Posted on 09/01/2002 7:31:02 PM PDT by FireTrack
Perhaps you have seen the first installments of the series on the arctic meltdown that the CBS TV network is doing for sweeps month. In the first piece they discussed how the arctic region has warmed dramatically in recent years and showed how the arctic ice has retreated along the edges and grown thinner. They promise to have scientists report on the possible cause in follow-up stories this week.
They focused on changes near the Arctic Ocean town of Barrow, Alaska. Ice had retreated from the shoreline near Barrow and temperatures have warmed accordingly. They talked about mosquitos being observed, not uncommon in Alaska but usually not seen on the north arctcic shoreline. They also reported that the temperatures have warmed 4 degrees in Barrow in the last 30 years.
When we look at temperatures in Barrow, we indeed see a warm up in the last 20 years with a large spike in the last super El Nino of 1997/98. If you remove that one year outlier, what remains in the temperature is an apparent cyclical wave that shows warming in the 1930s and 1940s and then cooling through the 1950s, 1960s and 1970s followed by the recent decadal warming.
Annual Mean temperatures (degrees Celsius) for Barrow, Alaska from NASA GISS.
In a prior story we showed how this cyclical change in temperatures and change in the northern hemispheric polar ice relate to the large-scale circulations in the Pacific and Atlantic Oceans (and to the longer term colar cycles). We showed how well temperatures in Fairbanks related to the large-scale oceanic cycles, especially the Pacific cycle called the Pacific Decadal Oscillation or PDO.
The Pacific Decadal Oscillationor PDO is a large-scale flip-flop in ocean temperature and atmospheric pressure patterns that tends to occur every few decades. We have apparently returned to the cool phase in the last two years after two decades in the so-called warm phase.
Fairbanks, Alaska showed a very similar wave in the temperature.
Fairbanks annual mean temperatures change dramatically with the phases of the Pacific Decadal Oscillation.
The PDO in conjunction with the North Atlantic Oscillation (NAO) also affects the ice thickness through their effects on ocean currents in the arctic. During the warm phases of the oceanic cycles, there is an increased current flow beneath the arctic ice that melts the snow and ice from beneath and moves ice out of the arctic basin more rapidly (unlike the Antarctic which is ice on land, the arctic ice is a floating icecap).
A new NASA Goddard story discusses the importance of a large-scale planetary wave in the atmosphere in relation to the transport of the arctic ice through the Fram Strait The wave they talk about probably relates to the PDO phase as the ice extent shown below changes with changes in the mean phase of the PDO.
Like the polar temperatures, the arctic ice seems to change with the PDO cycle. Arctic ice extent dropped dramatically in the late 1970s and then slowly declined through the middle 1990s. A slow increase may have begun after that. The PDO changed phase in 1977 from cold to warm and then again around 1997 from warm to cold.
It has been around half a century since the last PDO warm phase and it is not surprising that most people do not remember the concerns about the declines in arctic ice and warm temperatures then. More people remember the widespread speculation about the impending ice age during the cold and snowy 1960s and 1970s. Now we are led to believe this current warm spell is just a start of what could be a disastrous climate change.
This too will probably pass. Perhaps a lot sooner than most people could imagine.
I'm not sure but don't we have about 10 times as many automobiles now than we did in 1940? If that's the case we should all be burnt to a crisp from global warming.
Anybody know of a website where this old ditty-bop can go to refresh his skills?
So we have global warming. So what?
I have heard that theory too. I wish I had heard it before I went there and saw the glacier footprint maps. I didn't think to compare the temps to the footprints.
This data is available. It frosts me no end that it isn't published in the popular media so we can all see it and come to our own conclusions.
But that wouldn't advance the "politically correct" argument, would it?
You're confusing the ice shelf with the glaciers. They are two different things. It's true that the Arctic ice shelf is over water, and the Antarctic ice shelf is over land and water, but the glaciers in Alaska that are used as evidence of "global warming" are primarily over land.
And, BTW, the Arctic ice shelf melts somewhat every summer.
I spent eight years working in the oilfields up there in Prudhoe Bay, on the Arctic coast, and let me tell you the mosquito clouds darked the sun at times. They would get under the hem of my pants and bite any flesh they could find as they crawled up my legs. I have never seen any that were more blood thirsty.
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