Global Warming ??????????????
Alaska glaciers grew this year, thanks to colder weather
By Craig Medred | Anchorage Daily News
MASS BALANCE: For decades, summer snow loss has exceeded winter snowfall.
Oct. 13, 2008
Two hundred years of glacial shrinkage in Alaska, and then came the winter and summer of 2007-2008.
Unusually large amounts of winter snow were followed by unusually chill temperatures in June, July and August.
Click to enlarge
"In mid-June, I was surprised to see snow still at sea level in Prince William Sound," said U.S. Geological Survey glaciologist Bruce Molnia. "On the Juneau Icefield, there was still 20 feet of new snow on the surface of the Taku Glacier in late July. At Bering Glacier, a landslide I am studying, located at about 1,500 feet elevation, did not become snow free until early August.
"In general, the weather this summer was the worst I have seen in at least 20 years."
Never before in the history of a research project dating back to 1946 had the Juneau Icefield witnessed the kind of snow buildup that came this year. It was similar on a lot of other glaciers too.
"It's been a long time on most glaciers where they've actually had positive mass balance," Molnia said.
That's the way a scientist says the glaciers got thicker in the middle.
Mass balance is the difference between how much snow falls every winter and how much snow fades away each summer. For most Alaska glaciers, the summer snow loss has for decades exceeded the winter snowfall.
The result has put the state's glaciers on a long-term diet. Every year they lose the snow of the previous winter plus some of the snow from years before. And so they steadily shrink.
Since Alaska's glacial maximum back in the 1700s, Molnia said, "I figure that we've lost about 15 percent of the total area."
What might be the most notable long-term shrinkage has occurred at Glacier Bay, now the site of a national park in Southeast Alaska. When the first Russian explorers arrived in Alaska in the 1740s, there was no Glacier Bay. There was simply a wall of ice across the north side of Icy Strait.
That ice retreated to form a bay and what is now known as the Muir Glacier. And from the 1800s until now, the Muir Glacier just kept retreating and retreating and retreating. It is now back 57 miles from the entrance to the bay, said Tom Vandenberg, chief interpretative ranger at Glacier Bay.
That's farther than the distance from glacier-free Anchorage to Girdwood, where seven glaciers overhang the valley surrounding the state's largest ski area. The glaciers there, like the Muir and hundreds of other Alaska glaciers, have been part of the long retreat.
Overall, Molnia figures Alaska has lost 10,000 to 12,000 square kilometers of ice in the past two centuries, enough to cover an area nearly the size of Connecticut.
Molnia has just completed a major study of Alaska glaciers using satellite images and aerial photographs to catalog shrinkage. The 550-page "Glaciers of Alaska" will provide a benchmark for tracking what happens to the state's glaciers in the future.
Climate change has led to speculation they might all disappear. Molnia isn't sure what to expect. As far as glaciers go, he said, Alaska's glaciers are volatile. They live life on the edge.
"What we're talking about to (change) most of Alaska's glaciers is a small temperature change; just a small fraction-of-a-degree change makes a big difference. It's the mean annual temperature that's the big thing.
"All it takes is a warm summer to have a really dramatic effect on the melting.''
Or a cool summer to shift that mass balance the other way.
One cool summer that leaves 20 feet of new snow still sitting atop glaciers come the start of the next winter is no big deal, Molnia said.
Ten summers like that?
Well, that might mark the start of something like the Little Ice Age.
During the Little Ice Age -- roughly the 16th century to the 19th -- Muir Glacier filled Glacier Bay and the people of Europe struggled to survive because of difficult conditions for agriculture. Some of them fled for America in the first wave of white immigration.
The Pilgrims established the Plymouth Colony in December 1620. By spring, a bitterly cold winter had played a key role in helping kill half of them. Hindered by a chilly climate, the white colonization of North America through the 1600s and 1700s was slow.
As the climate warmed from 1800 to 1900, the United States tripled in size. The windy and cold city of Chicago grew from an outpost of fewer than 4,000 in 1800 to a thriving city of more than 1.5 million at the end of that century.
The difference in temperature between the Little Ice Age and these heady days of American expansion?
About three or four degrees, Molnia said.
The difference in temperature between this summer in Anchorage -- the third coldest on record -- and the norm?
About three degrees, according to the National Weather Service.
Does it mean anything?
Nobody knows. Climate is constantly shifting. And even if the past year was a signal of a changing future, Molnia said, it would still take decades to make itself noticeable in Alaska's glaciers.
