Ice sheets and their relation to sea level Konrad Steffen CIRES/University of Colorado Northwest Greenland, north of Jakobshavn, Spring 2003

Atmospheric and Ice-Based Observations Assess and quantify the impacts of climatic variability and change on components of the cryosphere and their consequences for the climate system, and determine the stability of the global cryosphere. Science Objectives Global mean sea level has risen 10–25 cm over the last 100 years (thermal expansion of ocean water 2–7 cm). The most important contributor to the remainder is likely to be land ice. Of all the contributions to sea-level change, the largest uncertainty pertains to the Antarctic and Greenland ice sheets. However, glaciers in most mountain regions are known to be retreating, and they too make a significant contribution to sea level. To understand past and present sea-level variations and predict future change, it is essential to measure and explain the current state of balance of glaciers, ice caps and ice sheets.

Maximum Melt Area Extent in Summer 2002, 2003, …

Stability of Ice Masses Improved assessment of the Greenland ice sheet stability and vulnerability to climate variability.

Pan-Arctic Climate Observing System Monitoring of climate parameters in climate sensitive regions is essential. Most climate monitoring stations are coastal and do not represent the local climate on ice masses. Establish Pan-Arctic climate network for use of process studies and verification of regional and large-scale climate models. The network should include basic meteorological measurements as well as upper atmosphere (profile) measurements. Fast data dissemination is required (satellite link) from remote locations for targeted field maintenance.