Tools and Data
Google Earth is an online mapping and visualization software that enables users to combine geographic information with satellite imagery. It allows layering of images and provides the means to determine relationships between "stacked" visualizations. It reads formatted KML files. This tool provides users with a way of manipulating Earth views through rotating, tilting, and zooming in and out.
With Google Earth, the location of the boreholes can be seen on a globe, temperature trends and a permafrost map can be overlaid on the globe, and students can get a sense of where permafrost is located globally.
Tool BuilderGoogleHeadquartered in Mountain View, CA.
Google Earth is based on technology from Keyhole, a company which Google acquired in 2004.
Tool CostGoogle Earth is a free download offered by Google. Other, more powerful versions are available for purchase.
Tool HelpUser guide: http://earth.google.com/userguide/v5/
Microsoft ExcelMicrosoft Excel or similar spreadsheet program, such as Open Office. This chapter was written using Microsoft Excel 2008.
Tool BuilderMicrosoft Corporation
Home Page for Excel
Microsoft Excel is available as a free trial: http://office.microsoft.com/en-us/try/
Open Office can be downloaded for free from: https://www.microsoft.com/en-us/download/office.aspxTool Help
Excel help is available online Excel Help Page
Data Sources for Google Earth
The permafrost_eet.kmz file was constructed by Lisa Ballagh at NSIDC using the data sources described below. The GISS site was used to generate pictures of temperature trends, and these were then converted to display as kml file layers. The kml layer for the permafrost map is available separately from NSIDC.
Permafrost Extent from National Snow and Ice Data Center (NSIDC)http://nsidc.org/data/ggd318.html
The circumpolar permafrost and ground ice data contribute to a unified international data set that depicts the distribution and properties of permafrost and ground ice in the Northern Hemisphere (20°N to 90°N). The re-gridded data set shows discontinuous, sporadic, or isolated permafrost boundaries. Permafrost extent is estimated in percent area (90-100%, 50-90%, 10-50%, <10%, and no permafrost). Relative abundance of ground ice in the upper 20 m is estimated in percent volume (>20%, 10-20%, <10%, and 0%). The data set also contains the location of subsea and relict permafrost. the gridded data are gridded at 12.5 km, 25 km, and 0.5 degree resolution. The shapefiles were derived from the original 1:10,000,000 paper map (Brown et al. 1997)
GISS Surface Temperature Datahttp://data.giss.nasa.gov/gistemp/
Trends in surface air temperature from NASA's GISS (Goddard Institute for Space Studies) Surface Temperature Analysis.
Data Sources for Excel
Surface Temperature Data
The permafrost data collection for this EET chapter was compiled by Florence Fetterer at the National Snow and Ice Data Center with the ID number G02189.
The following two surface temperature datasets are used in Part 4 of the chapter in the Excel Spreadsheets. The two surface temperature data sources draw on the same single original source: data from the World Meteorological Organization (WMO) station network.
National Center for Atmospheric Research (NCAR) dataset 570
This world monthly surface station climatology has data for over 4700 different stations (2600 in more recent years). Data for some stations goes as far back as the mid-1700s. Most of the data was obtained directly from the National Climatic Data Center (NCDC), Asheville, North Carolina. However, much of the data prior to 1951 came from John Wolbach of Harvard College Observatory, who contracted to have this data entered at NCDC. The first six months of 1961 were entered at NCAR. Sharon Nicholson, Florida State University, provided African precipitation data to extend the records of over 250 stations. Dennis Shea, NCAR/CGD, has been a valuable source for data obtained directly from various countries.
National Oceanic and Atmospheric Association (NOAA) Global Historical Climatology Network (GHCN) dataset
The Global Historical Climatology Network (GHCN-Monthly) database contains historical temperature, precipitation, and pressure data for thousands of land stations worldwide. The period of record varies from station to station, with several thousand extending back to 1950 and several hundred being updated monthly via CLIMAT reports. The data are available without charge through NCDC's anonymous FTP service.
Soil Temperature Data
Zhang, T.Z. and O. Frauenfeld. 2009. Soil temperature station data from permafrost regions of Russia (selection of five stations), 1880s - 2000. Boulder, CO: National Snow and Ice Data Center/World Data Center for Glaciology. Digital Media.
Soil temperatures were measured at depths of 0.02 to 3.2 meters using bent-stem thermometers, extraction thermometers, and electrical resistance thermistors. Data coverage extends from the 1800s through 1990, but is not continuous. Data are not available for all stations for the entire period of coverage. For example, data collection began at many stations in the 1930s and 1950s, and not all stations continued taking measurements through 1990.
The soil temperature data for this chapter are a selection from a larger collection of 36 stations that has not been published as a dataset. Florence Fetterer, at the NSIDC, made the selection and added surface air temperature with the assistance of others at NSIDC.