Sunday, March 07, 2010
Wet winter builds above-average Sierra snowpack
By Cathy Bussewitz, The Associated Press
SACRAMENTO - California's wet winter has left an above-average snowpack in the Sierra Nevada, boosting prospects for additional water deliveries to cities and farms, water officials said on Wednesday.
But the California Department of Water Resources cautioned that the winter rain and snow was not enough to fully offset three previous years of drought.
The average water content contained in the Sierra snowpack is 107 percent of normal, according to Wednesday's snow survey, the third of five that will be conducted this winter. Last year at this time, the water content was 80 percent of normal.
The snowpack is important because its runoff provides much of the state's water supply in the summer.
If wet weather continues, the department says the State Water Project will be able to deliver 35 percent to 45 percent of requested amounts of water.
But the water level is not enough to end the drought, said Frank Gehrke, Chief of California Snow Surveys. He explained that though the state didn't lose any water content, it gained less than he hoped in the February because there were a few weeks without snow.
"We're kind of marching in place in terms of what it means for reservoir recovery," Gehrke said.
Despite recent storms, the water level at Lake Oroville, the principal storage reservoir for the State Water Project, was only at 55 percent of average for this time of year.
Electronic sensor readings showed the northern Sierra snow water equivalents at 126 percent of normal, central Sierra at 93 percent, and southern Sierra at 109 percent.
"We must remember that even a wet winter will not fully offset three consecutive dry years or pumping restrictions to protect Delta fish, so we must continue to conserve and protect our water resources," said Mark Cowin, director of the Department of Water Resources.
SACRAMENTO - California's wet winter has left an above-average snowpack in the Sierra Nevada, boosting prospects for additional water deliveries to cities and farms, water officials said on Wednesday.
But the California Department of Water Resources cautioned that the winter rain and snow was not enough to fully offset three previous years of drought.
The average water content contained in the Sierra snowpack is 107 percent of normal, according to Wednesday's snow survey, the third of five that will be conducted this winter. Last year at this time, the water content was 80 percent of normal.
The snowpack is important because its runoff provides much of the state's water supply in the summer.
If wet weather continues, the department says the State Water Project will be able to deliver 35 percent to 45 percent of requested amounts of water.
But the water level is not enough to end the drought, said Frank Gehrke, Chief of California Snow Surveys. He explained that though the state didn't lose any water content, it gained less than he hoped in the February because there were a few weeks without snow.
"We're kind of marching in place in terms of what it means for reservoir recovery," Gehrke said.
Despite recent storms, the water level at Lake Oroville, the principal storage reservoir for the State Water Project, was only at 55 percent of average for this time of year.
Electronic sensor readings showed the northern Sierra snow water equivalents at 126 percent of normal, central Sierra at 93 percent, and southern Sierra at 109 percent.
"We must remember that even a wet winter will not fully offset three consecutive dry years or pumping restrictions to protect Delta fish, so we must continue to conserve and protect our water resources," said Mark Cowin, director of the Department of Water Resources.
Saturday, March 06, 2010
Weekly Drought Monitor - as of March 2nd, 2010
Friday, March 05, 2010
Undersea Arctic methane could wreak havoc on climate
FROM: USA Today
By Doyle Rice, USA TODAY
It lurks beneath the sea.
No, not The Blob, but something perhaps far more sinister: methane, a potent greenhouse gas 30 times better than carbon dioxide at trapping atmospheric heat.
Research released Thursday finds that underground methane appears to be seeping through the Arctic Ocean floor and into the Earth's atmosphere, thanks to a weakening of the protective layer of permafrost at the bottom of the ocean. Once released into the atmosphere, methane could wreak havoc with the world's climate.
Although scientists have known about the methane under the Arctic— and its potential for leakage — since the 1990s, the study is the first to document it to this degree.
"The release to the atmosphere of only 1% of the methane assumed to be stored in shallow hydrate deposits" could increase the level of atmospheric methane worldwide by three or four times, says the study's lead author, Natalia Shakhova, a researcher at the University of Alaska-Fairbanks. That could trigger abrupt climate warming, the authors report. But the specific climate consequences are hard to predict, they say.
