Home >> Global Outlook for Ice and Snow >> Time series of freeze-up and break-up dates from selected Northern Hemisphere lakes and ...
File type Download Size Language
.pdf .pdf Download 4 mb -
.png .png Download 186 kb -
.jpg .jpg Download 115 kb -
Uploaded on Tuesday 21 Feb 2012 by GRID-Arendal

Time series of freeze-up and break-up dates from selected Northern Hemisphere lakes and rivers, 1846–1995

Year: 2010 Author: Hugo Ahlenius, UNEP/GRID-Arendal
Limited by the availability of detailed observations, most historical evaluations of changes in freshwater ice have focused on relatively simple characteristics, such as the timing of autumn freeze up and spring break up, and maximum ice-cover thickness. Based on 27 long-term (about 150-year) records from around the Northern Hemisphere, Magnuson and others (Figure 8.1) discovered that freeze up has been delayed by approximately six days per hundred years and break up advanced by a similar rate, resulting in an almost two-week per century reduction in the ice-covered season. Numerous other regional and continental studies have been conducted using the more spatially-detailed sets of observations available for the latter half of the 20th-century. Results reveal strong contrasts in freeze-up and break-up timing between decades and between regions (see box on spring temperatures and ice break up) largely paralleling trends in major atmospheric patterns that have produced regional climatic warming or cooling.
Views: 300     Downloads: 120     Rating: 3
Mean snow-cover extent in the Northern Hemisphere 1966-2006
Ice sheets, schematic illustration for Greenland and Antarctica
Major glacier hazard locations
Sea ice concentration change over the 21st century as projected by climate models
Glacier changes on Nevado de Santa Isabel, Colombia
Projected reduction in snow 2080-2100
Ice avalanches of the Nevados Huascarán in Peru
Projected winter temperature changes in the Arctic