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ABoVE: Thaw Depth at Selected Unburned and Burned Sites Across Alaska

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Documentation Revision Date: 2024-02-06

Dataset Version: 1.0

Summary

This dataset provides thaw depth measurements made at seven locations across Alaska, during August 2016, June and September 2017, and July-August 2018. Three of the locations are paired unburned-burned sites. At each site, three 30-meter transects were established and thaw depth was measured at 1-meter increments along each transect using a 1.15 m T-shaped thaw depth probe. Locations were selected to investigate fire disturbance, to span the range of permafrost regions from continuous to sporadic, and to cover vegetation types from boreal forests, tussock tundra, upland willow/herbaceous scrub, and lowland fen and wet tundra sites across Alaska. The data are provided in comma-separated values (CSV) format.

There is one data file with this dataset in comma-separated (.csv) format.

Figure 1. Locations of thaw depth measurement sites. Five of the locations are paired unburned-burn sites and IMNH & IMNL sites that are very close together and appear as one symbol.

Citation

Natali, S., S. Ludwig, C. Minions, and J.D. Watts. 2023. ABoVE: Thaw Depth at Selected Unburned and Burned Sites Across Alaska. ORNL DAAC, Oak Ridge, Tennessee, USA. https://doi.org/10.3334/ORNLDAAC/1579

Table of Contents

  1. Dataset Overview
  2. Data Characteristics
  3. Application and Derivation
  4. Quality Assessment
  5. Data Acquisition, Materials, and Methods
  6. Data Access
  7. References
  8. Dataset Revisions

Dataset Overview

This dataset provides thaw depth measurements made at seven locations across Alaska, during August 2016, June and September 2017, and July-August 2018. Three of the locations are paired unburned-burned sites. At each site, three 30-meter transects were established and thaw depth was measured at 1-meter increments along each transect using a 1.15 m T-shaped thaw depth probe. Locations were selected to investigate fire disturbance, to span the range of permafrost regions from continuous to sporadic, and to cover vegetation types from boreal forests, tussock tundra, upland willow/herbaceous scrub, and lowland fen and wet tundra sites across Alaska.

Project:  ABoVE

The Arctic-Boreal Vulnerability Experiment (ABoVE) is a NASA Terrestrial Ecology Program field campaign being conducted in Alaska and western Canada, for 8 to 10 years, starting in 2015. Research for ABoVE links field-based, process-level studies with geospatial data products derived from airborne and satellite sensors, providing a foundation for improving the analysis, and modeling capabilities needed to understand and predict ecosystem responses to, and societal implications of, climate change in the Arctic and Boreal regions.

Acknowledgements

This project was funded by NASA ABoVE grant number NNX15AT81A.

Data Characteristics

Spatial Coverage:  Alaska

ABoVE Reference Locations:

     Domain: Core ABoVE
     State/territory: Alaska
     Grid cells: Ahh1Avv0Bh1Bv4, Ahh1Avv0Bh0Bv5, Ahh0Avv1Bh1Bv5Ahh0, Avv0Bh1Bv5, Ahh1Avv0Bh2Bv3, Ahh0Avv0Bh2Bv3

Spatial resolution: Multiple points at 1-m intervals along three 30-m transects

Temporal coverage: 2016-08-09 to 2018-08-28

Temporal resolution: Each site was sampled one or more times.  

Study Areas (All latitude and longitude given in decimal degrees)

Site Westernmost Longitude Easternmost Longitude Northernmost Latitude Southernmost Latitude
Alaska -163.2388 -146.5575 68.9911 61.2699

Data file information

There is one data file with this dataset in comma-separated (.csv) format: thaw_depth.csv.

The file contains measurements of thaw depth at 1-m intervals along three 30-m transects at various sites throughout Alaska. Coordinates were recorded for the start and end of every 30-meter transect.

Missing data are recorded as -9999.

Table 1. Variables in the data file thaw_depth.csv

Column Name Units/format Description
date YYYY-MM-DD Measurement date
site_name - Name of site where measurements were made
site_code - Abbreviated site name. See Table 2.
latitude degrees north Latitude in decimal degrees at the beginning and end of each sampling transect. Values only given for sample_location with values of 0 and 30. Other sample_location values are -9999.
longitude degrees east Longitude in decimal degrees at the beginning and end of each sampling transect. Values only given for sample_location with values of 0 and 30. Other sample_location values are -9999.
transect - Transect number, 1-3
sample_location m Measurement location along the 30-m transect, 0 to 30. There are 31 measurements per transect.
thaw_depth cm Measurement of thaw depth taken with probe
notes - Notes recorded during measurements. When a “rock” was encountered, thaw_depth was set to -9999. Other notes may describe surface features (e.g., tussock, tree well) that may indicate that the recorded value is not representative of the site transect. For some of the measurements, the depth exceeded the length of the probe.

