Snow and Vegetation Measurements from Selected Sites Near Council, Alaska, USA, 2000-2002


A combination of snow depth, snow temperature, snow water equivalent (SWE), and albedo measurements were taken from the spring of 2000 to the fall of 2002 at five sites near Council, Alaska. The sites vary in land cover type from forest to tundra. The purpose of the investigation was to understand the potential effects of climate change on the region by measuring how conditions change along a vegetation gradient. These data, which characterize snow cover and snow-holding capacity of various vegetation types, can help scientists understand how key meteorological events impact the arctic landscape.

Data files, available for ordering through NCAR, are in Excel format and include plots of the data and supplementary data information.

Citing These Data

Sturm, M. 2005. Snow and vegetation measurements from selected sites near Council, Alaska, USA, 2000-2002. Boulder, CO: National Center for Atmospheric Research.

Overview Table

Category Description
Data format Data files are in Microsoft Excel format, maps are in TIFF format, and photographs are in JPEG format.
Spatial coverage and resolution The selected sites were located within the range of 64.5029° N to 64.9354° N and 163.6496° W to 163.7378° W. Measurements were taken at intervals that ranged from 0.5 m to 20 m.
Temporal coverage and resolution Data extended from 09 May 2000 to 03 October 2002.
Tools for accessing data Microsoft Excel Software, version 4.0 or later, is necessary for optimal plot viewing.
File naming convention File names reflect the type of data or variable measured and the year the data were collected.
File size The individual file sizes range from 20 KB to 13.3 MB with the entire data package size being approximately 67.1 MB. The data are distributed as a 30 MB zip file.
Parameter(s) Parameters include snow depth, snow temperature, albedo, snow water equivalent (SWE), and vegetation cover type.
Procedures for obtaining data Data are available for ordering through NCAR.

Table of Contents

1. Contacts and Acknowledgments
2. Detailed Data Description
3. Data Access and Tools
4. Data Acquisition and Processing
5. References and Related Publications
6. Document Information

1. Contacts and Acknowledgments

Investigator Names and Titles

Matthew Sturm
USA-Cold Regions Research and Engineering Laboratory (CRREL)-Alaska
Ft. Wainwright, Alaska, USA

Charles H. Racine
Ft. Wainwright, Alaska, USA

Glen Liston
Atmospheric Science Dept.
Colorado State University
Ft. Collins, CO, USA

Jon Holmgren
Ft. Wainwright, Alaska, USA

Tom Douglas
Ft. Wainwright, Alaska, USA

Ken Tape
Geophysical Institute
University of Alaska
Fairbanks, Alaska, USA

Peter Olsson
Experimental Forecast Facility
University of Alaska
Anchorage, Alaska, USA

Karl Volz
Experimental Forecast Facility
University of Alaska
Anchorage, Alaska, USA

April Cheuvront
Table Rock Middle School
Morganton, NC, USA

Paul Heflinger
Oregon State University
Corvallis, OR, USA

Technical Contact


This grant was supported by National Science Foundation (NSF) award OPP-9732077, Collaborative Research: Snow, Weather and Shrubs: Winter Pathways of Change in the Arctic. The research was part of the Arctic Transitions in the Land-Atmosphere Systems (ATLAS) program as well as the Arctic System Science (ARCSS) program.

2. Detailed Data Description


The data are organized in a series of Excel workbooks where each file contains multiple pages. Thus, each page contains the data or a data plot for a particular site. Most of the workbooks are specific to a particular snow year, 2000-2002. "Notes" pages, which provide subsequent information about the data and any error associated with the measurements, can be found in the front of several workbooks.

File and Directory Structure

The data files are organized in the following directories:


The two directories titled Maps and Photos supplement the data files. The Maps directory contains a base map and smaller maps of the different sites. Each map shows the orientation of the measurements taken at each site. The key for the maps is included in "BaseMap.tif." The Photos directory contains various photos associated with the data collection. The maps are in TIFF format, and the photos are in JPEG format.

