Worldwide Glacier Monitoring - Present State and Current Challenges

Abstract

�ue to their proximity to melting conditions, glaciers are among the most climate-responsive components of the solid Earth and thus offer essential variables required for global climate monitoring. Worldwide collection of information about ongoing glacier changes was initiated in 1894 with the foundation of the International Glacier Commission at the 6 th International Geological Congress in Zurich, Switzerland. Today, the World Glacier Monitoring Service (WGMS; ) continues to collect and publish standardised information on ongoing glacier changes. WGMS is a service of the Commission for the Cryospheric Sciences of the International Union of Geodesy and Geophysics (CCS/IUGG) and maintains a network of local investigators and national correspondents in all the countries involved in glacier monitoring. The WGMS is in charge of the Global Terrestrial Network for Glaciers (GTN-G) within the Global Climate/Terrestrial Observing System (Haeberli et al., 2000). GTN-G aims at combining (a) in-situ observations with remotely sensed data, (b) process understanding with global coverage and (c) traditional measurements with new technologies by using an integrated and multi-level strategy (Haeberli, 2004). The WGMS hosts an unprecedented dataset of information about spatial glacier distribution and changes over time which is readily available to the scientific community and the public. At present, the database contains about 34,000 front variation and 3,000 annual mass balance observations for 1,725 and 200 glaciers, respectively (see figure on front page). The World Glacier Inventory (WGI, 1989) makes available information on location, classification, area, length, orientation and altitude range for over 71,000 glaciers (mainly from aerial photographs and maps). This corresponds to about 44% of the total number and 23% of the total area of all glaciers and ice caps worldwide (cf. estimates by Dyurgerov and Meier, 2005). The Global Land Ice Measurements from Space (GLIMS; http://nsidc.org/glims) initiative was designed to continue this inventorying task with space-borne sensors (cf. Kieffer et al., 2000) in close cooperation with the National Snow and Ice Data Center (NSIDC; ) and the WGMS. A new project (GlobGlacier), under the lead of F. Paul (University of Zurich), is proposed to the European Space Agency and aims at making a major contribution to the current GLIMS database (see pg 5).