Rivers of ice flow slowly. Hundreds of feet of snow would have to accumulate at higher elevations to create enough pressure to stall the current glacial retreat and start a new advance. Even if the glaciers started growing today, Molnia said, it might take up to 100 years for them to start steadily rolling back down into the valleys they've abandoned.
"It's different time scales," he said. "We're just starting to understand."
As strange it might seem, Alaska's glaciers could appear to be shrinking for some time while secretly growing. Molnia said there are a few glaciers in the state now where constant snow accumulations at higher elevations are causing them to thicken even as their lower reaches follow the pattern of retreat fueled by the global warming of recent decades.
Find Craig Medred online at adn.com/contact/cmedred or call 257-4588.
www.adn.com/news/environment/story/555283.html
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Weekend cold set new record lows
Pendleton breaks 118-year-old record
Monday, October 13, 2008
Cold temperatures set several new record lows this weekend, including a low of 22 Saturday in downtown Pendleton that broke a 118 year-old record of 24.
Record lows started falling Thursday with a new low of 20 for Meacham, four degrees cooler than the previous record from 2006, according to information from the Web site for the National Weather Service Forecast Office in Pendleton.
Heppner and Long Creek then set new low temperatures Friday. Heppner hit 29, the coldest that date has seen since 1960 when it was 30; and Long Creek was 21, besting the 1987 record by four degrees.
Saturday set multiple new lows, including the record 22 in downtown Pendleton. John Day dropped to 21, breaking the 1990 record of 23; Meacham's 15 broke the previous low of 20 from 2002; and Mitchell set a record with 21, five degrees cooler than the 2002 record.
Additionally, the top of Airport Hill in Pendleton set a new low of 25; the previous record was 33. And the agricultural experimental station north of Pendleton recorded a low of 18, five degrees cooler than the previous record from 1990.
The cold continued to set records Sunday. Meacham, for the third time in four days, set a record with a low of 15, one degree cooler than the 2002 record. Long Creek and Mitchell again set new records as well Long Creek's low of 21 broke with 1969 record of 25, and Mitchell's 21 broke the 1949 record of 24.
The top of Airport Hill in Pendleton also set another record with 24; the previous record was 28 from 2002. And downtown Pendleton's 21 chilled past the previous record of 25 from 1931.
Also Sunday, two-miles north of Hermiston cooled to 18, breaking the 1953 record of 20.
Weather this week, however, won't be so chilly as the past few days. Eastern Oregon will have partly sunny to mostly sunny days and high temperatures in the 60s. Overnight lows this week will be primarily in the upper-30s and lower-40s.
Today's highs will be in the mid-60s and overnight lows in the mid-40s. High temperatures will drop to about the lower-60s Tuesday and then to around the mid-50s Wednesday.
Thursday, however, will warm and some cities will have highs in the upper-60s. Temperatures will cool a little going into the weekend, but most area highs will remain in the mid-60s.
Pendleton today will be partly sunny with a high near 66. There also will be a 7 mph southeast wind that will change to west-southwest. Tonight will be mostly cloudy with a low near 43 and southwest wind 8-13 mph.
Tuesday will be partly sunny with a high near 61 and west southwest wind between 8-11 mph. Tuesday night will be mostly cloudy with a low around 36 and west-southwest wind around 6 mph.
Wednesday also will be partly sunny but the high will be around 56. There also will be a south wind around 5 mph becoming west. The overnight low will be near 33.
Thursday and Friday will be mostly sunny with a highs 67-67 and overnight lows around 38. Saturday will be partly sunny with a high near 65 and a low around 34. Sunday will be similar, with a high near 64.
Hermiston will be partly sunny today with a high near 66 and a 5-8 mph southwest wind. Tonight will be mostly cloudy with a low around 45 and a 9-13 mph west-southwest wind.
Tuesday will be mostly sunny with a high near 62 and an 8-11 mph west-southwest wind. Tuesday night will be partly cloud with a low around 39 and a 6 mph west-southwest wind.
Wednesday will be partly sunny, but the high will be near 59 and there will be a west- southwest wind around 6 mph. Wednesday night will be partly cloudy with a low around 38.
Thursday will warm to about 68 and be mostly sunny. The overnight low will be around 39.
Friday also will be mostly sunny with a high near 65. The night will be mostly cloudy with a low around 43.
Saturday will be partly sunny and the temperature will reach about 67. The night will be mostly cloudy and the low about 38. Sunday will be partly sunny and have a high around 66.