 Table 2. Study site locations

Site Name / Code Latitude Longitude
Hess Creek Unburned (HCU) 65.5674 -148.9251
Hess Creek Burned (HCB) 65.5688 -148.9234
Nome Creek Unburned – Old (NCU-OLD) 65.2856 -146.5600
Nome Creek Burned – Old (NCB-OLD) 65.3401 -146.9100
Eight Mile Lake (EML) 63.8801 -149.2560
Bonanza Creek (BNZ) 64.6960 -148.3257
I-Minus Low (IMNL) 68.5593 -149.5160
I-Minus High (IMNH) 68.5571 -149.5329
YK Delta Unburned (YKDU) 61.2703 -163.2410
YK Delta Burned (YKDB) 61.2705 -163.2356
Anaktuvuk Unburned (AKU) 68.9299 -150.2798
Anaktuvuk Burned (AKB) 68.9908 -150.2702
Nome Creek Burned – New (NCB-NEW) 65.2860 -146.5583

 

Application and Derivation

These data are part of a larger study to investigate how the magnitudes, fates, and land-atmosphere exchanges of carbon pools are responding to environmental change, and the biogeochemical mechanisms driving these changes.

Quality Assessment

Not provided.

Data Acquisition, Materials, and Methods

Site Selection

Sites were selected to investigate fire disturbance, to span the range of permafrost regions from continuous to sporadic, and to cover vegetation types from boreal forests, tussock tundra, upland willow/herbaceous scrub, and lowland fen and wet tundra sites across Alaska.

Methods

Three 30-meter transects were established at each of the 13 sites (refer to Table 3). Transects were spaced approximately 10-30 m apart a site. Coordinates for the 0-m and 30-m end point locations were recorded. Thaw depth was measured and recorded at 1-meter increments along each transect using a 1.15-m T-shaped thaw depth probe. The ABoVE thaw depth protocol was followed, and thaw depth measurements were taken from the top of the moss layer when present. Measurements were made in August 2016, June and September 2017, and July and August 2018 for most sites (Table 3).

Table 3. Site Descriptions

Site Name 2016 Sampling Dates 2017 Sampling Dates 2018 Sampling Dates Description
Hess Creek Unburned August 9 June 10, September 10 & 15 July 5, August 27 The site is located just off the Dalton Highway between mile 11 and 12 within an unburned boreal black spruce forest. 
Hess Creek Burned NA June 10, September 15 July 5, August 27 The site is located just off the Dalton Highway between mile 11 and 12 within a burned boreal black spruce forest (1995).
Nome Creek Unburned – Old August 10 June 13, September 18 NA The site is located within the White Mountain Recreation Area on a south facing slope characterized by willow/herbaceous scrub vegetation.
Nome Creek Burned – Old NA June 13 NA The site is located within the White Mountain Recreation Area on a south facing slope characterized by willow/herbaceous scrub vegetation which had been previously burned (2004).
Eight Mile Lake August 11 June 9, September 20 July 4, August 26 The site is located off the Stampede Trail in Healy. The area is characterized by moist tundra and sedge/shrub vegetation.
Bonanza Creek August 23 June 6, September 17 July 6, August 26 The site is located near the Bonanza Creek LTER Site within a boreal black spruce stand.
I-Minus Low August 21 June 15, September 11 NA The site is located approximately 1-km off the Dalton Highway, a few miles south of Toolik Field Station. The station is in a lowland, wet sedge fen area (Riparian). Day of sampling not provided for June 2017. Date set to June 15, 2017.
I-Minus High August 21 June 15, September 11 NA The site is located approximately 1-km off the Dalton Highway a few miles south of Toolik Field Station. The station is located on top of a hillside, and is characterized by tussock tundra. Day of sampling not provided for June 2017. Date set to June 15, 2017.
YK Delta Unburned NA September 24 NA The site is located on the Yukon-Kuskokwim Delta characterized by wet tundra vegetation.
YK Delta Burned NA September 24 NA The site is located on the Yukon-Kuskokwim Delta characterized by wet tundra vegetation. The area has been previously burned (2015).
Anaktuvuk Unburned NA NA July 11 Located in an undisturbed area near the Anaktuvuk river north of Toolik field station. The vegetation at the site is characterized by moss and tussock tundra.
Anaktuvuk Burned NA NA July 11 Located near the Anaktuvuk river north of Toolik field station within the severely burned area of the 2007 Anaktuvuk river fire. The vegetation is characterized by moss and tussock tundra.
Nome Creek Burned – New NA NA July 7, August 28 Located less than a 1 km off the Steese Highway near mile 63. The station is in a burned area (2004), and the vegetation is characterized by willow/herbaceous scrub.

Data Access

These data are available through the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

ABoVE: Thaw Depth at Selected Unburned and Burned Sites Across Alaska

Contact for Data Center Access Information:

References

Not provided.

Dataset Revisions

Product Version Release Date Revision Note
1.0 2024-02-06 Additional data were added from additional sites.
1 2018-04-17 ORNL DAAC released Natali et al. (2018), Version 1.