High-Latitude Climate Transects

Science Center Objects

Legacy Data: High-Latitude Climate Transects

Disclaimer: This information was formerly hosted on the Alaska Geospatial Data Committee website.  It is presented here "as-is".  Please look for updated data elsewhere.

Project Description

Introduction

This project makes available datasets related to the High-Latitude Climate-Feedback Transects. These datasets cover a wide range of scales, from the entire Arctic circumpolar area, to several regional transects (Alaska, Eastern and Central Siberia), to very detailed ground data for a number of specific study sites.

Datasets Available

Within a transect, all of the datasets are the same size and co-registered with each other. The cell size (resolution) is approximately 1km, but varies between transects. Pay close attention to the units for each variable. Most have been re-scaled to maximize the amount of information, while minimizing the amount of disk space required (ie. byte rather integer or floating point). All datasets, except as noted, were built by M.D. Fleming.

Downloading Information

Most of the datasets consist of a basic raster image file with a number of image-related files. The related files include a short metadata description file, and all of the header and associated files required to read the images directly into ESRI's ARC/INFO software as a BIL image. The binary image file can be read by almost any image processing software. 

Not all datasets are currently available. As of 3/21/97 all of the Alaska datasets are available, including for the Climate variables. Several more Alaska datasets have been added for specific points, as well as the climate stations summaries used to calculate the climate surfaces. Most of the data is now available for the Russian Transects, but no vegetation. Workshop partipants who have problems downloading the data, or questions about the data may contact Michael Fleming at (mfimages@alaska.net).

 

Circumpolar Datasets

Download includes:

  • Vegetation - Draft Vegetation map of Circumpolar Region, [ 23 classes, 19 vegetated.] - not available
  • AVHRR Visible Band A - AVHRR band 1 composite image that was generated to minimize clouds using NOAA/AVHRR data.
  • AVHRR Near Infrared Band A - AVHRR band 2 composite image that was generated to minimize clouds using NOAA/AVHRR data.
  • Elevation - in meters above sea level.
  • Max Greenness - The maximum NDVI reflects the maximum photosynthetic activity for the growing season.

 

Regional Transect Datasets

Alaska Transect

Datasets available for the Alaska Transect. The actual datasets include more than just the transect and provide almost complete coverage for the state of Alaska. The datasets are in a standard statewide Albers Equal Area Projection, at a resolution of 1km. Each grid is 1992 lines by 2512 samples. Several of the datasets were developed from NOAA/AVHRR data and a derivative product, the Normalized Difference Vegetation Index (NDVI).

  • Vegetation - Vegetation map of Alaska, 23 classes, 19 vegetated.
  • CIR Image - A simulated color-infrared image was generated to minimize clouds using NOAA/AVHRR data.
  • Climate. The Climate data are available as a file containing all 12 datasets for each variable, with a metadata file. Each monthly dataset is approximately 5Mb when expanded (ie. 60Mb for each variable). The precipitation images (byte) are in units of 2 mm (ie. multiply by 2 to get mm of precip). The mean temperature images (byte) are in units of degrees C + 100 (ie a value of 100 = 0 degrees C). The range of temperature images (byte) are in 1/10 of a degree C (ie. a value of 100 = a range of 10.0 degrees C). The range temp data can be used to calculate average min and max temp's (ie. min = mean - (range/2) ). The climate data surfaces were generated by Wolfgang Cramer (ref).  This includes: Mean Precip, Range Temp, Mean Temp 
  • Elevation - in meters above sea level.
  • Slope - as percent grade.
  • Aspect - in 2 degree increments (ie. 0 & 180 = north, 90 = south).
  • Hydrologic Regions - The hydrologic sub-regions and sub-areas from USGS/WRD Alaska.
  • Soils - The sub-order soil classification, by ______.
  • PermaFrost - Permafrost classes, as mapped by O.J. Ferrians, 1965.
  • Onset Greenness - The time period in which the NDVI first rose above a threshold value (.10), corresponding to the time of emergence of vegetation.
  • Peak Greenness - The time period in which the maximum NDVI occurred and reflects the time of the year of maximum photosynthetic activity.
  • Duration Greenness - The number of days when the NDVI value reached or exceeded a threshold value (0.10) and is an estimate of the length of the growing season.
  • Max Greenness - The maximum NDVI reflects the maximum photosynthetic activity for the growing season.
  • Mean Greenness - The average cumulative effect of the NDVI for the growing season (May through September) and generally reflects total photosynthetic activity or net primary productivity.
  • Toolik Lake "Pixel" - Summary table of all variables listed above for the pixel that contains the Toolik Lake LTER "tussock tundra" site.
  • Bonanza Creek "Pixel" - Summary table of all variables listed above for the pixel that contains the Bonanza Creek LTER climate station site,"LTER1".
  • Climate Stations Data - Monthly tables for each station listing average climatic values for each month, January thru December. The climatic variables included are the average min and max temperature, and average precipitation. Three datasets are included for each variable: average for the entire period that data is available, average for just the years 1930 to 1960, and average for just the years 1961 to present, typically, 1990. A header file is also included for each variable with the station number, station name, elevation, beginning and last year of average, latitude and longitude, and percent missing.

