next message in archive
next message in thread
previous message in archive
Index of Subjects
--Boundary_(ID_EXJDfupp1rqX3R7g2sk/mA) Content-type: text/plain; charset=WINDOWS-1252; delsp=yes; format=flowed Content-transfer-encoding: quoted-printable For those interested, note how much of this article was left out of =20 the printed newspaper, at least for the Valley edition, versus what =20 was on the Herald Web site. Cheers from Jim in Wolfville ----------------------------- Chronicle Herald, Tuesday, June 28, 2011 http://thechronicleherald.ca/Canada/1250711.html Walkers help solve mystery of fast melt By BOB WEBER The Canadian Press Tue, Jun 28 - 4:54 AM A 500-kilometre walk over treacherous Arctic terrain has resulted in =20 a possible explanation for why sea ice in northern waters is melting =20 so much more rapidly than anyone thought it would. "We=92re trying to understand why the ice is melting so fast," said =20 Simon Boxall of the Catlin Arctic Survey. "It=92s not just down to =20 simple warming. There are more complicated processes." The speed at which sea ice is disappearing in the Arctic has far =20 exceeded almost all predictions and alarmed climate scientists. A 2007 paper from the National Snow and Ice Data Center in Boulder, =20 Colo., found that the projections of the UN-sponsored =20 Intergovernmental Panel on Climate Change were already obsolete three =20= years after they were published. When projections from the panel were compared with actual =20 observations, the authors found that between 1953 and 2006 the sea =20 ice was retreating three times faster than it should have. Between =20 1979 and 2006, when satellite data was available, the actual retreat =20 was twice as fast as climate models predicted. The report concluded that sea ice retreat is 30 years ahead of where =20 scientists thought it would be. "Decay of the ice cover is proceeding more rapidly than expected =20 based on the model simulations," said the report published in =20 Geophysical Research Letters. The team at the Catlin Arctic Survey, sponsored by the Catlin Group =20 insurance company, thought the answer might lie in different =20 temperatures at different levels of Arctic seas. Such data is usually obtained from ships. But during the spring, when =20= melting is greatest, there=92s still too much sea ice for ships to make =20= it through. So the scientists walked from Borden Island to Ellef Ringnes Island =20 and also from near the North Pole all the way down to the northern =20 tip of Ellesmere Island, slogging about 10 kilometres a day in below-=20 deep-freeze temperatures over rugged, uneven ice. What they found was a surprise =97 a layer of seawater about 200 metres =20= below the surface that was actually colder than when it had been =20 measured by previous expeditions. "That=92s counterintuitive," said Boxall. "We would expect to see, with =20= global warming, warming conditions generally." But when they realized that the colder water was also saltier than =20 they expected, an explanation began to suggest itself. Boxall points out that the older sea ice is, the less salt it =20 contains. Ice that=92s two or three years old already contains very =20 little salt. [NEWSPAPER ARTICLE ENDED RIGHT HERE, WITH NO INDICATION THAT THERE =20 WAS MORE OF THE ARTICLE THAT WAS ELSEWHERE OR JUST LEFT OUT][JW] Year-old ice, however, remains fairly salty. And when it melts, it =20 produces meltwater that's denser than the relatively fresh water from =20= older ice. As multi-year ice declines throughout the Arctic, more of the saltier =20= meltwater from younger ice is mixing into the ocean. That colder, =20 denser water sinks more quickly and forces less dense water from =20 deeper in the ocean up to the surface. Because fresh meltwater is colder than seawater, that means =20 relatively warm water is being forced upwards. And that, said Boxall, =20= may be part of the reason that sea ice is melting so much faster than =20= anyone thought it would. ``What we're seeing is that (fresh meltwater) being taken away from =20 the surface and replaced by slightly warmer water,'' said Boxall. =20 ``The evidence is that the surface waters are (now) slightly warmer.'' Boxall cautions that his conclusions are based on a preliminary =20 review of data that the team brought back from the ice. ``We need to compare our results with previous data and with groups =20 from other areas.'' A paper is being prepared for publication. The results do show that the effects of climate change and global =20 warming are not always obvious, suggested Boxall. ``The evidence is that there's something interesting going on. The =20 fact that (the climate) is getting warmer is one reason for the ice =20 melting, but it's more complex than that.''= --Boundary_(ID_EXJDfupp1rqX3R7g2sk/mA) Content-type: text/html; charset=WINDOWS-1252 Content-transfer-encoding: quoted-printable <html><body style=3D"word-wrap: break-word; -webkit-nbsp-mode: space; = -webkit-line-break: after-white-space; "><div style=3D"margin-top: 0px; = margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font = face=3D"Helvetica" size=3D"3" style=3D"font: 12.0px Helvetica">For those = interested, note how much of this article was left out of the printed = newspaper, at least for the Valley edition, versus what was on the = Herald Web site. Cheers from Jim in Wolfville</font></div><div = style=3D"margin-top: 0px; margin-right: 0px; margin-bottom: 0px; = margin-left: 0px; "><font face=3D"Helvetica" size=3D"3" style=3D"font: = 12.0px Helvetica">-----------------------------</font></div><div = style=3D"margin-top: 0px; margin-right: 0px; margin-bottom: 0px; = margin-left: 0px; "><font face=3D"Helvetica" size=3D"3" style=3D"font: = 12.0px Helvetica"><br></font></div><div style=3D"margin-top: 0px; = margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font = face=3D"Helvetica" size=3D"3" style=3D"font: 12.0px Helvetica">Chronicle = Herald, Tuesday, June 28, 2011</font></div><div style=3D"margin-top: = 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: = normal normal normal 12px/normal Helvetica; min-height: 14px; = "><br></div><div style=3D"margin-top: 0px; margin-right: 0px; = margin-bottom: 0px; margin-left: 0px; "><font face=3D"Helvetica" = size=3D"3" color=3D"#001ee6" style=3D"font: 12.0px Helvetica; color: = #001ee6"><a = href=3D"http://thechronicleherald.ca/Canada/1250711.html">http://thechroni= cleherald.ca/Canada/1250711.html</a></font></div><div style=3D"margin-top:= 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: = normal normal normal 12px/normal Helvetica; min-height: 14px; = "><br></div><div style=3D"margin-top: 0px; margin-right: 0px; = margin-bottom: 0px; margin-left: 0px; line-height: 35px; "><font = face=3D"Georgia" size=3D"7" style=3D"font: 32.0px Georgia">Walkers help = solve mystery of fast melt </font></div><div style=3D"margin-top: = 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; = line-height: 35px; font: normal normal normal 12px/normal Ar