File Naming Convention

Generally, file naming conventions include the variable and the year the measurements were collected. For example, "AlbedoLines2002.xls" contains albedo data collected at each site in 2002.

File Size

Data file sizes range from 20 KB to 13.135 MB; map files range from 813 KB to 10 MB; graphic files range from 342 KB to 1.1 MB.

Spatial Coverage

All study sites were located near Council, Alaska, USA. These sites had been previously used by other Arctic Transitions in the Land-Atmosphere Systems (ATLAS) research groups.

Southernmost Latitude: 64.5029° N
Northernmost Latitude: 64.9354º N
Westernmost Longitude: 163.7378º W
Easternmost Longitude: 163.6496º W

Spatial Coverage Map

Map of site locations

Click on the above graphic to see the full-sized image (650 x 968 pixels, 116.2 KB) showing the orientation of each site. The key is useful for knowing where the data for a specific variable were collected. This and other maps are available in the Maps subdirectory.

Spatial Resolution

Snow depth was measured at 0.5 m intervals along the 100 m lines and at 2 m to 5 m intervals along the "long lines" (300 m to 1000 m). Snow temperatures were collected at irregular spatial intervals along the long snow depth line. Researchers took snow cores for SWE measurements at intervals of 10 m or 20 m. Albedo was measured at 1 m intervals.

Temporal Coverage

Measurements began on 09 May 2000 and ended on 03 October 2002. The 100 m and "long line" snow depth measurements were collected from 09 May 2000 to 25 May 2002. Stake depth readings along the 100 m snow lines were taken from 05 December 2000 to 25 May 2002. Data loggers collected snow temperature data from 25 July 2000 to 03 October 2002. Albedo data were collected from 17 April 2001 to 27 May 2002. SWE was measured from 18 April 2001 to 25 May 2002. Data were collected on irregular temporal and spatial intervals.

Parameter or Variable

Parameter Description

Parameters include snow temperature (°C), snow depth (cm), SWE (cm), albedo, and vegetation cover type.

Parameter Range

Snow depth: 0 cm to 183 cm

Snow temperature: -38.58 °C to 52.13 °C

SWE: 4.1 cm to 44.6 cm

Albedo:  0 to 1

Sample Data Record

The following data sample is from the file "100mSnowDepthLines2001.xls," Blueberry site.

Distance 18-Apr-01 11-May-01 21-May-01 31-May-01 3-Jun-01 5-Jun-01 9-Jun-01 2-Dec-01
0.0 120.6 114.0 96.2 73 46 32 0 9
0.5 112.9 109.0 85.7 72 34 27 0 8
1.0 101.5 94.9 80.6 50 24 0 0 7

Error Sources

Please refer to the "Notes" page of each data file for information on error sources during measurements.

Quality Assessment

Snow Depth

The brush at the Bear Creek site was so dense that the researchers found it difficult to collect the 100 m line data. Thus, they did not collect data as often there. Furthermore, the Bear Creek site was flooded in 2002, forming an aufeis (new ice formed on top of old ice), which prevented snow depths from being recorded.

The "long line" data--position (UTM meters) and snow depth (cm)--have not been adjusted for the natural tendency of the operator to "wander" about a straight line. The plots were adjusted so that the raw data fit the actual length of the straight line, by forcing each line to a fixed length. Please see the "Plots" tab in the LongLines Excel files and refer to the "Notes" tab for further explanation.

Snow Temperature

The summer temperatures collected with the Campbell CR-10X data logger and thermistors have questionable accuracy due to lack of solar shielding. Because of a large number of equipment failures, large gaps exist in some of the snow temperature data records.


In several cases, the albedo meter was shaded, and/or the recorded value was greater than one. The actual albedo of the snow cover and vegetation is not known in such instances.

Snow Water Equivalent (SWE)

Air temperatures that were above freezing were a common source of error. The wet snow stuck to the core barrel resulting in low values. These data were noted as "bad samples".

