Why Asian Glaciers Are Not Melting
Published on by Water Network Research, Official research team of The Water Network in Academic
Team of Researchers in the U.S. Has Built a Model that Appears to Explain the Karakoram Anomaly—where Unlike Other Parts of the World, Its Mountainous Glaciers Are Not Melting
A subtropical fate for North American icebergs
Between 20,000 and 10,000 years ago, icebergs released from the ice sheet covering the eastern region of North America drifted as far south as Florida, reports a paper published online in Nature Geoscience .
Jenna Hill and Alan Condron used maps of the seafloor to the south of Cape Hatteras, North Carolina, to identify numerous long, narrow grooves that were carved out by icebergs. The shape and distribution of the scars implies they were made by icebergs up to 300 metres thick. Based on a numerical model of ocean circulation, the authors argue that the icebergs were carried there by a narrow cold coastal current formed during periods when water from the melting North American ice sheet was discharged to the ocean. Relatively small pulses of meltwater could have transported icebergs as far south as South Carolina, but icebergs only reached the Florida coast during periods of intense meltwater discharge.
Stable glaciers in Karakoram due to unique seasonal cycle?
Most snow and rain in the Karakoram area of the high-mountain region of Asia falls during the winter months, whereas in nearby mountain ranges, monsoon-driven summer precipitation dominates, finds a study published online in Nature Geoscience . The Karakoram region has been noted for its anomalously stable glaciers, and the findings suggest that these unusual annual snow- and rainfall patterns may be protecting Karakoram glaciers from mass loss in a changing climate.
Sarah Kapnick and colleagues used high-resolution climate model simulations covering the period from 1861 to 2100, as well as observations, to analyse the seasonal cycle of snow- and rainfall in the Karakoram range. For comparison, they also studied two nearby regions of high-mountain Asia where glaciers are losing mass. They find that in the Karakoram most precipitation falls as snow between December and May. Moreover, in their projections for the twenty-first century, there is little change in total precipitation each year in response to climate change. In contrast, in the nearby mountain ranges, where monsoon-driven summer precipitation dominates, overall snowfall is projected to decline over the next century whereas rainfall will increase.
Read More Related Content On This Topic - Click Here
Media
Taxonomy
- Research
- Glacier
- Climate Change