Sierra Nevada Network
The Sierra Nevada Vital Signs Network (SIEN) consists of four NPS units, including Devils Postpile National Monument (NM), Sequoia & Kings Canyon National Parks (NPs), and Yosemite NP. Sequoia & Kings Canyon NPs and Yosemite NP are Class I air quality areas; Devils Postpile NM is a Class II area.
Sequoia & Kings Canyon NP and Yosemite NP have extensive air quality monitoring. All network parks are in ozone non-attainment areas. An ozone injury risk assessment indicates the risk of injury is high in all SIEN parks.
The Network map below provides information on air quality monitoring. Ozone, sulfur dioxide, dry deposition, and meteorology are collected by the Clean Air Status and Trends (CASTNet) and Gaseous Pollutant Monitoring (GPMN) networks. Ozone is also monitored with passive samplers and portable continuous analyzers. Wet Deposition is monitored through cooperation with National Atmospheric Deposition Program/National Trends Network (NADP/NTN). The Mercury Deposition Network (MDN), part of NADP, collects precipitation samples that are analyzed for mercury. Visibility is monitored as part of the Interagency Monitoring of Protected Visual Environments (IMPROVE). Additional details on these parameters are described in Air Quality Monitoring.
Air quality monitoring in or near the network is indicated on the map by symbols, with the blue line showing the approximate borders of the network. The legend shows the symbols for the type of monitoring present, with NPS park units in green. Class I areas have linkable access to ARIS information.