Presentation and history

The station is relatively new. It was set up in 2015 to provide background environmental data for field experiments done in the research field at the Viikki campus of the University of Helsinki, Finland.

Because of budget restrictions and needs of different experiments, sensors have been added over the years to expand the range of measured variables. Initially the aim was to collect measurements only during the growing season or snow-free period. Currently part of the sensors work reliably year-round, but the solar radiation sensors still lack air blowers to clear the snow.

The measured variables are the basic weather ones plus variables of specific interest in agro-meteorology and plant ecology, with particular emphazis on solar radiation and its spectral and temporal variation. For most variables data are acquired and logged at much higher frequencies than at standard meteorological stations or agro-meteorological stations. The array of radiation sensors is also much more comprehensive and covers most wavebands of interest for plant ecology and plant photobiology.

At the core of the station is a high speed datalogger with analogue to digital converters (ADC) with 24 bit of precision and an input expansion module. These together with the use in part of sensors with built-in ADC attached using multiplexed serial digital communication (SDI-12 protocol) allows the acquisition of data for many variables and replicate sensors every 5 s and computation of summaries logged once per minute.

Figure View of the weather station.

Location

Future plans

At the very least we hope to maintain the station measureing the same variables as currently in the future. Plans are in place to add broad band light sensors with special entrance optics. Cylindrical diffusers for UV-B, UV-A and Blue light sensors are being custom developed by sglux in Germany, to meassure irradiance on the vertical plane. The idea is that these sensors will complement the usual cosine-corrected ones used to measure irradiance on a horizontal plane. Many plant surfaces as well as parts of the human body are exposed as vertical surfaces, so knowing they radiation they receive is important.

A more ambitious enhancement is to incorporate the measurement of spectral irradiance, at least during some part of the year. The idea is to use a new type of array spectrometer with a transmission manochromator grating and a cooled sensor array. An application for funding is under preparation and an spectrometer from one supplier will be tested in September 2021 to determine its suitability for this purpose.