Climate Crisis: Bigger Storm Waves and Glacier Collapse

glacier collapseClimate Change is a multifaceted issue, which is due to the fact that there is no single consequence that takes precedence over the others. However, one undeniable consequence is the effect rising sea levels will have, thanks to rising temperatures and melting polar ice caps. Unfortunately, a new paper from Eric Rignot at NASA’s Jet Propulsion Laboratory  claims that some glaciers in West Antarctica “have passed the point of no return”.

A section of glaciers along West Antarctica’s coastline on the Amundsen Sea was previously predicted to be solid enough to last thousands of years. However, the JPL report finds that the ice will continue to slip into the water and melt much faster than expected. These massive glaciers are releasing tremendous amounts of water each year, nearly the equivalent of the entire Greenland Ice Sheet. When they are gone, they will have increased sea-level by about 1.2 meters (4 feet).

NOAA_sea_level_trend_1993_2010Rignot and his team came to this conclusion after analyzing three critical factors of glacier stability: slope of the terrain, flow rate, and the amount of the glacier floating in the water. Flow rate was the topic of a paper Rignot’s team published previously in Geophysical Research Letters where they determined the flow rate of these Antarctic glaciers has increased over the last few decades. The current paper discusses the slope and how much of the glacier is actually floating on seawater.

The conclusion he and his team came to were quite dire. As he summarized it in a recent press conference:

The collapse of this sector of West Antarctica appears to be unstoppable. The fact that the retreat is happening simultaneously over a large sector suggests it was triggered by a common cause, such as an increase in the amount of ocean heat beneath the floating sections of the glaciers. At this point, the end of this sector appears to be inevitable.

rising_sea_levelsAnother recent study, which appeared last month in the journal Nature, addressed another major problem threatening the polar ice caps. This study, which was compiled by researchers from the National Institute of Water and Atmospheric Research and The University of Newcastle, found that ocean waves that are whipped up by storms hundreds or even thousands of miles away from Earth’s poles, could play a bigger role in breaking up polar sea ice and thus contributing to its melt more than had been thought.

According to the study, these waves penetrate further into the fields of sea ice around Antarctica than current models suggest, and that bigger waves might be more common near the ice edges at both poles as climate change alters wind patterns. Incorporating this information into models could help scientists better predict the patterns of retreat and expansion seen in the sea ice in both Antarctica and the Arctic — patterns that are at least partly related to the effects of climate change — the researchers say.

glacier_collapseSea ice, as its name would suggest, frozen ocean water is, and therefore differs from icebergs, glaciers and their floating tongues called ice shelves – all of which originate on land. Sea ice grows in the winter months, and wanes as summer’s warmth causes it to melt. The amount of ice present can influence the movement of ocean currents — on average, about 9.7 million square miles of the ocean is covered with sea ice, according to the U.S. National Snow and Ice Data Center (NSIDC).

Researchers in Australia and New Zealand wanted to see how the action of big waves — defined as those with a height of at least 3 meters (about 10 feet) — might play a role in influencing the patterns of retreat and expansion, and if they could help improve the reliability of sea ice models. Prior to this study, no one had measured the propagation of large waves through sea ice before because the sea ice is in some of the most remote regions on the planet, and icebreaker ships must be used to plow through the thick ice.

Live blog on Artic sea ice : Sea Ice MinimumTo conduct their research, Alison Kohout – of New Zealand’s National Institute of Water and Atmospheric Research and the lead author on the study – went on a two-month ocean voyage with her colleagues to drop five buoys onto the sea ice that could measure the waves as they passed. It is thought that the ice behaves elastically as the waves pass through, bending with the wave peaks and troughs, weakening, and eventually breaking.

What the team found was that the big waves weren’t losing energy as quickly as smaller waves, allowing them to penetrate much deeper into the ice field and break up the ice there. That exposes more of the ice to the ocean, potentially causing more rapid melting and pushing back the edge of the sea ice. The researchers also compared observed positions of the sea ice edge with modeled wave heights in the Southern Ocean from 1997 to 2009 and found a good match between the waves and the patterns of retreat and expansions.

NASA_arctic-antarctic-2012Essentially, more big waves matched increased rates of sea ice retreat and vice versa. And while they believe that this might be able to help researchers understand this regional variability around Antarctica, Kohout and other researchers agree that more work needs to be done to fully understand how waves might be influencing sea ice. Kohout and her colleagues are planning another expedition in a couple of years. and it is hoped that subsequent studies will help identify the relationship with larger ice floes as well as the Arctic.

One thing remains clear though: as we move into the second and third decade of the 21st century, a much clearer picture of how anthropogenic climate change is effecting our environment and creating feedback mechanisms is likely to resolve itself. One can only hope that this is the result of in-depth research and not from the worst coming to pass! It is also clear that it is at the poles of the planet, where virtually no human beings exist, that the clearest signs of human agency are at work.

And be sure to check out this video from NASA’s Jet Propulsion Laboratory that illustrates the decline of glaciers in Western Antarctica:


Sources:
iflscience.com, scientificamerican.com

 

Ice and Organics Found on Another Planet!

mercury_messengerYes, the announcement from the Curiosity team yesterday that no organics have been found on Mars (yet) certainly came as a big disappointment. However, people may be interested to hear that organic molecules were discovered on a different planet in our Solar System, along with water and ice. Would you believe it, the planet is Mercury? Yes, the world famous for lakes of molten metal and extreme heat may actually boast the building blocks of life.

This information is the latest to come from NASA’s MESSENGER spacecraft, which is now orbiting the closest planet to our Sun. It confirms what was postulated 20 years ago, after images were taken of the polar region and detected radar-bright materials which were beleived to be water and ice. And where water and ice occur, organic molecules are often sure to follow. Though Mercury boasts the hottest environment of any planet in the Solar System, the area in question lies within a permanent shadowed series of craters on the northern pole.

Scientists today said that Mercury could hold between 100 billion to 1 trillion tons of water ice at both poles, and the ice could be up to 20 meters deep in places. Additionally, intriguing dark material which covers the ice could hold other volatiles such as organics. Unfortunately, all of this water comes in the form of ice, as surface temperatures in the poles are too cold to allow for a thaw. In addition, the total lack of atmosphere on Mercury would mean that any liquid would evaporate and be sucked into space very quickly.

At a briefing which was held yesterday, Sean Solomon – MESSENGER Principal Investigator – has this to say about the news: “These findings reveal a very important chapter of the story of how water ice has been delivered to the inner planets by comets and water rich asteroids over time.” In short, it is believed that these ice deposits and organic molecules were delivered to the planet through a series of meteor impacts, and which have survived thanks to the existence of Mercury’s permanently shadowed polar regions.

Granted, no settlers are ever likely to be making a home on Mercury – not without some serious technological innovations! – but the discovery is a very interesting find and does help scientists to understand how life may have begun here on Earth. What’s more, this news may help Curiosity and other science teams to determine where and how organic molecules and ice could be found on Mars. The challenges there are similar to those on Mars, since she too is an inner planet that has virtually no atmosphere and a great deal of surface radiation, not to mention that she too would have been the recipient of water ice and organics through meteoric impacts.

So c’mon Mars! Show us what you got. You don’t want to be outdone by your Hermian cousin do ya?