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Tag Archive: sea ice

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

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    • Weather conditions and a boost from global warming led to the stunning record low ice cover in winter 2018
    • “There’s never ever been anything remotely like this for sea ice” in the Bering Sea going back more than 160 years
    • The unusual warmth continued throughout this winter, in part because of an atmospheric pattern that kept warm air and storms periodically sweeping up from the south
    • At the end of April the Bering Sea was nearly ice-free—four weeks ahead of schedule.

    By Andrea Thompson on May 2, 2018  Read full Scientific American article here

    April should be prime walrus hunting season for the native villages that dot Alaska’s remote western coast. In years past the winter sea ice where the animals rest would still be abundant, providing prime targets for subsistence hunters. But this 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.

    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….

    …The unusual warmth continued throughout this winter, in part because of an atmospheric pattern that kept warm air and storms periodically sweeping up from the south. One such event in February helped push the monthly temperature over the Bering and Chukchi seas some 18 to 21.5 degrees Fahrenheit (10 to 12 degrees Celsius) above normal. Consequently, the Bering Sea lost half its ice extent at a time when ice should still have been growing. The storms also pushed back against the normal southward flow of ice from the Chukchi Sea into the Bering. Accompanying winds stirred up waves that kept new ice from forming, and broke up what thin ice there was….

    …“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 again.

  2. How openings- polynyas- in Antarctic sea ice affect worldwide climate

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    • Heat escaping from the ocean through openings in sea ice impact sea and atmospheric temperatures and wind patterns around the globe and even rainfall around the tropics.

    September 11, 2017 University of Pennsylvania Read full ScienceDaily article here

    In a new analysis of climate models, researchers reveal the significant global effects that seemingly anomalous polynyas, or openings in sea ice, can have. Their findings indicate that heat escaping from the ocean through these openings impacts sea and atmospheric temperatures and wind patterns around the globe and even rainfall around the tropics.…Though this process is part of a natural pattern of climate variability, it has implications for how the global climate will respond to future anthropogenic warming.

    …The work raises many new questions, such as how a decreasing sea ice extent, including the recent breaking off of a massive chunk of the Antarctic peninsula, will affect the frequency of polynyas and how the presence or absence of polynyas will affect how much atmospheric temperatures warm in response to anthropogenic climate change.

    ….Their model indicated that polynyas and accompanying open-ocean convection occur roughly every 75 years. When they occur, the researchers observed, they act as a release valve for the ocean’s heat. Not only does the immediate area warm, but there are also increases in overall sea-surface and atmospheric temperatures of the entire Southern Hemisphere and, to a lesser extent, the Northern Hemisphere, as well….

    Anna Cabré, Irina Marinov, Anand Gnanadesikan. Global Atmospheric Teleconnections and Multidecadal Climate Oscillations Driven by Southern Ocean Convection. Journal of Climate, 2017; 30 (20): 8107 DOI: 10.1175/JCLI-D-16-0741.1

  3. Arctic Heat Is Becoming More Common and Persistent

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    By July 13 2017  see full Climate Central article here the latest sign of how quickly changes are happening, new research published this week shows that the Arctic has seen more frequent bouts of warm air and longer stretches of mild weather.  The new findings show that while warm snaps have occurred even as far as back as the 1890s, a massive shift is afoot in the region, which is warming twice as fast as the rest of the world

    Background temperatures have also been rising faster there. The North Pole region has warmed 2.3°F (1.3°C) per decade since 1979, a trend largely driven by climate change. Though the new study doesn’t tease out whether the increase in warm days is due directly to climate change, it’s part of a huge pile of evidence of how rising carbon pollution is altering the Arctic faster than the rest of the world….

    From ScienceDaily article:

    ….The winter of 2015-2016, for example, saw temperatures nearly 3.6 degrees Fahrenheit (2 degrees Celsius) warmer than the previous record high monthly winter temperature. At the end of December 2015, scientists recorded a temperature of 36 degrees Fahrenheit (2.2 degrees Celsius) in the Central Arctic, the warmest temperature ever recorded in this region from December through March.

    …On average, the Atlantic side of the North Pole now has ten warming events each winter, while the Pacific Central Arctic has five such events, according to the study. More storms come in to the Arctic from the Atlantic Ocean during winter, which results in more warming events on the Atlantic side of the North Pole….

