Showing posts with label Mt Fuji. Show all posts
Showing posts with label Mt Fuji. Show all posts

Monday, April 6, 2009

Atlantic Ocean Warming Dust Driven

This is a little unexpected. It is not unexpected that dust is a contributor but the magnitude certainly is. It appears that two thirds of the regional temperature gain can be attributed to dust and volcanic ash.

This also clarifies the feedback mechanism. We forget the heat gathering capacity of ocean water as compared to land because is attenuated through a thick upper layer. Land either absorbs and uses the energy chemically or reflects it back into the atmosphere. Thus the ocean has a stable temperature regime whose variation is minor as remarked on here. However a one degree rise represents a major jump in heat content in the water that will discharge into the atmosphere producing storms.

A modest amount of dust in the atmosphere generated major reduction in the driving heat engine.

The clear lesson is that a major volcanic interlude will be felt strongly in terms of climate change.

This returns me to contemplation on the possible causes of the worst climate experiences of the little ice age.
Assuming that we were on the low end of the normal Holocene climate variation, the injection of volcanic dust would have been rather damaging. And it need not be a overly big event. I recall that Fuji erupted in a timely manner and its position is such as to possibly affect European climate through high level aerosols and dust.

Thus provided that we already had a modest reduction is temperature due to a very slightly cooler sun, an inconvenient volcano could easily wreck a years climate while not even been noticed.

Dust Responsible for Most of Atlantic Warming

posted: 26 March 2009 02:15 pm ET

The warming of Atlantic Ocean waters in recent decades is largely due to declines in airborne dust from African deserts and lower volcanic emissions, a new study suggests.

Since 1980, the tropical North Atlantic has been warming by an average of a half-degree Fahrenheit (a quarter-degree Celsius) per decade.

While that number may sound small, it can translate to big impacts on hurricanes, which are
fueled by warm surface waters, said study team member Amato Evan of the University of Wisconsin-Madison. For example, the ocean temperature difference between 1994, a quiet hurricane year, and 2005's record-breaking year of storms (including Hurricane Katrina), was just 1 degree Fahrenheit.

Evan and his colleagues had previously shown that African dust and other airborne particles can suppress hurricane activity by reducing how much sunlight reaches the ocean and keeping the sea surface cool. Dusty years predict mild hurricane seasons, while years with low dust activity — including 2004 and 2005 — have been linked to stronger and more frequent storms.

In the new study, the researchers investigated the exact effect of dust and volcanic emissions on ocean temperatures. They combined satellite data of dust and other particles with existing climate models and calculated how much of the Atlantic warming observed during the last 26 years could be accounted for by simultaneous changes in African dust storms and tropical volcanic activity, primarily the eruptions of El Chichón in Mexico in 1982 and
Mount Pinatubo in the Philippines in 1991.

The results: More than two-thirds of this upward trend in recent decades can be attributed to changes in African dust storm and tropical volcano activity during that time.

This was a surprisingly large amount, Evan said.

The results, detailed in the March 27 issue of the journal Science, suggest that only about 30 percent of the observed Atlantic temperature increases are due to other factors, such as
a warming climate.

"This makes sense, because we don't really expect global warming to make the ocean [temperature] increase that fast," Evan said.

This adjustment brings the estimate of global warming's impact on the Atlantic more in line with the smaller degree of ocean warming seen elsewhere, such as the Pacific.

Of course, this doesn't discount the importance of global warming, Evan said, but indicates that newer climate models will need to include dust storms as a factor to accurately predict how ocean temperatures will change.

Satellite research of dust-storm activity is relatively young, and no one yet understands what drives dust variability from year to year. And volcanic eruptions are still relatively unpredictable.

"We don't really understand how dust is going to change in these climate projections, and changes in dust could have a really good effect or a really bad effect," Evan said.

More research and observations of the impact of dust will help answer that question.

Monday, March 2, 2009

Winter 1709

Around the end of the Little Ice Age, Europe experienced this awful winter that was recognized as the worst experienced and can be accepted as that because of the living knowledge of the time and place. This article gives us a good description and plenty of data and some suggestive ideas.

