Air Shed Description

The Puyallup Tribe reservation is located within the Puget Sound air shed and is greatly influenced by four factors: urban development, the Pacific Ocean, the mountains and the weather. During periods when our onshore airflow is interrupted, the combined effects of activities, the weather and topography lead to stagnation and rising air pollution. The Olympic Mountains to the west and the Cascade Mountain range to the east form the sides of a bowl where air pollution becomes trapped in the urban basin. Temperature inversions are relatively common in the Puget Sound area. It takes an extra push of marine air to flush the pollution out of our area; the arrows in the diagram below illustrate the on-shore marine airflows that help keep the Puget Sound area air clean: