Weather

Note: These data are provisional and not error checked!

Weather station time is set to Alaska standard time and is not adjusted for daylight savings. Data are hourly averages (air temperature, lake level, lake temperature, wind speed), sums (rain, radiation) or mean wind vector direction.

Contact UAF-IAB-TFS-Metstation@alaska.edu with any questions, comments, or requests regarding Toolik met station data.

Note: These data are provisional and not error checked!

Contact UAF-IAB-TFS-Metstation@alaska.edu with any questions, comments, or requests regarding Toolik met station data.

1 Note: During the snow-free season, plant growth may cause small positive snow depth values.

Weather Monitoring at Toolik Field Station

Weather data has been collected at Toolik Field Station (68 degrees 38'N, 149 degrees 36'W) since June 1988. The weather station located at the field station was originally installed by the Arctic LTER and TFS assumed control of the station in 2007. The field station is an ideal location for maintaining long-term weather data, as it is located in a data sparse region and adds a data point along the north-south transect of the Northslope of Alaska, following along the Dalton Highway. There is year round access and a long-term pre-existing dataset. These advantages make it possible to provide quality data - a often difficult achievement in remote northern latitudes in Alaska.

To access the historical data from this weather station, please refer to Weather Data Query.

Data collected includes air temperature, relative humidity and wind speed, wind direction, global solar radiation, photosynthetically active radiation, barometric pressure, precipitation, soil temperatures, lake temperature, lake depth, precipitation and evaporation pan depth and pan water temperature. Most sensors are read every minute and then averaged or totaled every hour. The exceptions are soil temperatures, lake temperature, lake depth, and evaporation pan depth and pan water temperature which are read on ten minute intervals and averaged every three hours. Pan evaporation and pan water temperature are only measured during the summer months. For photosynthetically active radiation sensor no attempt is made to correct for frost or snow on the sensors during the winter months. As of 2008, global solar radiation sensor is equipped with a heater and ventilation system to remain snow and frost free throughout the year. Years prior to 2008, the global solar radiation was not kept free from frost or snow. Please note this when viewing radiation data.

In 2011, a new RM Young "Alpine" anemometer was installed by Polar Field Services (CH2M Hill Polar Services). The anemometer is located on a 44'-tall mast and records wind data at 30-sec. intervals. To access these data, please go to APRS World website.

For other weather data in the area, please see the NWS weather data viewer found here.

Contact UAF-IAB-TFS-Metstation@alaska.edu with any questions, comments, or requests regarding Toolik met station data.

Annual Met Data Reports
Parameters Measured

Hourly: Readings taken every 30 sec and averaged or totaled every hour

  • Air temperature at 3 m and 5 m (°C)
  • Relative humidity 3 m and 5 m (%)
  • Wind speed at 5 m (from 3 different anemometers, m/s)
  • Wind direction at 5 m (from 3 different anemometers, degrees)
  • Barometric pressure (mbar)
  • Pyranometer: Global solar radiation (sky + sun - J/cm2/hr)
  • Four component net solar radiation (short and long wave incoming and outgoing, W/m2)
  • Diffuse solar radiation (W/m2)
  • Photosynthetically active radiation (PAR quantum - μmol/m2/s)
  • UV-A and UV-B (W/m2)
  • Lake PAR (μmol/m2/s)
  • Snow depth (m)

3-hourly: Readings taken every 10 min and averaged or totaled every 3 hours

  • Soil temperature (duplicates - °C) at surface and at 5, 10, 20, 50, 100, and 150cm depths
  • Lake temperature (single depth)
  • Lake water level (cm)
  • Evaporation pan depth (mm)

Daily averages: Daily averages or min/max measured from all sensors are complied and reported

  • Daily max air temp (°C)
  • Time of day for max air temp
  • Daily min air temp (°C)
  • Time of day for min air temp
  • Daily max wind speed (prop anemometer 1) (m/s)
  • Time of day max wind speed
  • Daily min wind speed (prop anemometer 2) (m/s)
  • Time of day min wind speed
  • Daily min wind speed (sonic anemometer) (m/s)
  • Time of day min wind speed

Datalogger: CR3000 Campbell Sci
14 differential (28 single-ended) analog input channels. 4 switched excitation outputs. 2 continuous analog outputs. 6 control ports. 4 pulse counting channels. 4 megabytes data storage memory. Extended range of -40°C to +85°C.

Multiplexer: AM25T, Campbell Sci.
The AM25T sequentially connects up to 25 thermocouples to a differential analog input on a CR800, CR850, CR10X, CR1000, CR3000, CR5000, CR7, or CR9000X datalogger. A PRT attached to the multiplexer's grounding bar provides a temperature reference for the thermocouple measurements. The heat capacity of the grounding bar and an insulated aluminum cover reduce thermal gradients along the length of the multiplexer. Reducing the thermal gradients allow more accurate measurements.