The default explanation for the Little Ice Age has been a drop in solar output. The only thing that makes me uncomfortable with that explanation is that we lack good global confirmation. In fact one gets the sense that the rest of the globe was simply unaffected and that the European chill resulted from a confluence of bad luck in the year’s weather.

We had both Vesuvius and Fuji banging away, but they are really insufficient. The unusual impact of the southern winds is notable only inasmuch as their expected effect failed to materialize.

Once again, we have no knowledge of the activity of the Alaskan volcanoes that could well have the capacity to impact northern climate. And that really says it all. We have blank spots in the global record book that needs to be extracted somehow. We need to properly determine the ejection history of all active volcanoes around the world, even if it is to eliminate their influence.

A more important observation is that the reported temperatures are not particularly dangerous. Cold yes, but certainly well within our working comfort level for all of Europe. It was mostly an inconvenience to most that lived through it. The temperatures quoted are comparable to the continental weather of the Midwest every year. They are not comparable to those of Northern Alberta.

Another observation is that the rebound was rapid over the next two decades. This is the mirror of the present day reversal been experienced. Whatever confluence of atmospheric dynamics takes place, it seems recoil immediately toward the equilibrium position.

1709: The year that Europe froze

07 February 2009 by
Stephanie Pain

People across Europe awoke on 6 January 1709 to find the temperature had plummeted. A three-week freeze was followed by a brief thaw - and then the mercury plunged again and stayed there. From Scandinavia in the north to Italy in the south, and from Russia in the east to the west coast of France, everything turned to ice. The sea froze. Lakes and rivers froze, and the soil froze to a depth of a metre or more. Livestock died from cold in their barns, chicken's combs froze and fell off, trees exploded and travellers froze to death on the roads. It was the coldest winter in 500 years.

IN ENGLAND they called the winter of 1709 the Great Frost. In France it entered legend as Le Grand Hiver, three months of deadly cold that ushered in a year of famine and food riots. In Scandinavia the Baltic froze so thoroughly that people could walk across the ice as late as April. In Switzerland hungry wolves crept into villages. Venetians skidded across their frozen lagoon, while off Italy's west coast, sailors aboard English men-of-war died from the cold. "I believe the Frost was greater (if not more universal also) than any other within the Memory of Man," wrote William Derham, one of England's most meticulous meteorological observers. He was right. Three hundred years on, it holds the record as the coldest European winter of the past half-millennium.

Derham was the Rector of Upminster, a short ride north-east of London. He had been checking his thermometer and barometer three times a day since 1697. Similarly dedicated observers scattered across Europe did much the same and their records tally remarkably closely. On the night of 5 January, the temperature fell dramatically and kept on falling. On 10 January, Derham logged -12 °C, the lowest temperature he had ever measured. In France, the temperature dipped lower still. In Paris, it sank to -15 °C on 14 January and stayed there for 11 days. After a brief thaw at the end of that month the cold returned with a vengeance and stayed until mid-March.

Later that year, Derham wrote a detailed account of the freeze and the destruction it caused for the Royal Society's Transactions. Fish froze in the rivers, game lay down in the fields and died, and small birds perished by the million. The loss of tender herbs and exotic fruit trees was no surprise, but even hardy native oaks and ash trees succumbed. The loss of the wheat crop was "a general calamity". England's troubles were trifling, however, compared to the suffering across the English Channel.
In France, the freeze gripped the whole country as far as the Mediterranean. Even the king and his courtiers at the sumptuous Palace of Versailles struggled to keep warm. The Duchess of Orleans wrote to her aunt in Germany: "I am sitting by a roaring fire, have a screen before the door, which is closed, so that I can sit here with a sable fur piece around my neck and my feet in a bearskin sack and I am still shivering with cold and can barely hold the pen. Never in my life have I seen a winter such as this one."

In more humble homes, people went to bed and woke to find their nightcaps frozen to the bed-head. Bread froze so hard it took an axe to cut it. According to a canon from Beaune in Burgundy, "travellers died in the countryside, livestock in the stables, wild animals in the woods; nearly all the birds died, wine froze in barrels and public fires were lit to warm the poor". From all over the country came reports of people found frozen to death. And with roads and rivers blocked by snow and ice, it was impossible to transport food to the cities. Paris waited three months for fresh supplies.

