Changing Weather Influences What We Hear in Remote Areas

Atmospheric inversions play a crucial role in shaping soundscapes.

By the editors of Park Science magazine

About this article

This article was originally published in the "Research Roundup" section of Park Science magazine, Volume 39, Number 1, Winter 2024-25 (January 15, 2025).

Riley Creek contributes to the soundscape of the Triple Lakes Trail in Denali National Park.

Image credit: NPS / Chris Grahn

The interior of remote national parks offers a tranquil experience many people treasure in their busy, noise-filled lives. Without the constant buzz of human activity, you begin to hear other things. Like faint bird calls, insect chirps, or the crisp crackle of rustling leaves. A droning aircraft overhead suddenly seems startlingly out of place. But in mountainous parks like Denali National Park in Alaska, natural sounds from things like flowing water and changing weather influence what noise we hear from aircraft or vehicles.

National Park Service scientists monitor, study, and try to preserve sounds in park units for the benefit of people and wildlife, just like they do with any other natural resource. So understanding how natural, ambient sounds vary helps park researchers improve their monitoring methods. A paper in the October 2024 issue of the Journal of the Acoustical Society of America reports that scientists studied how atmospheric conditions like inversions affect what we hear. Inversions occur when warmer air traps cooler air below it.

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The researchers found that inversions happened more often between 7:00 p.m. and 9:00 a.m. Strong inversions—temperature increases of more than 0.06°C per meter (about 0.03°F per foot)—raised sound levels by 10–15 decibels. These inversions reduced the seasonal variability in sound levels and made it easier to predict and account for noise from things like aircraft. The study shows that inversions play a crucial role in shaping soundscapes in Denali. It could help scientists develop methods for monitoring and mitigating noise pollution in similarly remote parks.

Betchkal and Hug. 2024. Influence of Atmospheric State on Variability of Long-Term Residual Ambient Sound Level Measurements in a Subalpine Valley. Journal of the Acoustical Society of America 156: 2877–2888.