Gravity data reveal unexpected Antarctic ice variations 

Posted: December 7, 2020 by oldbrew in data, Gravity, Natural Variation, research, sea levels, Uncertainty, weather
Tags:

Antarctica


If they were hoping to see a steady rate of change that matched carbon dioxide emission levels, they were disappointed. Natural variations inconveniently got in the way, two in particular: ‘When two extreme snowfall events in 2009 and 2011 dropped around 600 gigatons of snow and ice, the East Antarctic Ice Sheet thickened so much that it temporarily halted the entire continent’s ice losses, said Wang—a pattern that had previously escaped notice.’
– – –
A new analysis of long-term satellite records shows the East Antarctic Ice Sheet is unexpectedly dependent on fluctuations in weather.

This study may improve models of how much sea levels will rise, says Eos News.

As more coastal communities face the looming threat [Talkshop note: unsupported assertion] of rising sea levels, it’s more important than ever to accurately predict changes in one of the greatest potential sources of sea level rise—the melting of Antarctica’s massive ice sheet.

Recently, scientists analyzed nearly 2 decades’ worth of data from sensitive NASA satellites documenting mass changes in the Antarctic Ice Sheet.

They found the ice inventory ebbed and flowed across the continent in unexpectedly variable patterns.

Traditionally, some groups of Antarctic researchers have assumed the rate of change across the ice sheet is constant, but they drew their conclusions from data sets that spanned only a few years, said Lei Wang, a geodesist at The Ohio State University who will present this research at AGU’s virtual Fall Meeting 2020.

“These long data records give us the capability to characterize the ice sheet’s variation over a range of timescales,” rather than just modeling seasonal variations and short-term trends, Wang said.

Understanding Long-Term Trends

The Antarctic Ice Sheet, the largest mass of ice on Earth, is divided into two unequal portions, with the East Antarctic Ice Sheet covering about two thirds of the continent. The West Antarctic Ice Sheet, although smaller, has historically been more closely studied because it’s melting faster. (The East Antarctic Ice Sheet sits on bedrock above sea level, said Wang, so it is less susceptible to the effects of the warming ocean.) NASA estimates Antarctica has lost 149 billion metric tons of ice per year since 2002.

When so much ice is involved, projections of how sea levels will respond are uncertain—especially when trends already are so difficult to gauge.

Indeed, the field still argues about sea level changes in the past century, said Jim Davis, the study coauthor and a geodesist at the Lamont-Doherty Earth Observatory at Columbia University. “We’ve got to get to the point where we can talk about what’s happening this year in sea level change,” he said.

To do that, researchers need a more sophisticated model of how Antarctica’s shield of ice is evolving.

Full article here.

Comments
  1. oldbrew says:

    Unnoticed at the time: ‘When two extreme snowfall events in 2009 and 2011 dropped around 600 gigatons of snow and ice…’

    While the climate cult was busy wringing its hands about some melting icebergs in the Arctic 🙄

    ‘Researchers need a more sophisticated model’
    Of course – they always do.

  2. Curious George says:

    “We’ve got to get to the point where we can talk about what’s happening this year in sea level change.” Don’t be too modest. Tell us what’s happening in the sea level change today.

  3. oldbrew says:

    ‘the ice inventory ebbed and flowed’
    ‘trends already are so difficult to gauge’

    But ‘NASA estimates Antarctica has lost 149 billion metric tons of ice per year since 2002’ ?

    If they have 40 years of data, what was happening prior to 2002?

  4. tom0mason says:

    “The Antarctic Ice Sheet, the largest mass of ice on Earth, is divided into two unequal portions, with the East Antarctic Ice Sheet covering about two thirds of the continent. The West Antarctic Ice Sheet, although smaller, has historically been more closely studied because it’s melting faster. (The East Antarctic Ice Sheet sits on bedrock above sea level, said Wang, so it is less susceptible to the effects of the warming ocean.) NASA estimates Antarctica has lost 149 billion metric tons of ice per year since 2002.”

    Yes lets not look at the Antarctic ice sheet holistically, let just arbitrarily split it up so that we can write more alarmist sophistry about the guesswork NASA claims about ice loss.
    Hey NASA how much ice has the Eastern side of the Antarctic gained?
    Hey researchers why do you all willfully ignore all the volcanic activity on and under the western Antarctic region? — STOP the BS and start some real research you bloody wastrels!

  5. Kip Hansen says:

    Many coastal communities are already at risk from sea levels — rising or not — Miami Beach, with a major intersection that is already below mean high tide and was below high water when it was built! Whole neighborhoods on the Miami mainland are built on canals with 1 single foot of freeboard…these neighborhoods flood every time there is storm surge. ref: https://wattsupwiththat.com/2016/12/07/miamis-vice/

  6. Phoenix44 says:

    Honestly this is science at the level of leeches in medicine. If they didn’t have a model to feed guesses into it would nothing whatsoever.

  7. oldbrew says:

    the East Antarctic Ice Sheet is unexpectedly dependent on fluctuations in weather.

    Why ‘unexpectedly’? Snow is weather, but climate modellers can’t seem to grasp that.
    = = =
    NORTH POLE MELTING. CHANGE OF CLIMATE. MANY GLACIERS VANISHED.
    Northern Star (Lismore, NSW : 1876 – 1954) Thursday 5 April 1923

    https://tallbloke.wordpress.com/2013/04/12/is-the-north-pole-going-to-melt-entirely-asks-newspaper-in-1923/

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