People went to bed and woke to find their nightcaps frozen to the bed-head
There was worse to come. Everywhere, fruit, nut and olive trees died. The winter wheat crop was destroyed. When spring finally arrived, the cold was replaced by worsening food shortages. In Paris, many survived only because the authorities, fearing an uprising, forced the rich to provide soup kitchens. With no grain to make bread, some country people made "flour" by grinding ferns, bulking out their loaves with nettles and thistles. By the summer, there were reports of starving people in the fields "eating grass like sheep". Before the year was out more than a million had died from cold or starvation.

The fact that so many people left accounts of the freeze suggests the winter of 1708/1709 was unusually bad, but just how extraordinary was it?
In 2004, Jürg Luterbacher, a climatologist at the University of Bern in Switzerland, produced a month-by-month reconstruction of Europe's climate since 1500, using a combination of direct measurements, proxy indicators of temperature such as tree rings and ice cores, and data gleaned from historical documents (Science, vol 303, p 1499). The winter of 1708-1709 was the coldest. Across large parts of Europe the temperature was as much as 7 °C below the average for 20th-century Europe.
Why it was quite so cold is harder to explain. The Little Ice Age was at its climax and Europe was experiencing climatically turbulent times: the 1690s saw a string of cold summers and failed harvests, while the summer of 1707 was so hot people died from heat exhaustion. Overall, the climate was colder, with the sun's output at its lowest for millennia. There were some spectacular volcanic eruptions in 1707 and 1708, including Mount Fuji in Japan and Santorini and Vesuvius in Europe. These would have sent dust high into the atmosphere, forming a veil over Europe. Such dust veils normally lead to cooler summers and sometimes warmer winters, but climatologists think that during this persistent cold phase, dust may have depressed both summer and winter temperatures.

None of these things accounts for the extremity of that particular winter, however. "Something unusual seems to have been happening," says Dennis Wheeler, a climatologist at the University of Sunderland, UK. As part of the
European Union's Millennium Project, which aims to reconstruct the past 1000 years of Europe's climate, Wheeler is extracting data from Royal Navy logbooks, which provide daily observations of wind and weather. "With daily data you can produce very reliable monthly averages but you can also see what happened from one day to the next," says Wheeler. He and his colleagues have now compiled a database of daily observations stretching back to 1685 from the English Channel area. "This is a key climatic zone. The weather there reflects wider conditions across the Atlantic, which is where in normal circumstances much European weather originates."

The most immediate cause of cold winters in Europe is usually an icy wind from Siberia. "What you would expect would be long runs of easterly winds with a well-developed anticyclone over Scandinavia sucking in cold air from Siberia," says Wheeler. Instead, his data show a predominance of southerly and westerly winds - which would normally bring warm air to Europe. "There were only occasional northerlies and easterlies and those were never for more than a few days," says Wheeler. Another odd finding was that January was unusually stormy. Winter storms tend to bring milder, if wilder, weather to Europe. "This combination of cold, storms and westerlies suggests some other mechanism was responsible for that winter."

There may be no easy explanation for the Great Frost of 1709, but unexpected weather patterns revealed by Wheeler's data underline
why climate reconstructions are so important. "We need to explain the natural variation in climate over past centuries so that we can tease apart all those factors that contribute to climate change. But before we can do that we need to nail down those changes in detail," says Wheeler. "Climate doesn't behave consistently and warmer and colder, drier and wetter periods can't always be explained by the same mechanisms." In the two decades after that terrible winter, the climate warmed very rapidly. "Some people point to that and say today's warming is nothing new. But they are not comparable. The factors causing warming then were quite different from those operating now."

Friday, January 9, 2009

Yellowstone Trembles

This is really not much to get excited about as yet, but the knowledge of this supervolcano’s potential has geologists paying attention. At least they are measuring what is important. The floor of the Caldera has lifted a foot or so over the past three years or so. This is pretty sedate and is likely to end with a small eruption.

