Snow depth, air temperature, humidity, soil moisture and temperature, and solar radiation are measured by a basin-scale wireless-sensor network in the American River Hydrologic Observatory (ARHO). The wireless-sensor network is deployed across the upper, snow-covered areas of the American River basin from 1510 to 2723 m elevation on the western slope of the Sierra Nevada in California. The network comprises 13 sensor clusters (Schneiders, Echo Peak, MT Lincoln, Caples Lake, Alpha, Duncan Peak, Van Vleck, Dolly Rice, Onion Creek, Robbs Saddle, Talbot Camp, Owens Camp, Bear Trap) at different elevations. Each cluster comprises 10 wirelessly connected sensor nodes strategically placed with distinct elevation, canopy cover, slope, and aspect within a 1 km² area. These 130 spatially distributed sensor nodes measure snow depth, air temperature, relative humidity, soil moisture and temperature, and solar radiation at 15-minute intervals. Raw data (level 0) have been processed to level 1 (QA/QC) and level 2 (gap-filled, derived, model-ready). Time period: water year 2014 through water year 2017.

The wireless sensor network provides continuous observations with a high spatial and high temporal resolution by sensor nodes connected via Metronome systems (http://metronomesystems.com/). Each sensor node is equipped with an ultrasonic snow-depth sensor (Judd Ultrasonic Depth Sensor, http://juddcom.com/) and a temperature/relative humidity sensor (Sensirion SHT-15, https://www.sensirion.com/en/environmental-sensors/humidity-sensors/digital-humidity-sensors-for-accurate-measurements/). Soil volumetric water content and soil temperature (Decagon GS3, https://www.metergroup.com/environment/articles/meter-legacy-soil-moisture-sensors/) are measured at depths of 30 and 60 cm by nodes in five clusters. Solar radiation is measured by upward-pointing Hukseflux-LP02 pyranometers (https://www.hukseflux.com/products/solar-radiation-sensors/pyranometers/lp02-pyranometer) at nine clusters. The data processing procedure is described in Bales et al. (2018, https://doi.org/10.5194/essd-2018-69).

Time zone: Pacific Standard Time (PST).

Level 0: raw data from datalogger.

Level 1: QA/QC data at 15-min intervals.

Level 2: gap-filled data at 15-min intervals; and model-ready derived hourly and daily data.

Spatial Information of sensor nodes of the wireless sensor network is in the directory “Gis_sensor”.

Figures of all sensor data are placed in the directory “Data_plots”.

Photos for each cluster are placed in the directory “Site_photos”.

Please see README.md for additional information.