    Robert M. Graham, Lana Cohen, Alek A. Petty, Linette N. Boisvert, Annette Rinke, Stephen R. Hudson, Marcel Nicolaus, Mats A. Granskog. Increasing frequency and duration of Arctic winter warming events. Geophysical Research Letters, 2017; DOI: 10.1002/2017GL073395

  4. Arctic Sea Ice– April 2017 tied April 2016 for lowest extent on record

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    Arctic Sea Ice Keeps Scraping the Bottom of the Barrel: Ice older than five years in age now only comprises 5 percent of the Arctic’s ice pack compared to 30% in 1984

    This April merely tied April 2016 for the lowest extent on record, but it’s hardly reason to celebrate. The Arctic was missing 394,000 square miles of ice, with each day setting a record low or within 36,000 square miles of setting one…

    ….One of the biggest issues for sea ice is its increasingly youthful appearance. Young ice is more susceptible to the vagaries of weather, whether it be warm air or water or storms that knock it around and break it up.

    Ice older than five years in age now only comprises 5 percent of the Arctic’s ice pack. It accounted for 30 percent of all Arctic sea ice in 1984, but relentless warmth driven by rising carbon dioxide in the atmosphere has slowly squeezed it out of existence….

    Arctic sea ice extent has trended in record low territory for months.Credit: Zack Labe

  5. Climate change increasingly responsible for record-setting extreme weather events

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    April 25 2017 Stanford University see full ScienceDaily article here

    In the past, scientists typically avoided linking individual weather events to climate change, citing the challenges of teasing apart human influence from the natural variability of the weather. But that is changing.

    …In a new study, published in this week’s issue of Proceedings of the National Academy of Sciences, Diffenbaugh and a group of current and former Stanford colleagues outline a four-step “framework” for testing whether global warming has contributed to record-setting weather events. The new paper is the latest in a burgeoning field of climate science called “extreme event attribution,” which combines statistical analyses of climate observations with increasingly powerful computer models to study the influence of climate change on individual extreme weather

    ….”Our results suggest that the world isn’t quite at the point where every record hot event has a detectable human fingerprint, but we are getting close,” Diffenbaugh said. For the driest and wettest events, the authors found that human influence on the atmosphere has increased the odds across approximately half of the area that has reliable observations.

    ….One high-profile test case was Arctic sea ice, which has declined by around 40 percent during the summer season over the past three decades. When the team members applied their framework to the record-low Arctic sea ice cover observed in September 2012, they found overwhelming statistical evidence that global warming contributed to the severity and probability of the 2012 sea ice measurements. “The trend in the Arctic has been really steep, and our results show that it would have been extremely unlikely to achieve the record-low sea ice extent without global warming,” Diffenbaugh said.

    Noah S. Diffenbaugh, Deepti Singh, Justin S. Mankin, Daniel E. Horton, Daniel L. Swain, Danielle Touma, Allison Charland, Yunjie Liu, Matz Haugen, Michael Tsiang, Bala Rajaratnam. Quantifying the influence of global warming on unprecedented extreme climate events. Proceedings of the National Academy of Sciences, 2017; 201618082 DOI: 10.1073/pnas.1618082114


  6. Sea ice extent sinks to record lows at both poles

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    Posted: 22 Mar 2017 11:31 AM PDT see full ScienceDaily article here

    The Arctic sea ice maximum extent and Antarctic minimum extent are both record lows this year. Combined, sea ice numbers are at their lowest point since satellites began to continuously measure sea ice in 1979.…”There’s a lot of year-to-year variability in both Arctic and Antarctic sea ice, but overall, until last year, the trends in the Antarctic for every single month were toward more sea ice,” said Claire Parkinson, a senior sea ice researcher at Goddard. “Last year was stunningly different, with prominent sea ice decreases in the Antarctic. To think that now the Antarctic sea ice extent is actually reaching a record minimum, that’s definitely of interest

    Arctic sea ice hit a record low wintertime maximum extent in 2017. At 5.57 million square miles, it is the lowest maximum extent in the satellite record, and 455,600 square miles below the 1981 to 2010 average maximum extent.
    Credit: NASA Goddard’s Scientific Visualization Studio/L. Perkins


  7. Climate breaks multiple records in 2016, with global impacts

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    March 21 2017

    The year 2016 made history, with a record global temperature, exceptionally low sea ice, and unabated sea level rise and ocean heat, according to the World Meteorological Organization (WMO). Extreme weather and climate conditions have continued into 2017.

