(From PhysOrg.com h/t to Leif Svalgaard) — The recent warming trend in the Atlantic Ocean is largely due to reductions in airborne dust and volcanic emissions during the past 30 years, according to a new study.
A new study by UW-Madison researcher Amato Evan shows that variability of African dust storms and tropical volcanic eruptions can account for 70 percent of the warming North Atlantic Ocean temperatures observed during the past three decades. Since warmer water is a key ingredient in hurricane formation and intensity, dust and other airborne particles will play a critical role in developing a better understanding of these storms in a changing climate.
Since 1980, the tropical North Atlantic has been warming by an average of a quarter-degree Celsius (a half-degree Fahrenheit) per decade. Though this number sounds small, it can translate to big impacts on hurricanes, which thrive on warmer water, says Amato Evan, a researcher with the University of Wisconsin-Madison’s Cooperative Institute for Meteorological Satellite Studies and lead author of the new study. For example, the ocean temperature difference between 1994, a quiet hurricane year, and 2005’s record-breaking year of storms, was just one degree Fahrenheit.
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, report Evan and his colleagues at UW-Madison and the National Oceanic and Atmospheric Administration in a new paper. Their findings will appear in an upcoming issue of the journal Science and publish online March 26.
Evan and his colleagues have 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, they combined satellite data of dust and other particles with existing climate models to evaluate the effect on ocean temperature. They calculated how much of the Atlantic warming observed during the last 26 years can be accounted for by concurrent 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.
In fact, it is a surprisingly large amount, Evan says. “A lot of this upward trend in the long-term pattern can be explained just by dust storms and volcanoes,” he says. “About 70 percent of it is just being forced by the combination of dust and volcanoes, and about a quarter of it is just from the dust storms themselves.”
The result suggests that only about 30 percent of the observed Atlantic temperature increases are due to other factors, such as a warming climate. While not discounting the importance of global warming, Evan says this adjustment brings the estimate of global warming impact on Atlantic more into line with the smaller degree of ocean warming seen elsewhere, such as the Pacific.
“This makes sense, because we don’t really expect global warming to make the ocean [temperature] increase that fast,” he says.
Volcanoes are naturally unpredictable and thus difficult to include in climate models, Evan says, but newer climate models will need to include dust storms as a factor to accurately predict how ocean temperatures will change.
“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,” he says.
Satellite research of dust-storm activity is relatively young, and no one yet understands what drives dust variability from year to year. However, the fundamental role of the temperature of the tropical North Atlantic in hurricane formation and intensity means that this element will be critical to developing a better understanding of how the climate and storm patterns may change.
“Volcanoes and dust storms are really important if you want to understand changes over long periods of time,” Evan says. “If they have a huge effect on ocean temperature, they’re likely going to have a huge effect on hurricane variability as well.”
Source: University of Wisconsin-Madison (news : web)
Re: cobra (03:56:20) :
“Isn’t the red river flooding because of record snowfall?”
Exactly
“Since 1980, the tropical North Atlantic has been warming by an average of a quarter-degree Celsius (a half-degree Fahrenheit) per decade. Though this number sounds small, it can translate to big impacts on hurricanes, which thrive on warmer water, says Amato Evan, a researcher with the University of Wisconsin-Madison’s Cooperative Institute for Meteorological Satellite Studies and lead author of the new study. For example, the ocean temperature difference between 1994, a quiet hurricane year, and 2005’s record-breaking year of storms, was just one degree Fahrenheit.”
First: confession: I know nothing scientific about this.
Having said that, it seems incredible that the difference between normal and disaster is one degree F. No other natural phenomenon or event that I know of is that sensitive to small changes. It seems unnatural, if I might use that word, that this one issue hinges on such a small change. It leads me to think that maybe, just maybe, the science of hurricanes is more complex with other, perhaps more significant dependencies than a small rise in temperature. Was perhaps the rise in temperature in the hurricane zone much greater, and the 1 degree increase global? Like, you know, a lot hotter in the hurricane zone. If not, well…..
Superb satellite image that would have made Marcel Leroux proud…
A lack of dust may indeed eventually allow more of the Sun’s heat to do its thing along the equator. The dust has to be cleared out, which may take a while for the trade winds to use up the energy from rising hot air and the land has been scrubbed of the dander that had built up over the last 30 to 60 years of the warm, wet growing cycle. Eventually, the influx of north and south cold air gets all used up as the cycle’s energy dies down. Now cleared of reflective dust, the Sun begins to once again beam all of its heat down on the equator, building warmth into the sea surface and moisture in the air, causing the greening of the planet, but eventually restarting the next cold, dry, windy period when the heated surface finally breaks away from terra firma and begins to rise with increasing force. The land, once green and lush, begins to dry and whither from the cold dry wind, turning decades of vegetation and rain eroded dirt and silt into dry dust. The lands and the oceans, locked in a school yard game of seesaw.
Paul Schnurr (05:57:44),
Astonishing article. If an enemy nation tried to do what’s in that report, it would be an act of war. The fact that the West actually pays the UN for those suicidal proposals is inexplicable. The best possible course of action would be to completely cut off the UN’s income and evict them from civilized countries.
I can imagine, that locally, this decadal osillation of dust can be interruped by dry season irrigation, keeping the land always green, which prevents the wind from picking up the dry bare-ground soil and carrying it out to sea to feed the marine life. Growing populations should eventually use up what was once irrigation water, leading us back to the natural oscillation.
I wonder how much of the remaining 30% is due to the Clean Air Act that was passed in the 70’s and cut down on the aerosols that were causing the acid rain in the eastern U.S. before they drifted out over the North Atlantic.
In a White House interview with a handful of reporters, including Janell Cole of the Forum of Fargo, the president said the current flooding cannot necessarily be blamed on global warming, but he said it should be a signal to act.
Dear Mr. Obama,
My cat just took a crap in her litterbox. Please let me know if this is a signal to act on global warming.
Squidly (20:28:16) :
“Sorry to be a little off topic, but I just couldn’t hold back. Our commander in chief is already laying the BS (bad science) on thick. Obama: Red River flooding is wakeup call to fight global warming. President Obama used the flooding in the Red River Valley to insist that society needs to take global warming seriously.”
CodeTech (23:05:53) :
“Squidly: As long as I can remember, the Red River has been flooding. I myself took several pictures of Winnipeg from the air showing what an incredible river it is, and how insane it is to build around it.”
I have the solution. Offered it before when a record(?) amount of snow was reported for No Dakota. Transport the “excess” to California and the dryer parts of the West/Southwest. This is an intelligent solution that a natural-born-American President might consider. As I understand it, the Red River Valley drains into Hudson Bay. Ice melts later in the north, in Manitoba, Canada; therefore, there is nowhere for the water to go except to fill up the basin/flood plain. Build pipes, canals, send it along the railways. I think Roger Sowell had a plan. Do something sensible, along with ending U.S. dependence on Middle East Oil by developing domestic fossil fuel resources (Janet Levy, American Thinker).
The “Dust Study” should put another knife in the vampiric heart of cap-and-trade.
* Al Gore, Chairman of the Board, Alliance for Climate Protection
* Nuke the land, not the people. People don’t produce nearly enough dust.
* That article completely ignored that the experiment was a success by increasing the growth of ocean life, which did indeed remove more carbon from the atmosphere. And additional carbon will be sequestered in the form of fish feces and shrimp shells.
Snowfall, the recent rain on the floodwaters, and the northerly flow of the river. Even if global warming warms the poles a little, the river will still freeze in the winter and the southern part will still thaw before the north mouth of the river. We could fix that with enough excavation to reverse the direction of flow of the river and make all that water flow into the Mississippi, but that would create new problems.
Reading over this study it appears to be yet another case of an observed correlation taken to mean causality.
SAHEL and volcanic dust is important to climate (and weather in the form of Hurricanes) for sure, but I doubt it is the main factor in the Atlantic. There is good physics behind the idea that Tropical Atlantic (and entire Atlantic for that matter) SST variability is driven largely by the AMO and other internal modes of oceanic variability.
This study study again proved the effect of particulate pollution has been under estimated. It is far more powerful than GHGs.
I think high altitude particulate pollution cools the atmosphere and low altitude particulate pollution warms the atmosphere. Both high and low altitude particulate pollution cool the ocean surface due to the dimming effect. The atmosphere cooled from the 40s until the 70s. During this period world war II and above ground testing of nuclear weapons increased high high level particulate pollution. When above ground testing of nuclear weapons was banned in the 70s global warming began.
Seems like UW-Madison is on the semi-skeptic side of things…
…while UW-Seattle is on the believer side.