Pyranometer (Global Solar Radiation): Kipp & Zonen CMP-6
Spectral range 310 to 2800 nm. Sensitivity 5 to 20 μV/W/m2. Response time 18 s. Zero offset A ± 15 W/m2. Zero offset B ± 4 W/m2. Directional error (up to 80° with 1000 W/m2 beam) ± 20 W/m2. Temperature dependence of sensitivity (-10 °C to +40 °C) ± 4 %. Operating temperature range -40 °C to +80 °C. Maximum solar irradiance 4000 W/m2. Field of view 180°

Pyranometer/Pyrgeometer: Kipp & Zonen CNR-4
The CNR4 is a pyranometer and pyrgeometer pair that faces upward and a second pair that face downward. The pyranometers and pyrgeometers measure shortwave and long-wave infrared radiation, respectively. There is also an internal thermistor for temperature correction and a heater to prevent frost deposition. Spectral response: pyranometer 305 to 2800 nm, pyreometer 4.5 to 42 μm. Response time: < 18 s. Uncertainty in daily total: pyranometer < 5%, pyrgeometer < 10%. Operating temperature: -40° to 80° C.

Ultraviolet Pyranometer: Yankee Environmental Systems, Inc. UVA-1 and UVB-1
The UVB-1 and UVA-1 Pyranometers measure total irradiance from 280 to 320 nm and 320 to 400 nm, respectively. The instruments produce a high level 0-4 VDC output signal and are thermally stabilized for long term reference-grade measurements. Response time is approximately 100 ms.

Quantum Sensor (Photosynthetically Active Radiation): Li-Cor, Quantum. Model LI-190SB
Quantum measure photosynthetically active radiation (PAR) in μmol s-1 m-2. Specs: range 400-700nm wavelength. Sensitivity 8mA/1000 μmol s-1 m-2. Relative error less then ±10% for plant canopies or less then ±5% for growth chambers.

Underwater Quantum Sensor: Li-Cor Underwater Quantum. LI-192SB
Accurate measurement of PAR in Aquatic systems. Spec: Sensitivity 3mA/100mE s-1 m-2. Relative error less then ±5%. Temperature dependence ±0.15% per °C. Maximum pressure 800 psi.

Relative Humidity/Temperature: Vaisala HMP155A Temperature and Relative Humidity Probe
TEMPERATURE: Calibrated measuring range: -80 to +60°C. Accuracy at 20-60°C: ±(0.055 + 0.0057 × temperature)°C. Sensor type: Pt 100 RTD 1/3 class B IEC 751. RH: Measuring range: 0.8-100% RH. Accuracy at 15-25°C: ±1% (0 to 905), ±1.7% (90 to 100%). Response Time: 20 seconds (63% step change), 60 seconds (90% step change). Sensor type: HUMICAP®180R.

Wind Monitor: RM Young
Wind direction is determined by a potentiometer whose voltage is proportional to the direction of the vane. Range: 0° to 360° mechanical, 355° electrical (5° open). Starting Threshold: 1.1 m/s. Wind speed is determined by the frequency of a sine wave produced by a magnet on the propeller shaft. Range: 0-100 m/s, accuracy: ±0.3 m/s. There are currently two wind monitors at the same height for redundancy. Temperature range: -50°C to +50°C, assuming no rime.

Year-round Rain Gauge: Pluvio N Rain Gauge (OTT)
70.010.000B.E. (08.03.1995) Measures rainfall based on weighing principle.

Summer Rain Gauge: Texas Electronics, Inc. TE525(WS) (supplied by Campbell Scientific) Tipping Bucket Electric Rain Gauge
A complex spun collector funnel with a knife edge that diverts the water to a tipping bucket mechanism. For each tip a magnet causes an electronic pulse that is recorded. Each alternate tip occurs for each 0.01 inch of rainfall. Specs: Accuracy 1% at 2 inches/hr or less. Accurate Temperature Range: 0 - 37°C.

Snow Depth: Campbell Scientific SR50A Sonic Ranging Sensor
Snow depth is determined by sending an ultrasonic pulse to the surface and an electrostatic transducer that listens to the reflected echoes. Range: 0.5 - 10 meters, Accuracy: 0.4% of distance to target.

Thermocouples: Omega Engineering, Copper-Constantan wire
Range -200 to 350 °C. Limits of error: Standard wire 1.0°C or 0.75% above 0°C and 1.0°C or 1.5% below 0°C. Special wire 0.5°C or 0.4%.

Pressure Transducer: Druck , PDCR 930TI
5 psi: ± 0.5% F.S. Toolik lake depth.

Evaporation Pan: Novalynx 255-100
Evaporation gage measure water level in a standard U.S. Class A evaporation pan (size 25.4 cm H X 120.6 cm I.D.) and provides an output proportional to the level in the pan. Specs: 0-25 cm. Accuracy ±0.76mm.

Barometer: Campbell Scientific CS106 Barometric Pressure Sensor
Technical Description: Measures barometric pressure over 600 to 1060 mb range Accuracy is ±0.5 mb @ +20°C Manufactured by Vaisala, Inc.

Communication System (Radiotelemetry): Campbell Scientific
RF450 Radio transmitting to RF50 base station, and a direct Ethernet connection for redundancy.