The researchers studied the East Siberian Arctic Shelf, a section of the Arctic Ocean just north of Siberia.
Historically, methane concentrations in the world's atmosphere have ranged between 0.3 and 0.4 parts per million in cool periods to 0.6 to 0.7 in warm periods. Current methane concentrations in the Arctic average about 1.85 parts per million, the scientists said, the highest in 400,000 years.
"The amount of methane currently coming out of the East Siberian Arctic Shelf is comparable to the amount coming out of the entire world's oceans," Shakhova says. "Subsea permafrost is losing its ability to be an impermeable cap."
Permafrost, which occurs throughout the Arctic, is a layer of soil or rock at which the temperature has been continuously below 32 degrees for at least several years, according to the National Snow and Ice Data Center.
Methane is released when organic material in the thawing permafrost decomposes, which gradually releases methane. It also can be released directly as stored methane already in the permafrost is released as it thaws.
Why is the permafrost failing? According to the study, the process occurs naturally over thousands of years but is being accelerated by man-made climate warming. "Sustained release of methane to the atmosphere from thawing Arctic permafrost is a likely positive feedback to climate warming," the authors write in the study, which appears in the new edition of the journal Science.
The East Siberian Arctic Shelf, in addition to holding large stores of frozen methane, is an additional concern because it is so shallow. In deep water, methane gas oxidizes into carbon dioxide before it reaches the surface. In the shallow East Siberian Arctic Shelf, methane simply doesn't have enough time to oxidize, which means more of it escapes into the atmosphere.
This is a new topic, Shakhova concedes, and the findings are only a starting point for further study.
"We're at the very beginning of studying this topic," Shakhova says. "This has never been incorporated into climate models."
Contributing: Associated Press
By Doyle Rice, USA TODAY
It lurks beneath the sea.
No, not The Blob, but something perhaps far more sinister: methane, a potent greenhouse gas 30 times better than carbon dioxide at trapping atmospheric heat.
Research released Thursday finds that underground methane appears to be seeping through the Arctic Ocean floor and into the Earth's atmosphere, thanks to a weakening of the protective layer of permafrost at the bottom of the ocean. Once released into the atmosphere, methane could wreak havoc with the world's climate.
Although scientists have known about the methane under the Arctic— and its potential for leakage — since the 1990s, the study is the first to document it to this degree.
"The release to the atmosphere of only 1% of the methane assumed to be stored in shallow hydrate deposits" could increase the level of atmospheric methane worldwide by three or four times, says the study's lead author, Natalia Shakhova, a researcher at the University of Alaska-Fairbanks. That could trigger abrupt climate warming, the authors report. But the specific climate consequences are hard to predict, they say.
The researchers studied the East Siberian Arctic Shelf, a section of the Arctic Ocean just north of Siberia.
Historically, methane concentrations in the world's atmosphere have ranged between 0.3 and 0.4 parts per million in cool periods to 0.6 to 0.7 in warm periods. Current methane concentrations in the Arctic average about 1.85 parts per million, the scientists said, the highest in 400,000 years.
"The amount of methane currently coming out of the East Siberian Arctic Shelf is comparable to the amount coming out of the entire world's oceans," Shakhova says. "Subsea permafrost is losing its ability to be an impermeable cap."
Permafrost, which occurs throughout the Arctic, is a layer of soil or rock at which the temperature has been continuously below 32 degrees for at least several years, according to the National Snow and Ice Data Center.
Methane is released when organic material in the thawing permafrost decomposes, which gradually releases methane. It also can be released directly as stored methane already in the permafrost is released as it thaws.
Why is the permafrost failing? According to the study, the process occurs naturally over thousands of years but is being accelerated by man-made climate warming. "Sustained release of methane to the atmosphere from thawing Arctic permafrost is a likely positive feedback to climate warming," the authors write in the study, which appears in the new edition of the journal Science.
