Daily Soil Temperature and Meteorological Data for Sites at Toolik Lake Alaska

Summary

This data set consists of daily air, water, and soil temperature, wind speed, vapor pressure, and the sum of global radiation and unfrozen precipitation data from the Toolik Lake area of Alaska between 1998 and 2002. The data includes readings from two sites: the main Toolik Arctic Long Term Ecological Research (LTER) Tundra site and the nearby Toolik Tussock Experimental plots site that includes soil measurements from fertilized and unfertilized greenhouse and "shadehouse" areas. this work was funded by the Arctic System Science (ARCSS) program.

Data loggers recorded soil temperatures at various intervals down to 150 cm. Air temperatures were recorded between 1 and 5 meters. All temperatures are given in degrees Celsius.

The data consist of 28 comma-delimited ASCII text files, and are available via ftp. Data files for each site contain slightly different meteorological parameters.

The research project was funded by the Arctic System Sciences (ARCSS) Program, grant number OPP-9810222.

Citing These Data:

Shaver, G. and J. Laundre. Daily Soil Temperature and Meteorological Data for Sites at Toolik Lake Alaska. 2003. Boulder, CO: National Snow and Ice Data Center. Digital media.

Overview Table

Category Description
Data format Comma-delimited text files
Spatial coverage and resolution Data were collected in the Toolik Lake area of Alaska, coordinates 68.63 N, 149.60 W
Temporal coverage and resolution Daily from 01 June 1988 through 30 August 2002
File naming convention YYYY = four-digit year
dltld = main LTER site
dltud = Tussock site
File size File sizes range from 43 to 95 KB
Parameters Soil, lake, and air temperature, wind speed, precipitation, vapor pressure, rainfall, quantum radiation
Procedures for obtaining data Data are available via FTP

Table of Contents

1. Contacts and Acknowledgments
2. Detailed Data Description
3. References and Related Publications
4. Document Information

1. Contacts and Acknowledgments:

Investigator(s) Name and Title:

Gus Shaver, Principal Investigator at the Marine Biological Laboratory, and Jim Laundre, Marine Biological Laboratory

Technical Contact:

NSIDC User Services
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
Boulder, CO 80309-0449  USA
phone: +1 303.492.6199
fax: +1 303.492.2468
form: Contact NSIDC User Services
e-mail: nsidc@nsidc.org

2. Detailed Data Description:

Format:

Tables in comma-delimited text format

File and Directory Structure:

There is one directory for each data collection site: main and tussock

File Naming Convention:

File names consist of the following elements:

YYYY = four-digit year
dltld = Main LTER site
dltud - Tussock site

Example data file names:

2002dltld.txt
1998dltld.txt
2002dltud.txt
1998dltud.txt

File Size:

File sizes range from 43 to 95 KB.

Spatial Coverage:

Data were collected in the Toolik Lake area of Alaska, coordinates 68.63 N, 149.60 W

Temporal Coverage:

Readings were taken between 1988 and 2002.

Temporal Resolution:

Measurements were recorded daily.

Parameter or Variable:

Parameter Description:

Soil, lake, and air temperature, wind speed, precipitation, vapor pressure, rainfall, quantum radiation.

Unit of Measurement:

All temperature measurements are given in degrees Celsius.

Parameter Source:

For both data collection sites, a Campbell 21x datalogger measured all weather variables in this data set. Various sensors were used to gauge the data, as follows:

Parameter Range:

The tables below for each site describe each parameter and the units of measurement used. These table columns correspond to the columns in the data tables.

