(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)
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Re: data supporting AGW theory
“And another one gone, and another one gone
Another one bites the dust
Hey, Im gonna get you too
Another one bites the dust…”
Sorry, couldn’t resist…
For anyone interested, I wrote a post about the Tropical Atlantic SST anomalies back in September.
http://bobtisdale.blogspot.com/2008/09/tropical-sst-anomalies-revisited_24.html
Keep in mind, though, that the Evan et al study also deals with the temperature of the mixing layer. In the abstract I linked above, they mention surface AND mixing layer temperatures.
Re: Ohioholic (19:52:20) :
“Wasn’t there another study done that concluded that the wind shear over warmer water prevented hurricanes from forming as often?”
There are actually many studies in this area – well established physics.
Think of a Hurricane as a rotating cylinder that extends from the ocean surface to the top of the Troposphere. If the winds aloft are blowing with a different speed and/or direction to the winds near the surface, the cylinder (Hurricane) gets sheared apart. It is tough for a Hurricane to form or survive under high shear.
However, dust is another critical factor – quite often during Hurricane Season you will see areas of strong convection (thunderstorm activity) – prime candidates for genesis into a Tropical Cyclone – get quashed by these big plumes of dust blowing off the Sahara. This is known as the “Saharan Air Layer or SAL” – you can monitor SAL conditions here http://cimss.ssec.wisc.edu/tropic2/real-time/salmain.php?&prod=splitEW&time
A growing understanding of the complexity of this planet’s climate erodes the simplistic view of CO2 warmists. It is simply not possible to model climate to forecast change in the future, be it short or long term. Humanity can only monitor change, not control it.
Well, we can all rest easier now…
ArtsBeat is reporting that former vice president, and Oscar winner, Al Gore is set to release his second book on climate change this fall. This follows his critically acclaimed 2006 book and documentary An Inconvenient Truth, which came very close to stopping global warming, but fell a little bit short. The new book Our Choice, will attempt to finish the job by proposing environmental policies that reduce Carbon Dioxide while also improving our economy. All of the proceeds from the book will go to The Alliance for Climate Protection and the book will be printed on 100% recycled paper, so get down from those redwood trees, hippies.
mikef: You wrote, “but the Argo’s are trending down, Josh Willis is prob in an uncomefortable place right now, and will have to admit ocean cooling over the last few years?”
In the most recent paper on OHC, Levitus et al state, “Figure S11 shows time series of OHC700 for individual ocean basins as well as the world ocean. Both the Pacific and Atlantic oceans show decreases after 2005-06 whereas the Indian Ocean does not. The linear trend accounts for 89 and 85% of the variance in the Atlantic and world ocean respectively and 68 and 52% in the Pacific and Indian oceans respectively for the 1969-2008 period.”
A link to the paper:
ftp://ftp.nodc.noaa.gov/pub/data.nodc/woa/PUBLICATIONS/grlheat08.pdf
Note that the trends in the illustrations are for the period of 1968 to 2008, not the entire dataset, which starts in 1955.
I did a quick post on it the Levitus OHC paper, but only looked at the global data. Here’s a link:
http://bobtisdale.blogspot.com/2009/03/latest-revisions-to-ocean-heat-content.html
although it won’t get much play, the entire Caribbean and most of the hurricane MDR (main development region) are showing below normal SST anomalies this year. it will be interesting to see how these change in the next couple of months, but I don’t recall this being the case the last 4-5 years.
http://www.osdpd.noaa.gov/PSB/EPS/SST/data/anomwnc.gif
Ric Werme (20:50:49) :
“…Dust acts two ways. First is the solar dimming mentioned above that leads to lower SSTs. Second is the sunlight blocked by dust warms the atomosphere reducing convection of surface level air. Dust has the biggest impact on the Cape Vered hurricanes that form of the African coast and have the longest fetch where they can intensify.”
Well…OK but there is a third, much larger issue. The dusty air blowing off Africa into the Atlantic is very *DRY* and warm. For tropical waves-hurricanes to form, they need deep moisture and convective instability. Both are missing in the dry continental air.
I think this whole paper is bogus. Didn’t Dr. William Grey attribute the warming in the Atlantic to the AMO (Atlantic Multi-decidal Oscillation)? Yes, it has been warming for the past 20-30 years & now it is starting to cool. I have a real hard time believeing the warming over the past 20 years has been because of dust off of a desert which has been there for a *whole* lot longer than that!
Just my $.02
Jeff
Re: Squidly (20:28:16) :
Most of the top 80 ft or so of the eastern half of North Dakota is either 1) Lake Sediment (from a paleo lake known as “Lake Agassiz”) or 2) River and beach sediment from the paleo Red River, the next 100 ft down and you pass through mostly Glacial deposits from the Pleistocene, then you hit bedrock.
