Arctic’s strongest sea ice breaks up for first time on record

Arctic’s strongest sea ice breaks up for first time on record

SOURCE: The Guardian DATE: August 21, 2018 SNIP: The oldest and thickest sea ice in the Arctic has started to break up, opening waters north of Greenland that are normally frozen, even in summer. This phenomenon – which has never been recorded before – has occurred twice this year due to warm winds and a climate-change driven heatwave in the northern hemisphere. One meteorologist described the loss of ice as “scary”. Others said it could force scientists to revise their theories about which part of the Arctic will withstand warming the longest. The sea off the north coast of Greenland is normally so frozen that it was referred to, until recently, as “the last ice area” because it was assumed that this would be the final northern holdout against the melting effects of a hotter planet. But abnormal temperature spikes in February and earlier this month have left it vulnerable to winds, which have pushed the ice further away from the coast than at any time since satellite records began in the 1970s. Freakish Arctic temperatures have alarmed climate scientists since the beginning of the year. During the sunless winter, a heatwave raised concerns that the polar vortex may be eroding. This includes the Gulf Stream, which is at its weakest level in 1,600 years due to melting Greenland ice and ocean warming. With lower circulation of water and air, weather systems tend to linger...
Barents Sea seems to have crossed a climate tipping point

Barents Sea seems to have crossed a climate tipping point

SOURCE: Ars Technica DATE: June 26, 2018 SNIP: Many of the threats we know are associated with climate change are slow moving. Gradually rising seas, a steady uptick in extreme weather events, and more all mean that change will come gradually to much of the globe. But we also recognize that there can be tipping points, where certain aspects of our climate system shift suddenly to new behaviors. The challenge with tipping points is that they’re often easiest to identify in retrospect. We have some indications that our climate has experienced them in the past, but reconstructing how quickly a system tipped over or the forces that drove the change can be difficult. Now, a team of Norwegian scientists is suggesting it has watched the climate reach a tipping point: the loss of Arctic sea ice has flipped the Barents Sea from acting as a buffer between the Atlantic and Arctic oceans to something closer to an arm of the Atlantic. The Norwegian work doesn’t rely on any new breakthrough in technology. Instead, it’s built on the longterm collection of data. The Barents Sea has been monitored for things like temperature, ice cover, and salinity, in some cases extending back over 50 years. This provides a good baseline to pick up longterm changes. And, in the case of the Barents Sea in particular, it’s meant we’ve happened to have been watching as a major change took place. [N]ot only have we discovered a climate tipping point, but we’ve spotted it after the system has probably already flipped into a new regime. It also provides some sense of what to...
In the Arctic, the Old Ice Is Disappearing

In the Arctic, the Old Ice Is Disappearing

SOURCE: New York Times DATE: May 14, 2018 SNIP: In the Arctic Ocean, some ice stays frozen year-round, lasting for many years before melting. But this winter, the region hit a record low for ice older than five years. This, along with a near-record low for sea ice over all, supports predictions that by midcentury there will be no more ice in the Arctic Ocean in summer. As darker, heat-absorbing water replaces reflective ice, it hastens warming in the region. Older ice is generally thicker than newer ice and thus more resilient to heat. But as the old ice disappears, the newer ice left behind is more vulnerable to rising temperatures. “First-year ice grows through winter and then to up to a maximum, which is usually around in March,” said Mark A. Tschudi, a research associate at the Colorado Center for Astrodynamics Research at the University of Colorado, Boulder. “As summer onsets, the ice starts to melt back.” Some of the new ice melts each summer, but some of it lingers to grow thicker over the following winter, forming second-year ice. The next summer, some of that second-year ice survives, then grows even thicker and more resilient the next winter, creating what is known as multiyear ice. Some ice used to last more than a decade. Today, Arctic sea ice is mostly first-year ice. While the oldest ice has always melted when currents pushed it south into warmer waters, now more of the multiyear ice is melting within the Arctic Ocean, leaving more open water in its wake. “I’ve been on record saying that it may be 2030 that...
Alien Waters: Neighboring Seas Are Flowing into a Warming Arctic Ocean

Alien Waters: Neighboring Seas Are Flowing into a Warming Arctic Ocean

SOURCE: Yale e360 DATE: May 10, 2018 SNIP: As the Arctic heats up faster than any other region on the planet, once-distinct boundaries between the frigid polar ocean and its warmer, neighboring oceans are beginning to blur, opening the gates to southern waters bearing foreign species, from phytoplankton to whales. The “Atlantification” and “Pacification” of the Arctic Ocean are now rapidly advancing. A new paper by University of Washington oceanographer Rebecca Woodgate, for example, finds that the volume of Pacific Ocean water flowing north into the Arctic Ocean through the Bering Strait surged up to 70 percent over the past decade and now equals 50 times the annual flow of the Mississippi River. And over on the Atlantic flank of the Arctic, another recent report concludes that the Arctic Ocean’s cold layering system that blocks Atlantic inflows is breaking down, allowing a deluge of warmer, denser water to flood into the Arctic Basin. “You have all this warm Pacific water coming into the Arctic and what is that going to mean?” says Robert Pickart, a physical oceanographer with the Woods Hole Oceanographic Institution in Massachusetts who studies Pacific Arctic circulation. “Not only is there more water going through, but there’s an increase in the amount of heat going through.” Adding more heat, he says, is “going to change the composition of the water and its likelihood to melt sea ice.” In addition, waters from the Atlantic that have long entered the Arctic Ocean and circled down deep are being driven higher onto shallow sea shelves north of Alaska by increasingly intense storms. (The Arctic’s extensive sea ice cover used...
Shock and Thaw—Alaskan Sea Ice Just Took a Steep, Unprecedented Dive

Shock and Thaw—Alaskan Sea Ice Just Took a Steep, Unprecedented Dive

SOURCE: Scientific American DATE: May 2, 2018 SNIP: Winter sea ice cover in the Bering Sea did not just hit a record low in 2018; it was half that of the previous lowest winter on record (2001), says John Walsh, chief scientist of the International Arctic Research Center at the University of Alaska Fairbanks. “There’s never ever been anything remotely like this for sea ice” in the Bering Sea going back more than 160 years, says Rick Thoman, an Alaska-based climatologist with the National Oceanic and Atmospheric Administration. [T]his year sea-ice coverage as of late April was more like what would be expected for mid-June, well into the melt season. These conditions are the continuation of a winter-long scarcity of sea ice in the Bering Sea—a decline so stark it has stunned researchers who have spent years watching Arctic sea ice dwindle due to climate change. The occurrence of these unusual conditions off Alaska this past winter can largely be chalked up to the random weather variations in a chaotic climate system, Bond, Walsh and Thoman all say—but they add that global warming likely amped up the severity of the situation. Because of the role the weather plays, though, “every year is not going to be like this,” Thoman says. “Next year will almost certainly not be this low.” But as temperatures continue to rise, he says, “odds are very strong that we will not go another 160 years before we see something like this” happen...