Langtjern ecological monitoring site

Short description:

The ecological monitoring site Langtjern is a forested lake catchment in southeastern Norway at circa 500 to 700m elevation and is well-suited to study natural responses of water chemistry, element cycles and biology to large scale changes in our environment such as deposition of pollutants and climate change. Read more at
Langtjern ecological monitoring site. Photo: CIENS zoom

Major research issues/sites:

Monitoring of freshwater and climate research

Short technical description:

The Lake Langtjern buoy measures water temperature using a thermocouple at 8 different depths (0.5m, 1m, 1.5 m, 2m, 3m, 4m, 6m, 8m). Oxygen saturation is measured with a Aanderaa Optode 4175 at depths of 1m and 8m. At the lake outlet temperature is measured in air, water and soil (10 cm) using a thermocouple. pH is measured with a Honeywell Durafet II and conductivity with a Honeywell graphite electrode, both having a direct line transmitter (4-20 mA). Water level is measured with a pressure cell. Coloured dissolved organic matter (CDOM) is measured with a TriOS Microflu-CDOM (ex 370nm/em 460nm) (D, small sensor) and UV-absorption with a TriOS ProPS (190-360 nm) (D, large sensor) with a 1 cm light path.

Both have mechanical wipers to remove biofilm. Additionally water flow is measured at the inlet LAE03. A new weather station was installed at Langtjern in November 2012, replacing a station from 2011. Air temperature and relative humidity is measured using a Campbell Scientific CD215. Global radiation with a Apogee SP-212 sensor. A Young Model 05103-5 measures wind speed and direction. In addition a web camera is installed at the station (Campbell Scientific CC5MPX). A sensor monitoring precipitation (Geonor T-200B) will be installed at the station in the near future. For power generation in this remote area solar panels and a methanol fuel cell have been installed. A small cabin is set up by the outlet to house various instruments.

Specific features/uniqueness:

The catchment has not been disturbed by any direct human interference since early in the 20th century.

Options and conditions for visiting scientists:

Please enquire for more information.

Unit Cost of use and principles of costing:

On demand

centre running the infrastructure:

CIENS - Oslo Centre for Interdisciplinary Environmental and Social Research

type of facility:

Observatory / large-scale experimental field site


Dr. Heleen De Wit
Research Manager
Phone: +47 954 34 360