ozone measurement, Simpson, UAF

UAF Farm Fields:

Ground-based Meteorological Measurements:

  • Surface turbulent fluxes via eddy covariance, radiation, RH, T, scilintometer, acoustic sounder, Fochesatto, UAF
  • Wind Lidar profiling (second half of study), Dieudonne, France
  • Standard meteorological station observations, Schmale, EPFL

Ground-based Particulate Matter and Gases:

  • Particle size distributions, PM composition via MOUDI, ozone, CO, Schmale, EPFL
  • Meteorological and particle turbulent fluxes via eddy covariance, Donateo, Italy
  • Aromatic VOC, organic molecular tracers, metals, ionic composition, oxidative potential via DTT, Decesari, Italy

Snow sampling:

  • Nitrate isotopes in snow samples, Savarino/Albertin, France
  • Ionic composition, metals, and organic tracers in snow samples, Scoto, Italy

Swiss tethered balloon, Helikite:

  • Swiss Helikite balloon payload including RH, T, wind speed, pressure, PM size and number via OPC, mini SMPS, and CPC, PM light absorption via STAP, offline sampling, CO2, O3, CO, Schmale, EPFL
  • CNR/CASPA (French) balloon payload: gas sensors for: Benzene, Toluene, Ethylbenzene, Xylene, O3, CO, NO, NO2, CO2, H2O, Decesari, Italy, Barret, France, Brus, Finland

Mobile measurements:

  • Mobile ice nucleation measurements, PM size distributions, temperature, RH, winds via mobile sampler, Creamean, CSU
  • Car-based-sampling spatial distributions of PM2.5 concentration, black and brown carbon, particle number, DeCarlo / Robinson, JHU

Poker Flat (regional background air site):

  • Inorganic isotope composition (sulfate, nitrate, ammonium) via high-volume sampler, particle number and size via Grimm, Savarino/Albertin, France
  • Carbon monoxide and black carbon long term measurements, Kanaya, JAMSTEC, Japan

Meteorological and pollution modeling:

  • Meteorological modeling for ALPACA-2022 using the Weather Research Forecast (WRF) for US EPA Chemistry Modeling (CMAQ) – R. Gillam, K. Fahey, US EPA
  • Meteorological modeling forecasts during ALPACA-2022 using the Weather Research Forecast (WRF) for plume modeling – LATMOS, J-P Raut, T. Onish LATMOS, France, R. Gilliam, US EPA
  • Emissions development for ALPACA-2022 and CMAQ modeling, G. Pouliot, US EPA, D. Huff, ADEC
  • Community Multiscale Air Quality Modeling System (CMAQ) modeling during ALPACA-2022, Fahey, EPA
  • Modeling air pollution and background Arctic Haze during ALPACA 2022 using the 3D chemistry-aerosol model WRF-Chem, Law/Brett/Raut, LATMOS, France and Arnold, U. Leeds, UK.
  • WRF-FLEXPART modeling of surface and power plant emissions during ALPACA-2022, Law/Brett, LATMOS, France and Arnold, U. Leeds, UK
  • PACT 1-D modeling of vertical variation in pollution downtown, Cesler-Maloney / Stutz / Simpson, UAF / UCLA
  • Chemical box modeling using BOXMOX, Brett/Law, LATMOS, France and Arnold, U. Leeds, UK
  • Aerosol isotope modeling using CiTTyCAT, Bekki, Albertin, Savarino IGE/LATMOS, France
  • Chemical modeling of PM acidity and chemistry using ISORROPIA / F0AM, Campbell/Mao, UAF

Links for field study participants:

Field sites
Housing for participants
Data repository (, requires login)
slack channel (requires login)
Shared planning documents (Drive, requires login)
Near-real-time data plots (

The public-facing website for the broader ALPACA effort is the FairAir website. See that site for more general information.

The news section of the ALPACA site also has some information about events and scientific findings.