Experimental Design/Sampling Description:
Weather data at Toolik Lake has been collected by the Arctic LTER since June 1988. The station is located about 50 meters south of the lake's edge in a sedge/moss (Tomenthypnum nitens-Carex bigelowii) vegetation. Sensors that are measured every minute and averaged or totaled every hour include: air temperature and relative humidity at 1 and 5 meters, wind speed at 1 and 5 meters, wind direction at 5 meters, global solar radiation, photosynthetically active radiation, barometric pressure, and precipitation. Sensors measured every 10 minutes and averaged every three hours include: soil temperatures, lake temperature, lake depth, and evaporation pan depth and pan water temperature. Pan evaporation are only measured during the summer months. The hourly data are in the file yyyyDLTLH.DAT, the three hourly data are in yyyyDLTLO.DAT, and daily summaries are in yyyyDLTLD.DAT. A second data logger about 700 meters from the main weather station logs air and soil temperatures and photosynthetically active radiation in the experimental treatment plots. Treatments include greenhouse, shading, and fertilization. In the control plot wind speed and direction, global solar radiation and unfrozen precipitation are also measured. This station is also used as a backup to the main weather station. The full description of the sensors and site is in file SENSORS.DOC. The original data is in file yyyyDLTDAT.ZIP which is archived at The Marine Biological Lab, Woods Hole, MA.

NOTES AND COMMENTS: Lake temperature is measured at the depth that lake depth measurement is made. Soil temperatures consist of two profiles in a moss dominated plant community. They are within 3 meters of the weather station. . See additional notes under Comments variable

On August 19-20, 2008 - the weather station underwent an upgrade to the main data logger to a Campbell CR3000. Wind speed at 1 m was removed; Wind speed at 5m was replaced Vaisala HMP45C. Pyranometer was replaced w/ Kipp and Zonen CMP6 (ventilation unit - year round numbers are now available). Temperature/RH at 1 m was removed and replaced w/ an RMYoung T/RH probe at 3 m. The multiplexer for thermocouples was replaced with a AM25T 25-Channel Solid-State Multiplexer. A Campbell 107 thermister probe was also added to measure lake temperature but was not hooked up until Aug 2009.

Note that the evaporation pan was not set up in 2008.
Corrected SOIL2 20CM and SOIL2 10CM which were switched when the new logger was deployed . Jim Laundre 21Oct 2010.