Recently, The Houston Museum of Natural Science has been working with the University of New Hampshire to create a new full-dome planetarium show – Ice Worlds (now showing). From the poles of the Earth to the exploration of other ice planets in our solar system, this film explores the state of ice and liquid water throughout the galaxy, and climate changes here on Earth. As part of the Ice Worlds program, we are featuring Ice Bulletins as visitors enter the planetarium theater. If you want to know what’s Hot on the Cold Poles, these are the best current events we have found.
(We are also fortunate to have blog posts from Chris Linder, a scientist currently studying glacial lakes in Greenland. He will be calling in to the museum for a live-from-the-ice Q&A session on July 21.)
|photo credit: Irotzabal|
1. Changing global temperatures have caused coastal erosion along the Artic Ocean and can cause increased storm exposure.
Coastal areas with open water have more potential for wave action (as well as flooding and hurricanes) than a frozen shoreline. Studies from 1950-2000 have indicated a warming trend in the Chukchi and southern Beaufort Seas, which corresponds to a decrease in sea ice coverage. Longer, warmer seasons translate to less ice, and more open water, which in turn leads to more waves, floods, and storms.
2. Increase in Russian river discharge to the Arctic Ocean.
The amount of water flowing through rivers to the Arctic Ocean in Eurasia has been increasing over the last 70 years. More recently, (2000-2004) this flow has increased even more. If the trend continues, some scientists predict this could impact the global climate, perhaps leading to the cooling of Northern Europe.
3. Greening of the Arctic “shrubiness”
The warming of the Alaskan Arctic during the past 150 years has accelerated over the last three decades. This is expected to increase vegetation productivity in tundra if shrubs become more abundant; indeed, this transition may already be under way, according to local plot studies and remote sensing.
|photo credit: untipografico|
4. Acceleration of Greenland ice sheet melt.
Using satellite radar interferometry observations of Greenland, scientists have detected widespread glacier acceleration below 66° north between 1996 and 2000, which rapidly expanded to 70° north in 2005. Accelerated ice discharge in the west and particularly in the east doubled the ice sheet mass deficit in the last decade from 90 to 220 cubic kilometers per year. As more glaciers accelerate farther north, Greenland’s contributions to sea-level rise will continue to increase.
The legendary passage was first navigated with great difficulty using a relatively small ship by explorer Roald Amundsen in 1903 to 1906. Predictions for the opening of the Northwest Passage have ranged from 2012 to 2080 at their most conservative. “We’re several decades ahead of schedule right now,” said Mark Serreze, a senior scientist at the University of Colorado’s National Snow and Ice Data Center, which monitors the region. Fully navigable, the Northwest Passage will make the trip 4,000 miles shorter for ships traveling between Europe and Asia, allowing them to avoid the Panama Canal. “The notion of coming to an ice-free Arctic Ocean even by 2030 is not totally unreasonable,” Serreze said.
|photo credit: myradphotos|
The US Department of the Interior listed the polar bear as a threatened species under the Endangered Species Act based on studies claiming the loss of sea ice threatens, and will likely continue to threaten, polar bear habitat. The studies cite differences in sea ice from the fall of 1979 to the fall of 2007 and projected declines in sea ice by the middle of the 21st century. Although some females use snow dens on land for birthing cubs, polar bears are almost completely dependent upon sea ice for their sustenance. Any significant changes in the abundance, distribution, or existence of sea ice will have effects on the number and behavior of these animals and their prey. Canada has listed the polar bear as a “species of concern” since 2002 and is currently conducting a status review as of 2008.
7. Shortening of winter season means less lake ice and shorter time to use ice roads.
The oil industry and support services withdraw water from freshwater lakes and ponds to build ice roads and pads in the Arctic for increased access to remote sites. This technique is important to the oil industry, in that it allows oil field development or maintenance, while avoiding the environmental disturbance associated with construction of gravel roads and pads. The decrease in the time during which ice roads can be used is due to a changing climate. Ice roads are constructed using water from ponds, lakes, and rivers. Rivers themselves are traversed using ice bridges. The industry must have all drilling equipment back to gravel bases before the ice road deteriorates. The season ends when the first ice bridge is washed out. The ice bridge failures are a function of melting further south in the stream’s headwaters.