Weather data has been collected at Toolik Lake by a Campbell 21x datatlogger since June 1988. 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, net radiation (Fritschen type), barometric pressure, and unfrozen 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. Net radiation and pan evaporation are only measured during the summer months. The hourly data are in the file 90DLTLH.DAT, the three hourly data are in 90DLTLO.DAT, and daily summaries are in 90DLTLD.DAT. A second Campbell 21x 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 90DLTDAT.ZIP which is archived at The Marine Biological Lab, Woods Hole, MA.

Notes: Wind speed less than .447 is considered calm. The datalogger stopped collecting data during winter of 1990-91. This file has data from January through August of 1990. A nearby station, Tussock Station, was used to estimate using regressions between the two sites for missing data values. See notes in Comments variable and 90DLTUD.DOC.

Sampling Description.

None