When Mt St. Helens blew in the early eighties, no one appeared to understand simple physics, and crowded around the pending event as if it were slightly predictable. One of the last reports before the eruption stated that the mountain was rising up at a rate of several feet per day.

Anyone with a minimal grasp of physics knows that this means that if you multiply six feet of lift with a cubic mile or so of rock that you have massive amount of potential energy. I hope someone has put that problem into high school texts.

When that potential energy is converted to kinetic energy, you are at ground zero of an atomic bomb release. I heard that report and immediately wondered why anyone was within even twenty to thirty miles. It already was committed to a one way trip.

I do not know the dimensions of the caldera, but if the floor has lifted a foot we already have a plenty of potential energy been built up. The smart thing would be to map out 240 cubic miles of caldera rock and then estimate the buildup of potential energy. It may need to add 100 cubic miles of rock before the potential can be achieved. That means that we may really have a few 100,000 years before we get too concerned.

The same cannot be said for Mt Baker outside of Vancouver. It is fully rebuilt and when she decides to go hot, the probability of a major blast will be excellent if not almost certain. Fortunately the prevailing winds blow away from Vancouver which will minimize the impact. Mt Fuji is no better of course as is any well built perfect 10,000 foot volcano. None of them are really dormant either.

From The Times

January 5, 2009

Fears over earthquake 'swarm' at Yellowstone National Park

(William Kronholm/AP)

Yellowstone National Park: the most devastating earthquake hit August 17, 1959, which measured 7.1
Mike Harvey in San Francisco

Hundreds of earthquakes have hit Yellowstone National Park, raising fears of a more powerful volcanic eruption.

The earthquake swarm, the biggest in more than 20 years, is being closely monitored by scientists and emergency authorities.

The series of small quakes included three last Friday which measured stronger than magnitude 3.0. The strongest since this latest swarm of quakes began on December 27 was 3.9.

No damage has yet been reported but scientists say this level of activity - there have been more than 500 tremors in the last week - is highly unusual.

"The earthquake sequence is the most intense in this area for some years," said the Yellowstone Volcano Observatory. Some of the larger earthquakes have been felt by park employees and guests, according to the observatory.

The swarm is occurring beneath the northern part of Yellowstone Lake in the park. Yellowstone sits on the caldera of an ancient supervolcano and continuing geothermal activity can be seen in the picturesque geysers and steam holes, such as Old Faithful.

About 1,000 to 2,000 tremors a year have been recorded since 2004. The most devastating earthquake in recent history in the Yellowstone region occurred on August 17, 1959, when a magnitude 7.1 earthquake hit.

It was centered near Hebgen Lake, Montana and it caused landslides that killed 28 people and caused more than $11 million in damage.

Geysers in Yellowstone National park changed eruption times, and new ones began to erupt. On June 30, 1975, a magnitude 6.4 tremor hit the park.

Professor Robert B. Smith, a geophysicist at the University of Utah and one of the leading experts on earthquake and volcanic activity at Yellowstone, said that the swarm was significant.

"It's not business as usual," he said. "This is a large earthquake swarm, and we've recorded several hundred. We are paying careful attention. This is an important sequence."

The last full-scale explosion of the Yellowstone Supervolcano, the Lava Creek eruption which happened approximately 640,000 years ago, ejected about 240 cubic miles of rock and dust into the sky.

Geologists have been closely monitoring the rise and fall of the Yellowstone Plateau as an indication of changes in magma chamber pressure.

The Yellowstone caldera floor has risen recently - almost 3in per year for the past three years - a rate more than three times greater than ever observed since such measurements began in 1923.

From mid-summer 2004 through to mid-summer 2008, the land surface within the caldera moved upwards as much as 8in at the White Lake GPS station. The last major earthquake swarm was in 1985 and lasted three months.

The observatory said similar swarms have occurred in the past without triggering steam explosions or volcanic activity. However, the observatory said there is some potential for explosions and that earthquakes may continue and increase in intensity.

Joe Moore, director of the Wyoming Office of Homeland Security, said his office is tracking the events at Yellowstone on a minute-by-minute basis. "It's being followed very closely," Mr Moore said