Observations and Research
The main research aim at the site is to observe different atmospheric parameters relevant for climate change, regional pollution, atmosphere-ecosystem interactions, aerosol chemistry and physics based on long-term measurements. The specific research topics include formation and growth of aerosol particles, concentrations of aerosol particles of natural and anthropogenic origin, aerosol optics, atmospheric trace gases, grassland-savannah carbon balance, ecosystem interactions and water balance in a water-limited ecosystem.
Due to frequent lightning, the station is equipped with comprehensive incoming power and signal protections and it is built to start automatically after each power failure. The data are transferred wirelessly to a server for quality assurance.
The following continuous measurements are carried out on routine bases:
Measured property | Range/type |
Meteorology | Temperature, relative humidity, wind speed and direction, ambient pressure, vertical temperature gradient and precipitation |
Solar radiation | Incoming and reflected global radiation, incoming and reflected PPFD (PAR), diffusive radiation, net radiation |
Aerosol number size distribution | DMPS 10-840 nm |
Air ion size distribution | AIS 0.4-40 nm |
PM10 and BC monitors | SHARP and MAAP |
Trace gas concentrations | SO2, NO, NO2, O3, CO |
Aerosol scattering | 3-wavelength nephelometer |
Aerosol absorption | 7-wavelength aethalometer |
Vertical aerosol profile and PBL height | Vaisala CT25K ceilometer |
Soil moisture, soil temperature sensors and soil heat fluc | A range of different sensors: (at 5, 20 , 30, 40 & 50, 60 and 100 cm depth) |
Ecosystem flux measurements | H2O, CO2 and sensible heat fluxes (Li7000 + acoustic anemometer) |
SO2, NO2, CH4 and H2O vapour fluxes | Quantum Cascade Laser (Aerodyne) analyser |
Rain chemistry sampler | Inorganic ions, simple organic acid analysis of rain water |
In addition to the continuous measurements there have been short-term (one year or less) measurements of biogenic and anthropogenic VOC's, aerosol chemical composition and column concentrations of atmospheric trace gases. The Instrumentation for short measurement campaigns is described in Campaigns.
Changes in soil moisture and ecosystem CO2-flux after the beginning of the rainy season in November 2010.