Hmm.
“If you look at the flooding that’s going on right now in North Dakota and you say to yourself, ‘If you see an increase of 2 degrees, what does that do, in terms of the situation there?’ ”
Agreed, BS as in boeotian science. Our Popinjay Prez knows his climate science, his macroeconomics, his labor relations, his multinational diplomacy, his vetting subordinates, his constitutional law, etc., all equally well. Not worth spit.
Doesn’t seem to be eroding Presidential powers though, like FISA. Small comfort.
“Seems like UW-Madison is on the semi-skeptic side of things”
Mad City sanity, how oxymoronic. Always been a good grad school though- activist bomb target of merit.
“Since 1980, the tropical North Atlantic has been warming by an average of a quarter-degree Celsius (a half-degree Fahrenheit) per decade.”
“the ocean temperature difference between 1994, a quiet hurricane year, and 2005’s record-breaking year of storms, was just one degree Fahrenheit.”
Therefore, between 1980 and 1994, the Atlantic bearly warmed at all?
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AnonyMoose (07:07:13) :
Al Gore is set to release his second book on climate change … All of the proceeds from the book will go to The Alliance for Climate Protection …
* Al Gore, Chairman of the Board, Alliance for Climate Protection
Excellent find Moose.
Ric Werme (05:44:42) :
I’m not sure if you’re referring to colder weather globally or colder weather reaching a tropical storm.
I meant colder weather in general over the ocean, which is what this dust study suggests. I linked originally to the fact that warmer weather causes more wind shear destruction of hurricanes, and then this is out, which says that hurricanes are toasted by cooling. Seems like there is a whole lot unknown about hurricanes.
Perhaps we have a link between CO2 and Atlantic hurricanes. If increassed hurricane activities come from warmer ocean temperatures, and if warmer ocean temperatures are due to less dust, and less dust is due to a greener Sahara, and a greener Sahara is due to increased levels of CO2, we now have a link between CO2 and Atlantic hurricanes.
When I was a young catholic girl, fresh from first communion, I wanted to do everything right in confession and then receive communion. So to do that, I had to make up lies to tell in confession because how much mischief can a girl of 7 get into? To wit, I killed my brother, my grandmother, robbed a bank, and said dirty words, all confessed to a very patient family friend who knew where I was and what I was doing 24-7. He patiently forgave me and for my penance told me to say 3 hail mary’s and one our father. Then with a poker face that must have killed him to keep steady, he gave me communion.
So for those of us who lie like a drunken sailor about whatever on this blog, you are forgiven. Say 3 hail mary’s and one our father.
Been to Gran Canaria for the last three years running ( one of the islands on the NASA shot). The year it was clear the temps were 3 to 4 c higher easily maybe more, When sand storms driffted over it was much cooler— but this is only the same as on a bright sunny summers day to a cloudy one
Sometimes it is a good idea to step back and take a longer look at weather patterns, and just see where climate begins. In order to get a reasonable long term perspective on temperature, we went to the longest continual data recordings, put out by the Hadley Center, and available at Climate4You, http://www.climate4you.com, where they also have some very good plots.
Go to the Global Temp tab, download the data into a spreadsheet, EXCEL. The data includes year, monthly averages and yearly average. Next two columns were added, one for a linear function T_est = b + m (yr_x – 1659), and yearly error [ER]. Tried to use the least square linear function supplied with EXCEL, but it “choked up”, so I computed the linear estimation column using to “fixed” parameters b & m. The error was summed to aid in adjusting b and m. A plot was then made of year vs. temperature error. After a few minutes, manually adjusting b and m, to minimize the summed error, a close match was found with the following equation: T_est = 8.85 + 0.002 * ( YEAR – 1659), with a summed error of ~5 deg. A second “smoothed curve” was added, using a 1st order recursive filter x = x_1 + 0.25*(ER) highlighted the short term trends. With a slope of about 2 deg. per century, doesn’t look like much has changed.
Now while this is one sample point on the globe. If I were a gambling man, I don’t think I’d bet the farm on global warming.
According to the ‘New Scientist’ magazine the Hockey Stick graph has been re-validated! So, it is our fault, after all.
http://www.newscientist.com/article/mg20127011.500-arctic-meltdown-is-a-threat-to-humanity.html
So sorry, wrong link in the last post!
http://www.newscientist.com/article/dn11637