Main LTER site:

Variable Variable Units
YEAR Year 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 temperature at 1 meter Celsius
AT 5M Daily average Air temperature at 5 meters Celsius
ATMAX 1M Maximum temperature at 1 meter Celsius
ATMAX HR 1M Time of maximum air temperature at 1 meters 2400
ATMAX 5M Maximum air temperature at 5 meters Celsius
ATMAX HR 5M Time of maximum air temperature at 5 meters 2400
ATMIN 1M Minimum air temperature at 1 meter Celsius
ATMIN HR 1M Time of minimum air temperature at 1 meter 2400
ATMIN 5M Minimum air temperature at 5 meters Celsius
ATMIN HR 5M Time of minimum air temperature 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 time
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/day Photosynthetical Active Radiation (Mol/m2/day)
Moss1 Temp Avg.Soil moss layer temperature - set 1 Celsius
Soil1 5cm 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 meters (see notes) Celsius
Comment Notes on data

Tussock site:

Variable Name >Variable description Units
YEAR Year YYYY
DATE Date DD-MMM-YYYY
MONTH Month
ID Program step that output the data
JULIAN Julian Date ddd
Rain Total daily unfrozen rain mm
CT TEMP 3M Daily average air temperature at 3 meters Celsius
MAX CT TEMP 3M Maximum temperature at 3 meters Celsius
MAX HOUR CT TEMP 3M Time of air temperature max at 3 meters 2400
MAX WIND SPEED 3M Wind Speed Maximum at 3 meter meters/sec
MAX HOUR WIND SP Time of wind speed Max at 3M 2400
MIN CT TEMP 3M Minimum air temperature at 3 meters Celsius
MIN HOUR CT TEMP 3M Time of air temperature min at 3 meters 2400
WIND SPEED 3M m/s Daily average wind speed at 3 meters meters/sec
GH TEMP Daily greenhouse air temperature Celsius
SH TEMP Daily shade house air temperature Celsius
CT Quantum mol/m2/day Control Quantum radiation per meter sq. per day moles
GH Quantum mol/m2/day Greenhouse Quantum radiation per meter sq. per day moles
SH Quantum mol/m2/day Shade house Quantum radiation per meter sq. per day moles
VAPOR PRES Avg. Vapor Pressure at 3 meters millibars
PYR J CM2 HR Total joules per sq cm per day joules/cm2/day
CT1 10cm Set 1 daily average soil temperature at 10cm Celsius
CT1 20cm Set 1 daily average soil temperature at 20cm Celsius
CT1 40cm Set 1 daily average soil temperature at 39cm Celsius
CT2 10cm Set 2 daily average soil temperature at 10cm Celsius
CT2 20cm Set 2 daily average soil temperature at 20cm Celsius
CT2 40cm Set 2 daily average soil temperature at 40cm Celsius
COMMENTS Comments about individual datum points

Sample Data Record:

Data are in tables. The following table is a sample of a data table from the Main LTER site. Note that this sample shows only a portion of the columns in the actual data.

DATE Rain AT 1M AT 5M ATMAX 1M ATMAX 5M ATMAX HR 5M ATMIN HR 1M Moss1 Temp Soil1 5cm Soil1 150cm
30-Apr-02 2.794 1.2 1.7 3.9 5 1934 434 -1 -1 -6
1-May-02 3.556 -4.9 -4.8 1.4 2 44 2025 0 0 -6
2-May-02 1.778 -8.8 -8.6 -3.2 -2 1835 2314 -1 -1 -5
3-May-02 0 -14.5 -14.3 -7.5 -7.5 847 2339 -3 -3 -5
4-May-02 0 -8.1 -7.9 -3.8 -3.7 1502 153 -4 -4 -5
5-May-02 0 -3.5 -3.2 1.5 1.6 1622 246 -4 -4 -5
6-May-02 0 -0.1 0.1 2.9 3 1539 106 -2 -2 -5
7-May-02 0.254 -0.9 -0.9 3 2.7 1619 316 -1 -1 -4
8-May-02 0 1.3 1.4 4.9 4.6 1550 16 0 -1 -4
9-May-02 0.254 2 1.9 5.4 4.6 1025 2301 2 0 -4
10-May-02 1.524 -0.9 -1.1 0.3 0.1 836 2247 1 0 -4
11-May-02 2.286 -0.8 -1.1 3 2.7 1816 2303 2 0 -3
12-May-02 0.508 -0.4 -0.5 3 2.6 812 301 2 0 -3
13-May-02 0 -3.2 -3.2 4.2 3.8 941 0 1 0 -3

Error Sources:

Missing data indicated with N/A.

