North Atlantic was Cooled by African Dust
Satellite view of dust moving off the coast of western Africa

Evidence from the MODIS instrument on NASA satellites has determined that it was indeed Saharan dust that was responsible for one-third of the drop in North Atlantic sea surface between June 2005 and 2006. This drop in sea surface temperature may have contributed to the difference in hurricane activity between the two seasons. There were 15 hurricanes in the Atlantic Basin in 2005, but only 5 in 2006 as the sea surface temperatures remained relatively cool. By the way, this past season also saw less activity than what was earlier predicted.
Satellite view of Saharan Dust covering the Caribbean

According to the study by William Lau and Kyu-Myong Kim from NASA's Goddard Space Flight Center, the dust effectively blocked sunlight from reaching the sun's surface and accounted for a 30-40% drop in temperature during the period. The actual drop in the North Atlantic was between 0.37 and 0.72 degrees F., or one-third of the total sea surface cooling of the North Atlantic.
"Previous studies have looked at how hot, dry air associated with a Saharan dust outbreak affects an individual storm, but our study is the first to focus on dust's radiative effect on sea surface temperatures, which may affect storms for the entire season. Nobody had suggested that link before," Lau says.
Scientists are also studying a possible link between the African dust and a high incidence of respiratory diseases and bronchial asthma on the island of Cuba.







