Climate Data from Barrow and Atqasuk Alaska 1995-2001

Summary

This data set presents various climate data from sites in Barrow and Atqasuk, on the Northern Slope of Alaska. Parameters include thaw depth, air temperature, precipitation, wind speed, light intensity, plant canopy temperature, soil temperature, soil moisture, soil salinity, and relative humidity. Data were collected between June 1995 and August 2001 by various sensors connected to data loggers. Air and soil temperatures are given in degrees Celsius and wind speed is measured in meters per second. All other parameter measurements are detailed in the documentation. Data are available via FTP.

The research project was funded by the Arctic System Sciences (ARCSS) Program, grant number OPP 9714103.

Citing These Data:

Webber, P.J., Hollister, R.D. 2003. Climate Data from Barrow and Atqasuk Alaska 1995-2001. Boulder, CO: National Center for Atmospheric Research, ARCSS Data Archive.

Overview Table

Category Description
Data format Text files
Spatial coverage and resolution Atqasuk: 70.48 N - 157.42 W
Barrow: 71.32 N - 156.62 W
Temporal coverage and resolution 20 June 1995 to 25 August 2001
File naming convention Year started to year ended, area/data type, version
For example: 1998-2001_Climate_v1.txt
File size File sizes range from 88 KB to 42.6 MB
Parameter(s) Hourly screen height temperature, precipitation, wind speed near the ground, light intensity, plant canopy temperature, soil temperature, soil moisture, soil salinity, and relative humidity. Daily and seasonal thaw depths.

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:

Patrick J. Webber, Professor
Department of Botany
Michigan State University
Robert D. Hollister
Doctoral Student
Department of Botany
Michigan State University East Lansing, MI, USA

2. Detailed Data Description:

Format:

Tables in text format

File Naming Convention:

File names consist of the following elements:

Element Example
Temporal Coverage 1995-2001
Area/Data Type Climate
Plot_Microclimate
Detail_Microclimate
Thaw
Version v1 = version 1

Data file in this data set:
1998-2001_Climate_v1.txt
1995-2001_Plot_Microclimate.txt
1998-2001_Detail_Microclimate.txt
1995-2001_Thaw_v1.txt

The climate file provides data on air temperature, precipitation, wind speed, and light intensity. The Plot Microclimate file provides data on plant canopy air temperature and relative humidity. The Detail Microclimate file provides measurements of plant canopy air temperature, soil temperature, soil moisture, and soil salinity. The Thaw file provides data on thaw depths.

File Size:

The four data files range from 88 KB to 42.6 MB

Spatial Coverage:

Southernmost Latitude: 70.48 N
Northernmost Latitude: 71.32 N
Westernmost Longitude: 157.42 W
Easternmost Longitude:156.62 W

Temporal Coverage:

Measurements were collected between 20 June 1995 to 25 August 2001

Temporal Resolution:

The following parameters were measured hourly:

air temperature (at screen height)
Precipitation
Wind speed near the ground
Light intensity
Plant canopy air temperature
Soil temperature
Soil moisture
Soil salinity
Relative humidity

Thaw depths were measured daily.

Parameter or Variable:

Parameter Description and Units of Measurement:

The following table describes each parameter and its source, range, and unit of measurement.

Parameter Source Unit of Measurement
Air temperature Model 107 Temperature Probe degrees Celsius
Precipitation TE525 Tipping Bucket Rain Gage at 25 cm height millimeters
Wind speed 03001 Wind Sentry at 13 cm height meters per second
Light intensity StowAway Light Intensity Logger lumens per meter
Plant canopy air temperature MRC Temperature Probe at canopy height 13 cm degrees Celsius
Soil temperature MRC Temperature Probe at ground surface to 45 cm below surface degrees Celsius
Soil moisture Vitel Hydra Probe at 7.5 cm below surface water fraction by volume (wfv)
Soil salinity Vitel Hydra Probe at 7.5 cm below surface sodium chloride (NaCl)(grams) per unit volume (liter)
Relative humidity StowAway Relative Humidity Logger at canopy height 13 cm percentage
Thaw depths Metal rod graduated by centimeters centimeters

Sample Data Record:

Data are in tables. Each file is slightly different (described later in this section), so the number and types of columns vary across locations and may include the following column headings:

SitCom The site (B=Barrow Alaska,A=Atqasuk Alaska)
and community 1(D=Dry Heath Tundra,W=Wet Meadow Tundra)
Year The year of the recording (1998-2001)
Julian Julian day (1-366)
Month Month of the year (1-12)
Hr Hour of the day (0-23)
TempT Air temperature (degree Celsius) at 1 meter height
Rain Precipitation (mm) at 25 cm height
Wind Wind speed (meters per second) at 13 cm height
LumSqm Light (log of lumens per square meter)

The following table describes the parameters for each file:

File nameSitesDatesParameters
1998-2001_Climate_v1.txtB=Barrow, A=Atqasuk, D=Dry Heath Tundra, W=Wet Meadow Tundra19 August 1998 to 25 August 2001screen height air temperature, precipitation, wind speed, and light intensity
1995-2001_Plot_Microclimate.txtB=Barrow, A=Atqasuk, D=Dry Heath Tundra, W=Wet Meadow Tundra, C=Control,E=Open-Top Chamber20 June 1995 to 16 August 2001plant canopy air temperature and relative humidity
1998-2001_Detail_Microclimate.txtB=Barrow, A=Atqasuk, D=Dry Heath Tundra, W=Wet Meadow Tundra, C=Control, E=Open-Top Chamber19 August 1998 to 25 August 2001plant canopy air temperature, soil temperature, soil moisture, and soil salinity
1995-2001_Thaw_v1.txt B=Barrow, A=Atqasuk, D=Dry Heath Tundra, W=Wet Meadow Tundra, C=Control, E=Open-Top Chamber21 June 1995 to 16 August 2001daily to seasonal thaw depths

Error Sources:

Missing data are indicated with -999.9

Quality Assessment:

According to the investigators, these data are version 1 data and are very likely to contain errors. Specifically, air temperature and relative humidity were recorded between every 10 to 72 minutes and averaged by the hour. When no data were recorded within an hour (for recording intervals of greater than 1 hour) or if the data were considered erroneous, the average of the hour before and the hour after is recorded. Data collection was during the summer only and begun when the site was established (usually within a 2 days of snow melt) and ends around the middle of August.

Soil temperatures were taken every 10 to 18 minutes and averaged and recorded every hour. Salinity measurements were taken every hour.

Precipitation data are not valid for winter months and most likely underestimate true precipitation during the summer due to frequency of fine mists and strong winds.

Light intensity data are of poor quality due to potential reflectivity from condensation over the recording device.

3. References and Related Publications:

The International Tundra Experiment, ITEX, was established in 1990 as a Man-And-the-Biosphere, Northern Sciences Network (MAB-NSN) initiative. Since then the program has grown rapidly and is today one of the most active international field programs in arctic ecology. The purpose of ITEX is to monitor the performance of plant species and communities on a circumpolar basis in undisturbed habitats with and without environmental manipulations. See http://www.systbot.gu.se/research/itex/itex.html for more information.

6. Document Information:

Document Creation Date:

16 May 2003

Document URL:

http://data.eol.ucar.edu/codiac/dss/id=106.ARCSS908