Main LTER Site Notes and Comments:

Wind speed less than .447 is considered calm. For most years, radiation data were 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.

The following table details specific errors and comments for each year, which correspond to the Main LTER site data file for the same year.

Year Comments
1988 From June 1 to August 24 the 5 meter sensor was only at 3 meters. On August 24th the 3 meter temperature/ RH sensor was moved up to 5 meters for better separation for the possibility of calculating energy balance using Bowen ratio approach. For the winter, only the 5 meter temperature/RH, wind speed and direction, soil temperature, and lake temperature were recorded. For 5 meter air temperatures less then -40, a regression of 5 meter air temperature verse air TC (only used 0 to -35 for regression) was used to correct the air temperatures. The 5 meter air thermistor is only accurate to -40 Celsius. Missing data for air temperature and rain were estimated when possible. For small gaps the in the hourly data before and after were averaged. For larger gaps regressions were made with the Imnaviat data set (a weather station maintained by Hinzman and Kane, Water Research Center, University of Alaska Fairbanks, Fairbanks, AK 99775-5860, which is about 12 kilometers away and 200 meters higher).
1989 The precipitation tipping rain bucket has an Alter-type wind screen. For the winter of 88-89, only the 5 meter temperature/RH, wind speed and direction, soil temperature, and lake temperature were recorded. For 5 meter air temperatures less then -40, a regression of 5 meter air temperature verse air TC (only used 0 to -35 for regression) was used to correct the air temperatures. The 5 meter air thermistor is only accurate to -40 Celsius. Missing data for air temperature and rain were estimated when possible. For small gaps the in the hourly data before and after were averaged. For larger gaps regressions were made with the Imnaviat data set (a weather station maintained by Hinzman and Kane, Water Research Center, University of Alaska Fairbanks, Fairbanks, AK 99775-5860, which is about 12 kilometers to the east and 200 meters higher).
1990 The datalogger stopped collecting data during winter of 1990-91. This file has data from January through August of 1990. Tussock Station was used to estimate using regressions between the two sites for missing data values.
1991 The datalogger stopped collecting data during winter of 1990-91. Data from January to April are estimated from the Tussock station.
1992 Data is missing for the following periods: 92160 to 92175 - Data not saved before changing memory allocations in logger. 92189 to 92248 - Data logger not set in logging mode after trying to fix the lake quantum sensor. 92174 TO 92366 - AIR TC 1M is not working. Missing data for air temperature and rain were estimated when possible. For small gaps the in the hourly data before and after were averaged. For larger gaps regressions were made with the either Toolik Tussock site or Imnaviat data set (a weather station maintained by Hinzman and Kane, Water Research Center, University of Alaska Fairbanks, Fairbanks, AK 99775-5860, which is about 12 kilometers to the east and 200 meters higher).
1993 Data is missing for the following periods: 93014 to 93166 - Top tower blew off; 5 Meter - Temp, RH, Wind direction and Wind speed no good. Also caused 1 meter Temp, RH to be erratic from 93130-93166. Soil temperature for set 2 were out of range during the winter. Missing data for air temperature and rain were estimated when possible. For small gaps the in the hourly data before and after were averaged. For larger gaps regressions were made with the either Toolik Tussock site or Imnaviat data set (a weather station maintained by Hinzman and Kane, Water Research Center, University of Alaska Fairbanks, Fairbanks, AK 99775-5860, which is about 12 kilometers to the east and 200 meters higher).
1994
1995 Quantum mol/m2 was corrected for negative readings by adding 400 to the daily quantum sum.
1996 Lake and 50 and 100 cm soil thermocouples stopped working during the winter of 1996 because of a loose wire. Quantum mol/m2 was corrected for negative readings by adding 500 to the daily quantum sum.
1997 Data was lost from 168 to 176 when logger memory filled. Late August soil profile #1 at 50 and 100 cm could not be reset. They were put in at 20 cm shallower. Using set 2 for daily temperature.
1998 Maximum and minimum values are from minute readings and not from hourly averages except for TC 5M min which is from hourly averages.
1999
2000 Data logger stopped during winter, 24 Nov 2000 to 2 Jun 2001; using Wet sedge data logger to estimate 1 and 5 meter temperatures (regressed available 1 and 5 meter temperatures with wet sedge 3 meter temperatures). Imnavait rain gage used for precipitation.
2001 Battery lost connection with logger and no data was collected from 24 Nov 2000 to June 2001; The StowAway sensor was used to estimate the 1 meter air temperature and a regression between 1 m and 5m to estimate the 5 meter air temp. Where StowAway was missing or temperatures dropped below -37.2 the Wet Sedge air temperature was used.
2002 Battery lost connection with logger and no data was collected from 24 Nov 2000 to June 2001; The StowAway sensor was used to estimate the 1 meter air temperature and a regression between 1 m and 5m to estimate the 5 meter air temp. Where StowAway was missing or temperatures dropped below -37.2 the Wet Sedge air temperature was used. From 4 Jun 02 through 23 Aug 02 replaced 5 meter vapor pressure calculation with 1 meter. The 5 meter RH sensor was not working.

