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 datalogger 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

CHANGES 2009: 'JULIAN' field changed to 'DAY OF YEAR'. Switched order of Soil temp columns 'Soil2 10cm' and 'Soil2 20 cm'. Deleted columns not in use.

Winter precipitation (precip when temp < approx 1 C) is always suspect. False precipitation events are common in winter.