Pilot Rock will be partly sunny today with a high near 63 and a 7 mph south-southeast wind changing to west-southwest. Tonight will be mostly cloudy with a low around 42 and west- southwest wind 7-10 mph.
Tuesday will be partly sunny with a high near 58 and 7-9 mph west wind. The night will be mostly cloudy with a low around 41 and a 5 mph west-southwest wind.
Wednesday also will be partly sunny but the high will be near 55 with a south wind at 5 mph becoming west-northwest. Wednesday night will be partly cloudy with a low around 38.
Thursday will be mostly sunny with a high near 65, and that night will be partly cloudy with a low around 38.
Friday will be mostly sunny with a high near 63 and an overnight low around 42. Saturday will be partly sunny with a high around 62 and a nighttime low near 38. Sunday will be partly sunny and reach about 62.
Milton-Freewater will be partly sunny today with a high near 64 and an 8 mph south-southwest wind. Tonight will be mostly cloudy with a low around 46 and southwest wind 8-11 mph.
Tuesday will be mostly sunny and reach about 60 with a 7-10 mph southwest wind. Tuesday night will be partly cloudy with a low near 41 and a 6 mph southwest wind.
Wednesday will be partly sunny with a high near 57 and a 5 mph west-southwest wind. That night will be partly cloudy with a low around 39.
Thursday through Saturday will be mostly sunny. Thursday will reach about 67 with an overnight low around 41. Friday will be about 62 and have an overnight low near 44. Saturday will hit about 65 and cool overnight to about 38. Sunday will be partly sunny with a high near 64.
Heppner will be partly sunny today with a high near 64 and an 8 mph southwest wind. Tonight will be mostly cloudy with a low around 44 and 9-11 mph west wind.
Tuesday will be partly sunny with a high around 59 and west wind 8-10 mph. Tuesday night will be mostly cloudy with a low around 39 and a 7 mph west-southwest wind.
Wednesday will be partly sunny with a high near 56 and a 6 mph west-southwest wind. Wednesday night will be partly cloudy with a low around 39.
Thursday and Friday will be mostly sunny. Thursday's high will be about 66 and have an overnight low near 39. Friday will hit about 63 and have a nighttime low near 43.
Saturday will be partly sunny with a high near 62 and an overnight low near 36. Sunday will be partly sunny with a low around 36.
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Frost 'one more thing' for grape growers
Last Modified: Tuesday, October 14, 2008 at 5:26 a.m.
A record cold snap in Mendocino County over the weekend caused little damage to wine grapes but chilled the hearts of farmers who already have suffered huge losses this year.
"It's just one more thing on top of one more thing. You kind of hold your breath," said Potter Valley wine grape grower Bill Pauli.
Temperatures dropped to 31 degrees in the Ukiah Valley on Saturday night and early Sunday morning, the coldest Oct. 12 morning since record keeping began in Ukiah in 1893, said Troy Nicolini, a meteorologist with the National Weather Service in Eureka. The previous record was 34 degrees in 1916.
Temperatures were milder in Sonoma County, and there were no reports of frost-related problems, county officials said.
Farmers in Redwood Valley and other cooler regions in Mendocino County reported temperatures as low as 27 degrees.
An estimated 30 percent to 50 percent of that county's wine grape crop had yet to be harvested when the frost hit, killing the tops of unprotected vines and effectively freezing the ripening process.
Most unprotected wine grape crops already had adequate sugar content, so they were unharmed, said Mendocino County Agricultural Commissioner Dave Bengston.
Farmers either sprayed water or turned on wind machines for crops that were not quite ready to harvest, said Redwood Valley farmer Peter Johnson. He said he took frost-protection measures for his cabernet and merlot grapes and expects the return of sunny weather to bump up their sugar content over the next week or two.
Mendocino County wine-grape growers were fearful because they already had lost an estimated 30 percent of their crop to frost in the early spring. The crop also was hit by an early rain that threatened to cause rot, and the region endured a wildfire-choked summer that had the potential to cause smoke damage.
"It'll be nice to get this one put in the barn and put behind us," Pauli said.
Despite the hazardous conditions, Mendocino County's wine-grape crop is looking good, said Paige Poulos, president of the Mendocino Winegrape and Wine Commission.
"We had wonderful fruit, just not enough of it," she said.
Area grape growers are expect to finish harvesting in the next two weeks, sooner if the weather turns cold again.
You can reach Staff Writer Glenda Anderson at 462-6473 or glenda.anderson@pressdemocrat.com.