Tussock Site Notes and Comments:

For all years: Wind speeds less then .447 are considered calm. Only unfrozen precipitation is reported. The global solar radiation sensor data is not corrected for frost or snow on the sensors during the winter months, so use this only qualitatively. The quantum sensor data are also not corrected for a small negative offset. In the spring months, soil temperatures are problematic since frost heaving of the probes caused depth of measurements to change.

The following table details specific errors and comments for each year, which correspond to the Tussock site data file for the same year.

Year Comments
1990 Data collection for this site began 24 June 1990.
1991 Missing days:16 June hour 1600 to 21 June hour 1400 (Bad connection); 16 August hour 1100 to 19 August hour 1900; 9 November hour 0500 to end of year (Battery volts dropped below 9.7). Pyranometer had an offset of -0.008; data was not corrected. Quantum sensors would go negative during low light/darkness. Most of the time the offset was -2.236 but occasionally one would read >-44. The control RH sensor was faulty, never getting above 82%. Data are reported but not used in vapor pressure calculation.
1992 The data logger failed in winter 91-92. Battery voltage dropped below 9 volts. Last day collected was 9 November 1991. A new 21x was installed and the old one sent to be serviced. An error was made when setting up the new program - minute readings was averaged every minute. As a result data overflowed the memory and only one day worth of data was saved. The problem was corrected 11 July 1992. The control and shade RH sensor are faulty, never getting above 82%. Data are reported but not used in vapor pressure calculation.
1993 Data is missing between 1 January through 31 May 1993.
1995 Wind direction sensor stopped working in December Wind speeds less then .447 are considered calm. Due to a vole hole in one of the multiplexer snow melt water caused data lost from 23 May to 10 June. The multiplexer was remove and number of sensors reduced in the green and shade houses.
1996 Data was lost on 3 Jan to 20 Jan when a storage module became full and on 7 Jun to 15 Jun and 19 Aug to 23 Aug when the datalogger stopped recording .The soil probes are checked every August and adjusted if possible. The depth is indicated in the variable name. Control RH sensor was not working from Jan to Aug when the sensor was replaced.
1997 The soil probes are checked every August and adjusted if possible.
1998 In August 1998 all profiles were reset using a white fiberglass pole anchored approximately 75 cm in to the permafrost. Replicates were installed in average non-tussock microsites. In January, February and December there are some erratic soil temperatures that are unexplained. From late June to late July the connection to the multiplexer failed resulting in no soil temperatures for that period.

5. References and Related Publications:

See the Arctic LTER site for the hourly data and other weather data (http://ecosystems.mbl.edu/arc/default.htm).

6. Document Information:

Document Creation Date:

14 May 2003

Document Revision Date:

Document Review Date:

Document URL:

http://nsidc.org/data/docs/fgdc/ggd906_soil_weather_alaska/