Overview of the Alaskan Layered Pollution and Chemical Analysis (ALPACA) Field Experiment

Area of Science:

• Atmospheric Chemistry
• Environmental Science
• Public Health

Background:

• Fairbanks, Alaska experiences significant winter air pollution challenges.
• Understanding cold climate pollution dynamics and indoor air quality is crucial for resident health.

Purpose of the Study:

• Investigate winter pollution sources and chemical processes in cold climates.
• Assess indoor air quality and its relationship to outdoor pollution.
• Study pollution dispersion under frequent temperature inversions.

Main Methods:

• Conducted the Alaskan Layered Pollution And Chemical Analysis (ALPACA) field experiment in Fairbanks.
• Utilized outdoor and indoor air monitoring, including tethered balloons.
• Employed transport modeling to identify pollution sources and measured particulate matter oxidative potential.

Main Results:

• High concentrations of particulate matter and volatile organic compounds were observed outdoors.
• Pollution was trapped below 73 meters due to stable atmospheric conditions and low winds.
• Indoor pollution levels, particularly particulate matter, increased significantly during cooking and pellet stove use.

Conclusions:

• Frequent temperature inversions severely limit vertical pollution dispersion in cold climates.
• Indoor activities like cooking and heating are major contributors to indoor particulate matter.
• Particulate matter from different indoor sources exhibits varying health-relevant oxidative potential.