Please refer to the "Notes" page of the data file for information on questionable data measurements.

3. Data Access and Tools

Data Access

Data are available for ordering through NCAR.


The entire data set is approximately 67.1 MB. The data are distributed as a 30 MB zip file.

Software and Tools

Microsoft Excel, version 4.0 or later, is necessary for optimal plot viewing, but users can view data in any spreadsheet software.

Related Data Collections

4. Data Acquisition and Processing

Sensor or Instrument Description

Snow Depth

At each of the five Council sites, the researchers laid out a 100 m line and marked it with 11 stakes to make each survey coincident. They collected data using a MagnaProbe, a device that automatically records snow depths with fractional millimeter precision and an accuracy of ±2.0 cm. They also measured snow depths using hand probes, which have an accuracy of ±1 cm. Using a tape measure, the researchers measured 0.5 m intervals. The resulting spacing accuracy was ±0.05 m. Each stake along the line had metric tape on it to indicate snow depth.

At all but the Blueberry site, the researchers laid out a longer traverse line for supplementary snow depth measurements. They extended "long lines" across various vegetation types, and their lengths varied from 300 m to 1000 m. Along each line, they used an automatic depth probe and a survey-grade Global Positioning System (GPS, Trimble Pro-XR) to measure snow depth at 2 m to 5 m intervals. In general, the position locations were accurate to ±0.5 m in both the x (easting) and y (northing) directions with a mean position error of 0.7 m.

Snow Temperature

At four of the five sites, mini-data loggers (Hobos, Onset Computer Corporation) collected in situ temperatures with an accuracy of ±1.0 °C. Twenty Hobos mounted on rebar posts were scattered along the "long lines" and placed in a variety of vegetation landscapes. The researchers measured temperatures at the snow-ground interface.

At the Forest, Ophir, and Blueberry sites researchers used Campbell CR-10X data loggers and thermistor probes to measure the snow temperature. The thermistor probes had an accuracy of ±0.1 °C. They installed series of thermistors on thin horizontal rods projecting from a vertical pole. Thermistors embedded in the snow measured the snow temperature as a function of height during the winter.


At each of the five Council sites, the researchers set a 50 m cable in close proximity to the 100 m snow depth line. They suspended the cable between two poles over "typical" vegetation for each site and used a come-along to tighten the cable. Each cable had swedges (cable connectors) attached at 1 m intervals where the albedometer was positioned. During the melt period, two Kipp and Zonen CM7Bs recorded albedo periodically; one pointed upward and the other pointed downward. This albedometer was mounted on a wheel trolley that traveled along the cable. The instrument read the average albedo over a 10-second period after equilibrating. They also collected coincident vertical photographs of the ground and vegetation beneath the trolley.

Snow Water Equivalent (SWE)

At each of the five Council sites, the researchers collected snow cores along the 100 m snow depth line using a Federal Sampler instrument with a cross-sectional area of 11.5 cm2. They took snow cores with a vegetation plug in the core barrel, and they transferred each core to a plastic bag and weighed it on a digital balance with an accuracy of ±0.01 g. They generally obtained data in groups of two at intervals of 10 m or 20 m. They determined the depth at each core hole using a graduated pointed probe rod. Based on the depth and weight of the core, the bulk density of the snow along with the total SWE were ±5 %.

5. References and Related Publications

No references or related publications are currently available.

6. Document Information

List of Acronyms

The following acronyms are used in this document:

ATLAS: Arctic Transitions in the Land-Atmosphere Systems
ARCSS: Arctic System Science
CIRES: Cooperative Institute for Research in Environmental Sciences
CRREL: Cold Regions Research and Engineering Laboratory
FTP: File Transfer Protocol
GPS: Global Positioning System
NSF: National Science Foundation
NCAR: National Center for Atmospheric Research
SWE: Snow Water Equivalent
UTM: Universal Transverse Mercator

Document Creation Date

July 2005

Document Revision Date

July 2005

Document Review Date

July 2005

Document URL