ARCTIC LTER DATABASE (1) FILE NAME: 99DLTLD (2) YEAR: 1999 (3) PI: GUS SHAVER (4) OTHERS: JIM LAUNDRE (5) BRIEF DESCRIPTION OF DATA FILE: Daily weather data file for Arctic Tundra LTER site at Toolik Lake. Included are daily averages and/or maximums and minimums of air, soil and lake temperature, wind speed, vapor pressure, and sum of global radiation and unfrozen precipitation recorded near Toolik Lake. (6) KEYWORDS: weather, temperature, wind, rain, daily (7) SITE TYPE: TERRESTRIAL (8) RESEARCH LOCATION: University of Alaska Fairbanks Toolik Field Station, North Slope of Alaska (68 degrees 38'N, 149 degrees 36'W) (9) EXPERIMENTAL DESIGN AND METHODS: Weather data has been collected at Toolik Lake by a Campbell 21x datalogger 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, 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 99DLTLH.DAT, the three hourly data are in 99DLTLO.DAT, and daily summaries are in 99DLTLD.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 (10) NOTES AND COMMENTS: Wind speed less than .447 is considered calm. Radiation data was not totaled for the winter months since no attempt was made to keep sensors snow and frost free. Lake temperature is measured near the lake depth sensor. Therefore the lake depth measurements give the depth at which lake temperature is measured. (11) VARIABLE DESCRIPTION: NOTE: All missing values are indicated by #N/A Variable Variable description Units YEAR Year in yyyy DATE Date dd-mmm-yyyy MONTH Month of collection integer ID Datalogger program step. integer JULIAN Julian date ddd RAIN Total daily rain mm AT 1M Daily average Air temp at 1 meter Celsius AT 5M Daily average Air temp at 5 meters Celsius ATMAX 1M Maximum temp at 1 meter Celsius ATMAX HR 1M Time of maximum air temp at 1 meter 2400 ATMAX 5M Maximum air temp at 5 meters Celsius ATMAX HR 5M Time of maximum air temp at 5 meters 2400 ATMIN 1M Minimum air temp at 1 meter Celsius ATMIN HR 1M Time of minimum air temp at 1 meter 2400 ATMIN 5M Minimum air temperature at 5 meters Celsius ATMIN HR 5M Time of minimum air temp at 5 meters 2400 WSMAX 1M Wind Speed Maximum at 1 meter meters/sec WSMAX HR 1M Time of wind speed Max at 1M 2400 WSMAX 5M Wind Speed Maximum at 5 meter meters/sec WSMAX HR 5M Time of wind speed Max at 5M 2400 time WIND SP 1M Daily average wind speed at 1 meter meters/sec WIND SP 5M Daily average wind speed at 5 meter meters/sec VAPOR Press Avg. Vapor Pressure at 5 meters millibars Pyr j/cm2 Total joules per sq cm per day joules/cm2/day Quantum Mol/m2 Photosynthetical Active Radiation (Mol/m2/day) Moss1 Temp Avg.Soil moss layer temperature - set 1 Celsius Soil1 Avg. Soil temperature at 5 cm - set 1 Celsius Soil1 10cm Avg. Soil temperature at 10 cm - set 1 Celsius Soil1 20cm Avg. Soil temperature at 20 cm - set 1 Celsius Soil1 50cm Avg. Soil temperature at 50 cm - set 1 Celsius Soil1 100cm Avg. Soil temperature at 100 cm - set 1 Celsius Soil1 150cm Avg. Soil temperature at 150 cm - set 1 Celsius Lake Temp Avg. Lake water temperature at approx. 2 meter (see notes) Celsius Comments Notes on data (12) CALCULATIONS Variable Formula VAPOR PRESS 5M: Daily average of the following hourly calculation. If Air Temp > 0 then (RH 5M/100) * 6.1121 * exp(17.368 * AIR TEMP 5M/(238.88 + AIR TEMP 5M)) If Air Temp < 0 then (RH 5M/100) * 6.1121 * exp(17.966 * AIR TEMP 5M/(238.88 + AIR TEMP 5M)) (Buck 1981). PYR J CM2 : Daily sum of PYRANOMETER * 0.3600 jcm2 * 1000 Watt/Kwatt QUANTUM Mol/m2: (Daily sum of Quantum)*60sec*60 min* 10^-6 umol/mol (13) FOR MORE INFORMATION, CONTACT: Jim Laundre or Gus Shaver Marine Biological Laboratory The Ecosystems Center 7 MBL St. Woods Hole, MA 02543 (508) 548-3705 (14) OTHER DATA FILES TO REFERENCE: 88DLTLD, 89DLTLD, 90DLTD, 91DLTLD, 92DLTLD, 93DLTLD, 94DLTLD, 95DLTLD, 96DLTOL, 97DLTLD, 98DLTLD (15) REFERENCE CITATIONS: (16) FORMAT OF VARIABLES: File Name: 99DLTLD.DAT File type: Comma delimited (17) NUMBER OF RECORDS: records 237 (18) STATUS: Type 1 ========================================= (19) FOR ARCHIVAL USE: DATE RECEIVED: Jun 99 DATA FILE ENTERED BY: Jim Laundre DATA FILE VALIDATION: NAME:Jim Laundre 14OCT99 LOG OF CHANGES AND COMMENTS: C