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...
‘We’ve fallen off a cliff’: Scientists have never seen so little ice in the Bering Sea in spring

‘We’ve fallen off a cliff’: Scientists have never seen so little ice in the Bering Sea in spring

SOURCE: Seattle Times DATE: May 3, 2018 SNIP: In the middle of February, one-third of the ice covering the Bering Sea off Alaska’s West Coast vanished within a week when an enormous pulse of heat swept over the Arctic. Scientists were stunned. This rapid meltdown precipitated a record-shattering decline in Bering Sea ice through the winter and into spring, which has threatened the very way of life in Alaska’s coastal villages — reliant on the ice cover for navigation and hunting. February and March ice levels were as low as far back as scientists can reconstruct, dating back more than 160 years. Now, the ice is almost entirely gone — just 10 percent of normal levels as of the end of April. “We’ve fallen off a cliff: very little sea ice remains in the Bering Sea,” tweeted Rick Thoman, an Alaska-based climatologist with the National Oceanic and Atmospheric Administration, on April 29. The ice extent over the Chukchi Sea, just north of the Bering Sea abutting Alaska’s northwest coast, is also abnormally depleted. It recently began its melt season earlier than ever before...
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...
Record levels of plastic discovered in Arctic sea ice

Record levels of plastic discovered in Arctic sea ice

SOURCE: The Guardian DATE: April 24, 2018 SNIP: Scientists have found a record amount of plastic trapped in Arctic sea ice, raising concern about the impact on marine life and human health. Up to 12,000 pieces of microplastic particles were found per litre of sea ice in core samples taken from five regions on trips to the Arctic Ocean – as many as three times higher than levels in previous studies. Researchers at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) found fragments of packaging, paints, nylon, polyester and cellulose acetate which is commonly used in making cigarette filters in every sample they took in 2014 and 2015. The findings come amid growing concern about the scale of plastic pollution which experts have warned risks the near-permanent contamination of the planet. “Microplastic particles were found throughout all cores sampled … It suggests that microplastics are now ubiquitous within the surface waters of the world’s ocean. Nowhere is...
What Is Eating Away at the Greenland Ice Sheet?

What Is Eating Away at the Greenland Ice Sheet?

SOURCE: Inside Climate News DATE: April 19, 2018 SNIP: [T]emperatures are rising in the Arctic at about twice the global average. That causes melting around the edges of the ice sheet each year and reaches across more of the surface during summer heat waves. In areas near the edge of the ice sheet, things get even more interesting: a carpet of microbes and algae mixed with dust and soot, a short-lived climate pollutant, is darkening the ice sheet, absorbing the sun’s rays and accelerating the melting of the ice. New research shows this dark zone is growing. The new research, published in the journal Nature Communications, describes a geological feedback loop on the ice that’s expanding the dark zone: Warming melts the western edge of the ice sheet, releasing mineral dust from rock crushed by the ice sheet thousands of years ago. That dust blows to the surface of the ice, nurturing the microbes and algae living there. Those organisms produce colored pigments as sunscreen, which contribute to the darkening of the surface, reducing reflectivity and increasing melting. “Just the little bit of extra heat from a tiny soot particle can start transforming feathery and highly reflective snow crystals into darker, rounded grains that absorb more heat,” said climate researcher Jason...