NASA-led study looks at sea ice differences at Earth’s poles 

Posted: May 23, 2016 by oldbrew in Analysis, sea ice
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Antarctic sea ice reached a record maximum extent while the Arctic reached a minimum extent in the ten lowest since satellite records began. Why are these trends going in opposite directions? Credits: NASA Goddard Space Flight Center/Joy Ng

Antarctic sea ice reached a record maximum extent while the Arctic reached a minimum extent in the ten lowest since satellite records began. Why are these trends going in opposite directions?
Credits: NASA Goddard Space Flight Center/Joy Ng


It’s hard not to suspect a politicized element to the results of such a study due to the NASA/NOAA factor. They say Antarctic sea ice has increased ‘just slightly’ since the 1970s but some might put it stronger than that.

Why has the sea ice cover surrounding Antarctica been increasing slightly, in sharp contrast to the drastic loss of sea ice occurring in the Arctic Ocean? A new NASA-led study finds the geology of Antarctica and the Southern Ocean are responsible.

A NASA/NOAA/university team led by Son Nghiem of NASA’s Jet Propulsion Laboratory, Pasadena, California, used satellite radar, sea surface temperature, land form and bathymetry (ocean depth) data to study the physical processes and properties affecting Antarctic sea ice.

They found that two persistent geological factors—the topography of Antarctica and the depth of the ocean surrounding it—are influencing winds and ocean currents, respectively, to drive the formation and evolution of Antarctica’s sea ice cover and help sustain it. “Our study provides strong evidence that the behavior of Antarctic sea ice is entirely consistent with the geophysical characteristics found in the southern polar region, which differ sharply from those present in the Arctic,” said Nghiem.

Antarctic sea ice cover is dominated by first-year (seasonal) sea ice. Each year, the sea ice reaches its maximum extent around the frozen continent in September and retreats to about 17 percent of that extent in February. Since the late 1970s, its extent has been relatively stable, increasing just slightly; however, regional differences are observed.

Over the years, scientists have floated various hypotheses to explain the behavior of Antarctic sea ice, particularly in light of observed global temperature increases. Are changes in the ozone hole involved? Could fresh meltwater from Antarctic ice shelves be making the ocean surface less salty and more conducive to ice formation, since salt inhibits freezing? Are increases in the strength of Antarctic winds causing the ice to thicken? Something is protecting Antarctic sea ice, but a definitive answer has remained elusive.

To tackle this cryospheric conundrum, Nghiem and his team adopted a novel approach. They analyzed radar data from NASA’s QuikScat satellite from 1999 to 2009 to trace the paths of Antarctic sea ice movements and map its different types. They focused on the 2008 growth season, a year of exceptional seasonal variability in Antarctic sea ice coverage.

Read the rest of the phys.org report here.
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Related: Antarctic Sea Ice Reaches New Record Maximum | NASA – Oct. 2014

Comments
  1. oldbrew says:

    A year ago: ‘Antarctic sea ice soars, as Arctic coverage diminishes’

    ‘Sea ice coverage in the Antarctic continues to increase, according to data released on Thursday by the US National Oceanic and Atmospheric Administration (NOAA).

    The ocean’s sea ice levels were 44.6% higher than the 1981-2010 average, breaking a prevous record set in 2008 by 220,000 square miles.

    The growth came in a month NOAA says was the second warmest January on record since 1880, 0.77C above the 20th century average.’
    http://www.climatechangenews.com/2015/02/19/antarctic-sea-ice-soars-as-arctic-coverage-diminishes/

    ‘Soars’ and ‘increasing slightly’ don’t have quite the same emphasis😉

    Seems to be an attempt at ‘nothing to see here, move along please.’

  2. RoswellJohn says:

    They stopped at 2009 whereas the NOAA study went to 2010. Hmmmm.

  3. erl happ says:

    The reason for the increase in Antarctic sea ice is the falling temperature of the waters in high southern latitudes over the last fifty years. That in turn is associated with increased cloud cover. The shift of atmospheric mass from high southern to the mid latitudes increases the strength and persistence of the north westerly winds taking tropical moisture to latitudes where fronts are formed with their associated clouds. The collapse in surface pressure in high southern latitudes means weaker low pressure cells on the margins of Antarctica. So the fronts form up at higher latitudes……more cloud, less sunshine at the surface.

    Associated of course with the 25% decline in winter rainfall across southern Australia. But never mind, the increase in CO2 has increased water use efficiency and the net result is about 30% more green leaves. We live in fortunate times.

    NASA hasn’t got a clue. And nor are they interested in anything that would challenge their assumptions.

  4. E.M.Smith says:

    There is a long cycle oscillation between the two poles, well attested in the data. Most likely lunar tidal driven. The NASA NOAA folks ignore all things lunar tidal driven in climate, so are always wrong on cause. It is the moon dragging big masses of water north and south over its cycles that causes polar oscillations; the sun shifting red to blue, high UV to low UV, that changes atmospheric height and % sunshine 100 m down in the ocean as uv or causing prompt surface evaporation as IR.

    Both driven by planetary gravitational stirring in orbital resonace, so both acting in concert.

  5. Paul Vaughan says:

    stating the obvious, as though it’s some brilliant revelation:

    ““Our study provides strong evidence that the behavior of Antarctic sea ice is entirely consistent with the geophysical characteristics found in the southern polar region, which differ sharply from those present in the Arctic,””

  6. oldbrew says:

    Then there’s the bi-polar seesaw.
    https://tallbloke.wordpress.com/2014/04/28/the-bi-polar-seesaw-whats-happening/

    Cynic’s summary of NASA/NOAA report:
    Antarctic sea ice increase – no problem, natural causes
    Arctic sea ice decrease – doom and gloom, man-made causes

    Comment: well they would say that, wouldn’t they?

  7. […] it’s possible to claim almost anything you want about sea ice observations. Recently NASA was ‘blaming’ the geology for the contrasting polar variations. Now it’s the IPO. H/T […]

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