Religion and Ethics Forum
General Category => General Discussion => Topic started by: Sriram on November 19, 2016, 09:50:02 AM
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Hi everyone,
After all the fear and anger over brexit and Trump, here is something to be really afraid of.
https://www.washingtonpost.com/news/energy-environment/wp/2016/11/17/the-north-pole-is-an-insane-36-degrees-warmer-than-normal-as-winter-descends/?utm_term=.21fe53fdcdbe
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Political people in the United States are watching the chaos in Washington in the moment. But some people in the science community are watching the chaos somewhere else — the Arctic.
It’s polar night there now — the sun isn’t rising in much of the Arctic. That’s when the Arctic is supposed to get super-cold, when the sea ice that covers the vast Arctic Ocean is supposed to grow and thicken.
But in fall of 2016 — which has been a zany year for the region, with multiple records set for low levels of monthly sea ice — something is totally off. The Arctic is super-hot, even as a vast area of cold polar air has been displaced over Siberia.
Twitter’s expert Arctic watchers also are stunned. Zack Labe, a PhD student at the University of California at Irvine who studies the Arctic, tweeted out an image on Wednesday from the Danish Meteorological Institute showing Arctic temperatures about 20 degrees Celsius higher than normal above 80 degrees North Latitude.
“Today’s latest #Arctic mean temperature continues to move the wrong direction . . . up. Quite an anomalous spike!,” Labe wrote.
“It’s about 20C [36 degrees Fahrenheit] warmer than normal over most of the Arctic Ocean, along with cold anomalies of about the same magnitude over north-central Asia,” Jennifer Francis, an Arctic specialist at Rutgers University, said
Since November, temperatures have risen even higher. “It is amazing to see that the warmth has become even more pronounced since the end of October,”
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Cheers.
Sriram
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Thanks for your post.
What if the temperature went 25 degrees above in a populated country? That would as they say, be it.
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Hi everyone,
After all the fear and anger over brexit and Trump, here is something to be really afraid of.
https://www.washingtonpost.com/news/energy-environment/wp/2016/11/17/the-north-pole-is-an-insane-36-degrees-warmer-than-normal-as-winter-descends/?utm_term=.21fe53fdcdbe
***********
Political people in the United States are watching the chaos in Washington in the moment. But some people in the science community are watching the chaos somewhere else — the Arctic.
It’s polar night there now — the sun isn’t rising in much of the Arctic. That’s when the Arctic is supposed to get super-cold, when the sea ice that covers the vast Arctic Ocean is supposed to grow and thicken.
But in fall of 2016 — which has been a zany year for the region, with multiple records set for low levels of monthly sea ice — something is totally off. The Arctic is super-hot, even as a vast area of cold polar air has been displaced over Siberia.
Twitter’s expert Arctic watchers also are stunned. Zack Labe, a PhD student at the University of California at Irvine who studies the Arctic, tweeted out an image on Wednesday from the Danish Meteorological Institute showing Arctic temperatures about 20 degrees Celsius higher than normal above 80 degrees North Latitude.
“Today’s latest #Arctic mean temperature continues to move the wrong direction . . . up. Quite an anomalous spike!,” Labe wrote.
“It’s about 20C [36 degrees Fahrenheit] warmer than normal over most of the Arctic Ocean, along with cold anomalies of about the same magnitude over north-central Asia,” Jennifer Francis, an Arctic specialist at Rutgers University, said
Since November, temperatures have risen even higher. “It is amazing to see that the warmth has become even more pronounced since the end of October,”
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Cheers.
Sriram
Trump doesn't believe in global warming! :o
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A 20 degree C difference in average temp is bad enough in the Arctic. If that sort of thing continues, the ice will melt and the sea levels could rise dramatically much sooner than is predicted.
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A 20 degree C difference in average temp is bad enough in the Arctic. If that sort of thing continues, the ice will melt and the sea levels could rise dramatically much sooner than is predicted.
if the sea ice in the arctic melted there would be no change to sea levels
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if the sea ice in the arctic melted there would be no change to sea levels
True, though Sriram's phrasing might include all the ice not just Arctic ice. Also an overall increase in water temperatures would lead to rising sea levels.
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True, though Sriram's phrasing might include all the ice not just Arctic ice. Also an overall increase in water temperatures would lead to rising sea levels.
do you know the volume expansion of sea water per degree C as a percentage(off hand)?
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Are we talking about a 20 degree rise in expected temperature only occurring in late autumn winter over polar regions...or can this happen anywhere in any season?
If the latter, sea level rise would be the least of our problems.
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do you know the volume expansion of sea water per degree C as a percentage(off hand)?
no, sorry.
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no, sorry.
thanks
I will have to look it up.
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I think one of the associated problems is the release of methane, which is a strong greenhouse gas, from seas and soils in permafrost regions of the Arctic, due to de-glaciation.
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The really cold weather has been quite late this year - it's only in the last week have we seen any frosty weather here.
Nick
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Look on the bright side, at this rate Northern Antarctica will be suitable for crop growing by the turn of the century :).
And this belongs on the Science Board.
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if the sea ice in the arctic melted there would be no change to sea levels
The real problem would be that the water is warmer and would therefore expand.