Eastern Siberia Transect

Datasets available for the Eastern Siberia Transect. The raster image datasets are in a geographic projection (lat/long), at a resolution of 30x60 arcseconds (average approximately 920 meters).

  • Vegetation - Draft Vegetation map, xx classes.
  • Climate. The Climate data are available as a file containing all 12 datasets for each variable, with a metadata file. Each monthly dataset is approximately 5Mb when expanded. The precipitation images (byte) are in units of 2 mm (ie. multiply by 2 to get mm of precip). The mean temperature images (byte) are in units of degrees C + 100 (ie a value of 100 = 0 degrees C). The range of temperature images (byte) are in 1/10 of a degree C (ie. a value of 100 = a range of 10.0 degrees C). The range temp data can be used to calculate average min and max temp's (ie. min = mean - (range/2) ). The climate data surfaces were generated by Wolfgang Cramer (ref).  This includes: Mean Precip, Range Temp, Mean Temp 
  • Elevation - in meters above sea level.
  • Slope - as percent grade.
  • Aspect - in 2 degree increments (ie. 0 & 180 = north, 90 = south)
  • Climate Station Summaries - Monthly tables for each station listing average climatic values for each month, January thru December. The climatic variables included are the average min and max temperature, and average precipitation. Three datasets are included for each variable: average for the entire period that data is available, average for just the years 1930 to 1960, and average for just the years 1961 to present, typically, 1990. A header file is also included for each variable with the station number, station name, elevation, beginning and last year of average, latitude and longitude, and percent missing. 

Central Siberia Transect

Datasets available for the Central Siberia Transect. The raster image datasets are in a geographic projection (lat/long), at a resolution of 30x60 arcseconds (average approximately 920 meters).

  • Vegetation - Draft Vegetation map, xx classes.
  • Climate. The Climate data are available as a file containing all 12 datasets for each variable, with a metadata file. Each monthly dataset is approximately 5Mb when expanded. The precipitation images (byte) are in units of 2 mm (ie. multiply by 2 to get mm of precip). The mean temperature images (byte) are in units of degrees C + 100 (ie a value of 100 = 0 degrees C). The range of temperature images (byte) are in 1/10 of a degree C (ie. a value of 100 = a range of 10.0 degrees C). The range temp data can be used to calculate average min and max temp's (ie. min = mean - (range/2) ). The climate data surfaces were generated by Wolfgang Cramer (ref).  This includes: Mean Precip, Range Temp, Mean Temp 
  • Elevation - in meters above sea level.
  • Slope - as percent grade.
  • Aspect - in 2 degree increments (ie. 0 & 180 = north, 90 = south)
  • Climate Station Summaries - Monthly tables for each station listing average climatic values for each month, January thru December. The climatic variables included are the average min and max temperature, and average precipitation. Three datasets are included for each variable: average for the entire period that data is available, average for just the years 1930 to 1960, and average for just the years 1961 to present, typically, 1990. A header file is also included for each variable with the station number, station name, elevation, beginning and last year of average, latitude and longitude, and percent missing.