The meteorological station on the surface of Toolik Lake was first installed in the spring of 1998. Originally the station recorded air temperature, relative humidity, wind speed, and wind direction. In 1999, a Kipp and Zonen CM3 radiation instrument was added to record the downwelling and upwelling of longwave and shortwave radiation. Measurements of all variables are taken at a 30 second interval, averaged every 5 minutes, and logged into a Campbell Scientific CR10x datalogger or starting in 2007 a Campbell CR1000 datalogger.   The meteorological station is anchored in place as soon as possible in June (when ice is off lake) and remains in place until the Land-Water group leaves in August. This station measures air temperature and relative humidity (with Vaisala HMP45C), wind speed and direction (with Met One 014A anemometer) and radiation (with CM3 Kipp and Zonen Radiometer). The longwave radiation is corrected for instrument case temperature. The wind sensor is ~ 3.8 meters above the water surface, and the temperature sensor is ~2.5 m above the water surface. The upwelling radiation sensors are located ~50 cm above the water surface. http://ecosystems.mbl.edu/arc/landwater/lw_protocols.html   The 2009 data set contained errors in our raw data set, where the wind direction was always from 94.8 degreess with 0 m/s in speed.  these values would continue for extened periods of time, resulting in a loss of data.  We collorated the wind direction and speed from the TFS Climate Station (on land) with the data from the lake station to interpolate the missing values.  Please see the notes column to identifiy when this occured.