The East Siberian Arctic Shelf, in addition to holding large stores of frozen methane, is an additional concern because it is so shallow. In deep water, methane gas oxidizes into carbon dioxide before it reaches the surface. In the shallow East Siberian Arctic Shelf, methane simply doesn't have enough time to oxidize, which means more of it escapes into the atmosphere.
This is a new topic, Shakhova concedes, and the findings are only a starting point for further study.
"We're at the very beginning of studying this topic," Shakhova says. "This has never been incorporated into climate models."
Contributing: Associated Press
Thursday, March 04, 2010
Blusterly, partly cloudy morning in the desert
Tuesday, March 02, 2010
Chile Quake Speeds Up Earth's Rotation, Trims Day
NEW YORK (AP) - Earth's days may have gotten a little bit shorter since the massive earthquake in Chile, but don't feel bad if you haven't noticed.
The difference would be only about one-millionth of a second.
Richard Gross, a scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif., and colleagues calculated that Saturday's quake shortened the day by 1.26 microseconds. A microsecond is one-millionth of a second.
The length of a day is the time it takes for the planet to complete one rotation - 86,400 seconds or 24 hours.
An earthquake can make Earth rotate faster by nudging some of its mass closer to the planet's axis, just as ice skaters can speed up their spins by pulling in their arms. Conversely, a quake can slow the rotation and lengthen the day if it redistributes mass away from that axis, Gross said Tuesday.
Gross said the calculated changes in length of the day are permanent. So a bunch of big quakes could add up to make the day shorter, "but these changes are very, very small."
So small, in fact, that scientists can't record them directly. Gross said actual observations of the length of the day are accurate to five-millionths of a second. His estimate of the effect of the Chile quake is only a quarter of that span.
"I'll certainly look at the observations when they come in," Gross said, but "I doubt I'll see anything."
On the Net:
http://www.jpl.nasa.gov/index.cfm
The difference would be only about one-millionth of a second.
Richard Gross, a scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif., and colleagues calculated that Saturday's quake shortened the day by 1.26 microseconds. A microsecond is one-millionth of a second.
The length of a day is the time it takes for the planet to complete one rotation - 86,400 seconds or 24 hours.
An earthquake can make Earth rotate faster by nudging some of its mass closer to the planet's axis, just as ice skaters can speed up their spins by pulling in their arms. Conversely, a quake can slow the rotation and lengthen the day if it redistributes mass away from that axis, Gross said Tuesday.
Gross said the calculated changes in length of the day are permanent. So a bunch of big quakes could add up to make the day shorter, "but these changes are very, very small."
So small, in fact, that scientists can't record them directly. Gross said actual observations of the length of the day are accurate to five-millionths of a second. His estimate of the effect of the Chile quake is only a quarter of that span.
"I'll certainly look at the observations when they come in," Gross said, but "I doubt I'll see anything."
On the Net:
http://www.jpl.nasa.gov/index.cfm
Monday, March 01, 2010
State may ban plants from using ocean as coolant
LOS ANGELES (AP) -- State water board regulators are mulling a plan to stop power companies from vacuuming the ocean for water to cool their machinery.
Environmentalists say the practice destroys too much sea life, while utility advocates say the impact is minimal. They say banning the practice would cost too much, jeopardize the reliability of the electricity grid and slow the state's transition to clean energy.
The State Water Resources Control Board's proposal would require plants to supplant seawater pipes with massive cooling towers that recycle water. Power plants could also use air-cooling platforms.
It was not immediately clear when the board would vote on the issue.
Environmentalists say the practice destroys too much sea life, while utility advocates say the impact is minimal. They say banning the practice would cost too much, jeopardize the reliability of the electricity grid and slow the state's transition to clean energy.
The State Water Resources Control Board's proposal would require plants to supplant seawater pipes with massive cooling towers that recycle water. Power plants could also use air-cooling platforms.
It was not immediately clear when the board would vote on the issue.
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