Flux Tower

For more information about the Flux Tower and data, please, contact CANDAC/PEARL site manager Dr. Pierre Fogal

Data
Eureka Flux Tower data archive, NOAA PSL

Figure 1.  Photo of Eureka Flux Tower looking towards the NE.

Since 2007, a 10 m flux tower (FT) has been operated as a part of PEARL. The tower is erected approximately 250 m NNE of the East end of the Eureka runway. Geographical coordinates of the FT are 79.9955 N, 85.7716 W. It is equipped with a suite of instruments to measure surface-atmosphere exchanges of energy and momentum by means of eddy covariance micro-meteorological method (Grachev et al., 2018). The suite includes temperature sensors, a 3-cup anemometer and vane, sonic anemometers, precipitation sensors, barometers, radiometers, a soil probe, and a gas analyzer. The gas analyzer has been used to measure CO2 and H2O concentrations in ambient air for better understanding of the atmosphere-surface CO2 flux. In 2014 the instrument suite was complemented with a Paroscientific micro barometer mounted 1 m above the surface. The micro barometer measures the atmospheric surface pressure at a frequency of 50 Hz and a resolution of ~0.01 Pa to detect rapid pressure variations associated with the fast gravity wave oscillations which are common in the boundary layer during winter (Chimonas, 2002). The FT instrumentation specification is given in Table 1.

The FT began as a joint effort between the National Oceanic and Atmospheric Administration and CANDAC within the framework of activities of the International Arctic Systems for Observing the Atmosphere (IASOA) to enhance Arctic atmospheric research (Uttal et al., 2016).

Figure 2.  The Flux Tower sensors are getting cleaned by CANDAC operator.

Table 1.  Eureka flux tower instrumentation.
InstrumentModelMeasurementLevel (m)Sampling rate
3-cup sentry anemometer & vaneR.M. Young: 03001-Lwind speed & direction11.11 min
High precision pyranometersKipp & Zonen: CM22total shortwave irradiance, downwelling & upwelling11.11 min
Precision infrared radiometerEppley:PIRtotal longwave irradiance, downwelling & upwelling11.11 min
Humidity and temperature meterVaisala: HMT337air temperature & relative humidity10.1 6.1 2.331 min
RTD temperature probeCampbell Scientific: 43347air temperature9.75 5.98 2.333 Hz
Fine-wire thermocoupleCampbell Scientific: ASPTC-Lair temperature9.1 6.1 2.331 min
Sonic anemometerMetek: uSonic-3 Scientificu, v, & w wind velocity, virtual temperature7.54 3.0710 Hz
Gas analyzerLicor: LI-7500CO2 & H2O concentration8.010 Hz
Ultrasonic snow depth sensorCampbell Scientific: SR50-L100snow depth2.31 min
BarometerCampbell Scientific: CS105atmospheric pressure2.01 min
Precision infrared thermocouple sensorCampbell Scientific: IRTS-Pground surface temperature3.21 min
Averaging soil thermocouple probeCampbell Scientific: TCAV-Lground temperature−0.051 min
Soil heat flux plateCampbell Scientific: HFT3-Lsoil temperature gradient−0.051 min
Thermistor stringMRCactive layer depth temperature− 0.05 to − 1.2 m1 min
MicrobarometerParoscientific: 6000-16Batmospheric pressure1.050 Hz