- Visit the GLIMS site
Glacier fluctuations are widely recognized as clear indicators of changing climate. Satellite remote sensing offers the opportunity to monitor glacier fluctuations on a global scale and thus the concept of a Global Land Ice Measurements from Space (GLIMS) project was initiated by the USGS and NASA.
The goal of GLIMS is to take advantage of plentiful satellite imagery and image processing software in order to build on and improve existing inventories of glacier data. This is being accomplished through a worldwide cooperative network (Regional Centers) who map and analyze glacier fluctuations in the geographic region of their particular expertise. Once these Regional Centers (RCs) were well established, existing glacier data, both older maps and more current satellite data, as well as newly generated data, quickly became available. The primary focus has been on utilizing ASTER (Advanced Spaceborne Thermal Emission and reflection Radiometer) data but other sensors (Landsat, SPOT, etc) are also being applied to GLIMS glacier mapping.
In 2003 the National Snow and Ice Data Center (NSIDC) at the University of Colorado, Boulder, received NASA REASoN support to archive and distribute GLIMS data products, and to develop the information systems and service capabilities to address strategic needs associated with the analysis of glacier fluctuations as an indicator of climate change. The primary goal of the REASoN GLIMS project at NSIDC was to design and construct a database that would include outlines of glacier boundaries, snowlines, supraglacial lakes and rock debris, and other glacier attributes. Each glacier snapshot is from a specific time, and the database is designed to store multiple snapshots representative of different times. In order to support easy and efficient access to appropriate cloud-free ASTER scenes by data providers and analysts, the GLIMS database contains approximately 247,000 ASTER browse images.
As of February 2011, the database contains information on more than 93,000 glaciers, or approximately half of the world's total. Data ingested into the GLIMS Glacier Database since January 2010 include data from Alaska, Argentina, Northern Chile, New Zealand, and Austria. Data expected to be submitted in the near future include updated inventories from China and Nepal , as well as approximately 20,000 new glacier outlines from the European Space Agency funded project "GlobGlacier" project over the European Alps, Greenland, Norway, Western Himalaya, Baffin Island, west coast of Greenland, and the Canadian Arctic islands. Other RCs continue to contribute glacier mapping data to GLIMS.
The GLIMS glacier database is being used in both regional and global scale studies. By enabling analysis of glacier surface area and distribution over elevation ranges, and how glacier surface area is fluctuating over time, GLIMS offers new insights on how this crucial aspect of the cryosphere is changing. Specific GLIMS data sets have supported recent research studies at NSIDC. One such application is the use of glacier area in combination with Shuttle Radar Topographic Mission (SRTM) topographic data to derive glacier hypsometry as input to area-distributed models for determining the contribution of glacier melt to stream flow in Nepalese basins. Another example uses GLIMS glacier outlines to assess the accuracy of an automated global glacier-mapping algorithm based on the coarser resolution imagery from MODIS.
GLIMS at NSIDC continuously seeks to improve the capacity for efficient glacier mapping by standardizing format, protocols and algorithms and by holding training workshops. A 2008 GLIMS workshop held in Boulder, Colorado resulted in specific recommendations for algorithms tailored to specific geomorphological conditions. Another workshop, held in Mendoza, Argentina in late 2010 focused on training South American researchers in remote sensing, image processing, and GPS field data acquisition techniques.
Data in the GLIMS glacier database are accessed regularly via Web interfaces by members of the scientific, education, media, and business communities. The visitation rate to http://glims.org has almost tripled since 2007, from 1000 to about 2800 visitors per month. With recently implemented base operations support from the NSIDC NASA DAAC, we continue to add analyses to the data holdings, to collaborate with, and make more explicit links to, other glacier databases, for example the World Glacier Monitoring Service (WGMS), and to improve user interfaces to allow the broadest possible use of the GLIMS database. Operation of GLIMS within the NSIDC DAAC will not change how GLIMS data are distributed to users or how we receive data from providers.
Richard L. Armstrong - PI Senior Research Scientist, CIRES/NSIDC, University of Colorado, Boulder