    WMO issued its annual statement on the State of the Global Climate ahead of World Meteorological Day on 23 March. It is based on multiple international datasets maintained independently by global climate analysis centres and information submitted by dozens of WMO Members National Meteorological and Hydrological Services and Research Institutes and is an authoritative source of reference. Because the social and economic impacts of climate change have become so important, WMO partnered with other United Nations organizations for the first time this year to include information on these impacts. WMO also prepared an interactive story map to highlight some of the main trends and events in 2016.

    This report confirms that the year 2016 was the warmest on record – a remarkable 1.1 °C above the pre-industrial period, which is 0.06 °C above the previous record set in 2015. This increase in global temperature is consistent with other changes occurring in the climate system,” said WMO Secretary-General Petteri Taalas….

  8. Near-Record Low 2016 Arctic Sea Ice

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    2016 ties with 2007 for second lowest Arctic sea ice minimum

    By Brian Kahn September 15th, 2016

    Arctic sea ice is one of the grandaddy’s of climate indicators. …. This year’s sea ice extent has bottomed out as the second lowest on record, according to the National Snow and Ice Data Center. It continues a troubling trend as rapidly warming air and water eats away at the briny, frozen mantle on the top of the planet…. This year has been exceptional by many standards. March saw the lowest sea ice maximum ever recorded followed by a string of record low months. The Northwest Passage opened up, allowing a luxury cruise ship to travel from Anchorage to New York. And a freak storm in August turned ice thin and brittle near the North Pole. Satellites show the last seven months of sea ice and reveal its steep decline this year. The late August breakup is particularly notable.

    All 10 of the smallest sea ice extents on record have occurred since 2005. In the nearly four decades of satellite monitoring, sea ice has disappeared at a clip of 13.4 percent per decade. This year’s cracked ice also continues a troubling trend of disappearing old ice. Though some of that ice will refreeze together this winter, some has disappeared for good and new ice will be left to fill in the gaps. That’s like putting a piece of paper over a hole in your wall, though. Young ice tends to be weaker and thinner and thus more susceptible to summer melt. It’s a trend that’s already happening. Ice younger than four years comprised 97 percent of all Arctic sea ice in 2015 compared to 80 percent in 1985….

    2016 ties with 2007 for second lowest Arctic sea ice minimum

    Posted: 15 Sep 2016 12:33 PM PDT

    The Arctic’s ice cover appears to have reached its minimum extent on September 10, 2016, according to scientists. Arctic sea ice extent on that day stood at 4.14 million square kilometers (1.60 million square miles), statistically tied at second lowest in the satellite record with the 2007 minimum.

  9. Historical documents reveal Arctic sea ice is disappearing at record speed

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    Posted on 22 August 2016 by dana1981

    Walsh, J. E., Fetterer, F., Stewart, J. S. and Chapman, W. L. (2016) A database for depicting Arctic sea ice variations back to 1850. Geographical Review, doi:10.1111/j.1931-0846.2016.12195.x

    Scientists have pieced together historical records to reconstruct Arctic sea ice extent over the past 125 years. The results are shown in the figure below. The red line, showing the extent at the end of the summer melt season, is the most critical:

    Arctic sea ice extent in recent years is by far the lowest it’s been, with about half of the historical coverage gone, and the decline the fastest it’s been in recorded history. Florence Fetterer, principal investigator at the National Snow and Ice Data Center, described the data reconstruction process in a guest post at Carbon Brief….

    ….Most fundamentally of all, the new dataset allows us to answer the three questions we posed at the beginning of this article.

    First, there is no point in the past 150 years where sea ice extent is as small as it has been in recent years. Second, the rate of sea ice retreat in recent years is also unprecedented in the historical record. And, third, the natural fluctuations in sea ice over multiple decades are generally smaller than the year-to-year variability.