See http://www.ndsu.nodak.edu/ndsu/nd_geology/nd_maps/nd_map4.jpg
and
http://www.ndsu.edu/instruct/schwert/fargo/xsection.htm
I don’t think cavemen were driving SUVs back in the late Pleistocene (they most certainly did not have coal-fired power stations)…
Well, I was going to mention the false comparisons, illogical assumptions, etc. But from now on I will jsut post this standard response:
In his Fiscal Year 2010 budget, Obama said he planned to raise $646 billion from 2012 to 2019 in climate revenues by auctioning off emission credits in a system that capped greenhouse gas levels and created a market to buy and sell emission allowances. Treasury officials say the actual revenues could actually double or triple that amount.
I think we can safely say the science is settled. Move on.
” 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.”
You never hear one word about building codes and building permits when houses are flooded.
Bureaucrats, politicians and their propagandists always find something else to blame.
Volcanoes are naturally unpredictable and thus difficult to include in climate models, Evan says
Yet another thing climate models don’t take in to account correctly. Yet more evidence that you cannot model a chaotic system.
to barry l.
there are articles that suggest the changing frictions of the earths atmosphere moving against the earth due to changing speed of the earths rotation cause changes in volcanic activity by causing extrat riction or causing fault lines to move etc.
( earths rortation varies according to tilt, and solar intensity plus other solar factors).
i think this is what r bateman means above. if i find the article i will post it….. ( there is more than one and it is in the article i mentioned above i think).
Isn’t the red river flooding because of record snowfall?
This ocean warming explains the rapid raise in central england temperatures (CET) in the last 30 years, which is about the same order of magnitude. Do dust records exist for the past? The last big run-up the CET temperatures was from 1700 to 1730.
Fascinating how a paper on a Tropical North Atlantic phenomenon becomes first North Atlantic, and then just Atlantic temperatures, no?
Maybe the ND floods should have a thread of it’s own, but as far as I know a warming climate in the area would actually reduce the liklihood of flooding due to more snow melting over the winter months instead of all at once during a late winter thaw.
“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.”
How simplistically wrong.
The post by hswiseman (20:19:24) is correct.
The best example of cherry picking data I have ever seen : “the ocean temperature difference between 1994, a quiet hurricane year, and 2005’s record-breaking year of storms, was just one degree Fahrenheit.”
Perhaps we could have annual “Cherry Pickin’ Data Awards”. The nominations alone would be interesting.
“Robert Bateman (20:07:52) :
…Rock holds back the magma, and if it cools only a bit, it’s brittleness increases”
Rock, magma, scissors?
Couldn’t resist.
JimB
Once more climate models?, they put everything in them except the drivers all know, beginning with the old and faithful sun.
“God doesn´t play dice” (Albert Einstein)
“AnonyMoose (21:19:31) :
So the solution to this great threat of Arctic melting would be to nuke Africa. I’m sure that will be a great relief to many people.”
Might as well…we’re doing everything possible to keep them in stone-age conditions anyway in the name of saving the planet. One might ask exactly who’s planet we’re saving…certainly not Africa’s.
“Silver (22:51:20) :
Off topic (or maybe not):
“Hungry shrimp eat climate change experiment”
I thought my shrimp last night had a slightly metallic flavor.
JimB
Squidly (20:28:16) :
Glenn (22:19:55) :
CodeTech (23:05:53) :
Re Obama and the Red River:
The weather guy on Fox News Channel between 11 AM and noon (EDT) yesterday pointed out that (a) the temperatures were very cold, and (b) that there were ice dams in Manitoba that were impeding drainage from the flooded areas further south, so that it was likely that the river would remain at flood stage for up to two weeks.
President Obama clearly has no idea what he is saying; he is just reiterating (and garbling) talking points that others have fed him. But it is dismaying. My wife keeps saying, “We have to educate him!” But how can anyone get through the thick wall of willful ignorance (read dogma) this President has surrounded himself with?
This is why I keep saying we must find a prominent spokesman for the Realist side, who can take the lead in educating the public, the media, and the politicians. I wonder if Mitt Romney might be willing to take on that duty. . .
/Mr Lynn
@ur momisugly Squidly (20:28:16) :
The worst flood in the Fargo area was 1897. How does that fit into the AGW story?
Ohioholic (20:31:58) :
I’m not sure if you’re referring to colder weather globally or colder weather reaching a tropical storm. In the latter case, that’s generally a cold front and tropical storm coming together and hastens the transition from tropical storm (driven by convection) to extratropical storm (driven by horizontal temperature difference and upper atmosphere effects).
Another thing that impacts storm once they’ve formed is dry air entrainment. Watch the water vapor images next hurricane season, when a storm swallows a big chunk of dry air it cause major disruption to convection and can greatly weaken the storm within hours. Much more impressive than running into shear, which just blows off the storm tops, dry air hacks away at the knees.
OT from Drudge:
A United Nations document on “climate change” that will be distributed to a major environmental conclave next week envisions a huge reordering of the world economy, likely involving trillions of dollars in wealth transfer, millions of job losses and gains, new taxes, industrial relocations, new tariffs and subsidies, and complicated payments for greenhouse gas abatement schemes and carbon taxes — all under the supervision of the world body.