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Trump doesn't believe in global warming! :o
Sorry, Floo. He does believe it exists - just that it isn't man-made.
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Looks as if the mix between political events and science has been ramped up by recent events.
http://www.bbc.co.uk/news/science-environment-38034171
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do you know the volume expansion of sea water per degree C as a percentage(off hand)?
http://chemistry.stackexchange.com/questions/15599/how-much-does-water-expand-when-heated-and-does-salt-affect-that
Apparently the equation for the calculation is
ΔV=Vo β ΔT
where β is the coefficient of thermal expansion and ΔT is the change in temperature in degrees K.
β for pure water at 25oC = 257⋅10-6/oK
β for water with 35% NaCl dissolved at 25o C = 297⋅10−6/oK
Hope this has transferred OK
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http://chemistry.stackexchange.com/questions/15599/how-much-does-water-expand-when-heated-and-does-salt-affect-that
Apparently the equation for the calculation is
ΔV=Vo β ΔT
where β is the coefficient of thermal expansion and ΔT is the change in temperature in degrees K.
Hope this has transferred OK
it has
but I'm going to have to get my bag of beans out to do the sums.
looking at the coefficient value it appears the expansion is very small
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it has
but I'm going to have to get my bag of beans out to do the sums.
looking at the coefficient value it appears the expansion is very small
The 'very small' can equate to a considerable amount when one takes the total volume of water on the earth into account.
The total volume of water on Earth is estimated at 1.386 billion km³ (333 million cubic miles), with 97.5% being salt water and 2.5% being fresh water. Of the fresh water, only 0.3% is in liquid form on the surface. In addition, the lower mantle of inner earth may hold as much as 5 times more water than all surface water combined (all oceans, all lakes, all rivers)
https://en.wikipedia.org/wiki/Water_distribution_on_Earth
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it has
but I'm going to have to get my bag of beans out to do the sums.
looking at the coefficient value it appears the expansion is very small
So if you have a billion cubic kilometres and it's at 25C and it's fresh water and it's temperature goes up to 26C, you'll end up with an extra 257,000 cubic kilometres. The Earth is 510 million square kilometres in surface area, so for each square kilometre there is an extra 0.0005 cubic kilometres of water which doesn't seem much until you realise that, spread evenly over the square kilometre and hence the whole Earth, it would be 50 cm deep.
It's actually more complicated than that because the coefficient varies with temperature, pressure and salinity, all of which vary in the oceans.
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So if you have a billion cubic kilometres and it's at 25C and it's fresh water and it's temperature goes up to 26C, you'll end up with an extra 257,000 cubic kilometres. The Earth is 510 million square kilometres in surface area, so for each square kilometre there is an extra 0.0005 cubic kilometres of water which doesn't seem much until you realise that, spread evenly over the square kilometre and hence the whole Earth, it would be 50 cm deep.
It's actually more complicated than that because the coefficient varies with temperature, pressure and salinity, all of which vary in the oceans.
excellent work jp
did you use actual figures regarding initial volumes? or was it to show the example
and as you say there are variables to consider
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excellent work jp
did you use actual figures regarding initial volumes? or was it to show the example
and as you say there are variables to consider
I rounded the 1.3 billion km3 of water quoted by Hope to a billion to make the maths easier. Everything else uses the figures quoted by Hope. The idea is only to get a handle on the order of magnitude because there's actually more water than I said (which makes the change deeper), not all the Earth is covered in water (which makes it even deeper), the coefficient goes up with pressure (deeper again) and down with temperature (shallower because the ocean is colder than 25C).
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I rounded the 1.3 billion km3 of water quoted by Hope to a billion to make the maths easier. Everything else uses the figures quoted by Hope. The idea is only to get a handle on the order of magnitude because there's actually more water than I said (which makes the change deeper), not all the Earth is covered in water (which makes it even deeper), the coefficient goes up with pressure (deeper again) and down with temperature (shallower because the ocean is colder than 25C).
thanks , great stuff ill put my bag of beans back in the drawer
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http://www.ndtv.com/world-news/norwegian-archipelago-sees-shocking-temperatures-near-freezing-point-1630339?pfrom=home-lateststories
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The Arctic archipelago of Svalbard has seen such extreme warmth this year that the average annual temperature could end up above freezing for the first time on record, scientists said Friday.
Ketil Isaksen of the Norwegian Meterological Institute said that the average temperature in Longyearbyen, the main settlement in Svalbard, is expected to be around zero degree celsius with a little over a month left of the year.
"This is a little bit shocking," Mr Isaksen said. "If you had asked me five or 10 years ago, I could not have imagined such numbers in 2016."
The normal yearly average in Svalbard, an island group midway between the North Pole and continental Norway, is minus 6.7 degrees celsius and the warmest year until now was 2006, when the average temperature in Svalbard was minus 1.8 degrees celsius, Mr Isaksen said.
"Svalbard is a very good spot to show what's happening in the Arctic at the moment," he said, noting that each of the past 73 months has been warmer than average.
The rising temperatures in the Arctic are affecting permafrost and snow cover as well as the amount of sea ice, which this year was the second-lowest on record.
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