The Norunda research station was established in 1994. Since 2013 it is a combined atmospheric and ecosystem measurement station within the Integrated Carbon Observation System (ICOS) Sweden network. In 2018 the station was labeled as a class 1 atmospheric station and class 2 ecosystem station within the European ICOS network.
The site is located approximately 30km north of Uppsala (60°05′N, 17°29′E, 46 m above mean sea level) within the southern extent of the boreal forest zone. Norunda is operated by Lund University (LU) and welcomes collaborations from external research groups (ongoing project collaborations include ACTRIS and EMEP). The station PI is LU Assoc. Prof. Meelis Mölder and two LU research engineers are stationary at Norunda: Dr. Irene Lehner and Anders Båth.

The station features a facility and a 102 m-high tower surrounded by 100-120 year old trees reaching up to 25-30 m in height. Beginning in 2021/2, the area ca. 300 m around the mast will be turned into a clear cut as the trees have long reached the age of harvesting.

The site hosts (since March 2019) a 94 GHz cloud radar - including a passive 89 GHz radiometer channel – and a disdrometer as part of the FRM4RADAR project. The project aims to develop a network of reference sites across Europe to produce Fiducial Reference Measurements (FRM) for the evaluation of EarthCARE satellite observations. The cloud radar will be installed and managed by the Swedish Meteorological and Hydrological Institute (SMHI).

The following instruments are currently installed at the Norunda research station.

Precipitation instruments:

• ambrecht 15189H: heated tipping bucket. Tipping bucket volume: 2 cm3 (2 g). Sensitivity: 0.1 mm
• Genor T200BM: weighing gauge. Capacity: 1000 mm. Sensitivity: 0.1 mm. With ALTER wind shield
• SMHI can: tipping bucket rain gauge for backup

Snow height:

• Campbell SR50ATH: heated sonic distance sensor for determining snow depth. It emits an ultrasonic pulse and then measures the elapsed time between the emission and return of the pulse. An air temperature measurement is required to correct for variations of the speed of sound in air. The SR50AH includes an integrated heater that prevents ice and rime from coating the transducer. Resolution: 0.25 mm

Mast:

• 102 m height tower. 14-level profile system: 12 levels along the mast + 2 levels close to the ground on a small tower about 25 m away from the main tower.
• 1) Flux system
  • Licor Li7200 Enclosed CO2/H2O Gas Analyzer: high speed, high precision, non-dispersive infrared gas analyzer
  • Metek uSonic-3 Omni anemometer: 3-axis sonic anemometer. U, V, W vector outputs. Range: 0-60m/s wind speed, 0-360° wind direction
  • Thermocouple type T for air temperature measurements
• 2) Radiation
  • Kipp&Zonen CNR4: net radiometer measuring the radiation balance between incoming short-wave and reflected long-wave Far Infrared (FIR) radiation versus surface-reflected short-wave and outgoing long-wave radiation. Spectral range:
  • short wave: 300 to 2800 nm
  • long wave: 4500 to 42000 nm
  • Kipp&Zonen CMP21: short wave incoming radiation (280 … 2800 nm) at 101.5 m height
  • Licor LI790/R: above canopy Photosynthetic Photon Flux Density (PPFD) measurement. No. 1 for incoming and no. 1 for reflected flux
  • Delta-T BF5 sunshine sensor at 101.5 m height
• Campbell SI-111 precision infrared radiometer: target (surface) temperature                    

Ceilometer:

Vaisala CL51: boundary layer and cloud height measurements. Reporting resolution: 10m; cloud reporting range: 0 ... 13 km; backscatter profiling range: 0 … 15 km. It employs a pulsed InGaAs diode laser, wavelength: 910 nm

Other instruments (ICOS + non-ICOS):

• Campbell CS450 (no. 1), Campbell CS451 (no. 2): ground water level measurement
• Vaisala PTB210: digital barometer for air pressure measurement
• Apogee SQ-110: quantum sensor for below-canopy (transmitted) PPFD measurement at about 1 m height. No. 16 deployed sensors
• Rotronic MP102H: air temperature and relative humidity measurement. Range: -40 ... 80°C/0 … 100%. No. 1 with Rotronic Hygroclip HC2 and no. 2 with Hygroclip HC2A-S3
• Hukseflux HFP01SC-05: soil heat flux measurement. No. 4 at -5 cm
• Delta-T Theta Probe ML2x: soil moisture measurement. No. 2 at -5 cm, no. 4 at -10 cm, no. 2 at -30 cm, and no. 2 at -50 cm
• Campbell 107 Probe: soil temperature measurement. No. 4 at -2 cm, no. 4 at -5 cm, no. 4 at -10 cm, no. 4 at -30 cm, and no. 4 at -50 cm
• Picarro G2401 CRDS Analyser: CO, CO2, CH4, and H2O concentration measurements. Intakes at three levels (32, 59, and 100m)
• 14C-Sampler built by Heidelberg university: Carbon-14 concentration measurement. Intake at 100 m