Comments (22)
Hmmmm...I wonder how they figured the percent change is what they say it is? Also, makes one wonder if all of the pollution controls implemented in the past are not now contributing to the warming more so than GHGs. Not saying I want polluted air by any means but this dust theory makes you think that cleaner air leads to more heat uptake.
Posted by Darren | December 19, 2007 9:47 AM
Another hashmark to add to the negative Feedback column we didn't know about before.
Posted by Dave | December 19, 2007 11:09 AM
This is exactly what the accuweather hurricane center was reporting all summer.
Another indication of how complex the climate is, and how difficult it is to model a chaotic system.
Posted by Patrick Henry | December 19, 2007 11:11 AM
Interesting ........it's nice to see that some science professionals are looking at something other than CO2 which affect weather/climate/planet.
Looks like the model builders will have to "adjust" their results to reflect reality once again!
Kinda reminds me of the predictions of Nostradomus. There's always a way to show his predictions were accurate "after the fact". His "secret code" permits followers to justify anything and everything in hindsight .....
http://en.wikipedia.org/wiki/Hindsight_bias
Looks like climate's equivalent to the "secret code" is CO2.
Just can't wait to see how they spin the next 5 years results ......
Posted by PaulB | December 19, 2007 11:51 AM
A very interesting article.
"......is the first to focus on dust's radiative effect on sea surface temperatures, which may affect storms for the entire season. Nobody had suggested that link before," Lau says.
One would think that if dust affects a single storm because of temperature drop, then lots of dust over an entire season may affect ocean temperature too.
Holmes would say, “Elementary my dear Watson!"
Yet have NEVER been done. So seemingly elementary concepts on how the world works are simply missed, ignored or just not thought of. I would offer that there are a lot of obvious mechanisms that have not been thought of much less studied in this fledgling study of the natural world called “Climate Science”. This statement shows just how young and inexperienced Climate "science" actually is. They are trying to fly and proclaim an Apocalypse when they need to learn to sit up first. Yet the AGW pundits proclaim that 5 models on their PC gives them the answer. That arrogance is the very definition of hubris.
“We have figured in all we know !” is proclaimed! True except this is not about what you know. It’s about what is needed to know before trillions of dollars and millions of people are displaced and inconvenienced. What part about “We really don’t know much about how the real world actually works” do we fail to grasp?
The AGW religious left will never understand the concept that we just don’t have enough information to make a rational decision based on science fact. To those on the fence actually trying to understand if AGW is actually a problem much less can we fix it, I say read, learn and think for yourselves. The science as presented is so incomplete, skewed, contradictory, and just plain confusing that it may be better to do nothing than run around like Chicken Little screaming the Sky is falling.
If we think the earth is sick and needs help, let’s make sure we use the right prescription. An old guy once gave advice and it has stood the challenge of time: Remember “First! Do no harm!”
Posted by ted | December 19, 2007 12:03 PM
How does dust from Africa keep the sunlight from reaching the sun's surface?.....
Posted by mg | December 19, 2007 12:49 PM
Ted: It's hard to know if your rant falls under the 1st stage of the deniers creed, The earth is not warming, or the fifth stage, If it's bad there's nothing you can do about it. Saying that we can't take action because we don't know enough is one of the oldest dodges in the denial game. It was used to great affect by the tobacco industry, the asbestos industry, the chemical industry (remember Love Canal?) and many others. Actually we know a great deal about the way the climate works on our planet and we are learning more and more each day. And all of the little pieces are dropping into place and telling us that the planet is in peril.
And, Patrick Henry, the very reason that we have modeling is to better understand "chaotic systems". Do you really believe we should study nothing, understand nothing and, when we come to some understanding, do nothing? what an odd philosophy.
Posted by kevinag | December 19, 2007 2:04 PM
Saharan dust that was responsible for one-third of the drop in North Atlantic sea surface between June 2005 and 2006.
Quick IQ quiz for Pete, Mark, BT and Boris
The other two-thirds of the 2006 North Atlantic drop were caused by
A. Low atmospheric CO2
B. Low solar activity
C. Hansen's "Super El Nino"
D. Aliens
Posted by Patrick Henry | December 19, 2007 2:28 PM
What does pollution have to do with African dust?
Maybe the dust was caused by Iran testing their nuclear weapons out in Africa. Quick, we must invade them now! LOL
Posted by Mark | December 19, 2007 2:39 PM
Patrick Henry,
How about
E. Inter-seasonal Variation
?
Posted by cbmclean | December 19, 2007 3:46 PM
Mark:
Good point, had not put that together yet. That theory is much more concerning than the theory of AGW. And, for that matter, more of a threat to the world in the near future than what several degrees of "abnormal" warming might be.
kevinag:
Ah yes, the denier's creed, how elegant. Really the scientists of the world do know a lot about our climate, but in the end analyis, not enough to know if there truly is a problem. As I alluded to initially, could there be a positive feedback in that removing particulates from the air has lead to the observance of higher temps? Or is it a big coincidence? Simply put, there has been no piece drop into place that would state that the world as a whole is in peril.
Posted by Darren | December 19, 2007 4:26 PM
Kevinag,
First of all I am a skeptic not a denier. It’s is nice to know you read my post. Your reaction is interesting as it denotes a deep visceral feeling of frustration and anger. I am sorry if I don’t jump on the bandwagon. I find the basic deep flaws in the AGW theory (and that is all it is) never seem to be answered. In my professional life that has always been a signal for caution no matter how many sing its praises.
Secondly: Your ranting on the subjects of smoking and asbestos has nothing to do with what I wrote nor is it applicable for use as simile.
Obviously your reaction is from my asking people to think for themselves and question the gospel of AGW. Apparently that is from a fundamental fear that knowledge is bad for people when others know what is best for everyone. That is a truly frightening prospect for science, rational thought and the human race.
The more the AGW side fails to use science and logic and instead attacks those that question, it shows bad form and fear of the truth. I would say that skepticism is indeed called for.
Climate science is young and doesn’t have all the answers. There are more questions than answers and instead of embracing those asking they circle the proverbial wagons and start shooting. If this was a person instead of a semi-religion one could diagnose “Feelings of inadequacy mixed with delusions of grandeur.”
Folks read, learn, question, and then think for yourselves. Don’t convert unless you are convinced that AGW is real. Remember bad math, poor or questionable science, questions answered by attacking the motives of those asking, and problematic “peer review articles” all say "more questions need to be asked."
Posted by ted | December 19, 2007 5:23 PM
This is only my 2nd post, I came in knowing very little about AGW. I thought it was true, I believed it because I only had such a skin deep knowledge. I had seen head lines and had heard about Al Gore's movie (never saw it though)
I have been checking these thread for about a month or so now, and I have clicked on many links, and browsed many graphs and scientific facts, and I have concluded personally, that AGW does not exist. Also, I have found the typical
"stat trap" from both sides. For every stat you can throw out, heavily reference by credentialed people, there is a stat that woudl refute your point by a just as seemingly credible reference. Furthermore, you can create a stat to prove a point very easily. Stats can be biased, because the tests proving them were typically set up by some one who already had their opinion. If you ask me stats are useless for the most part. You want a conlcusion from a stat? If we look at the number of drowning deaths in the USA and compare it to the amount of ice cream eaten in the USA, we can conclude that, the more ice cream we eat, the more drownings occur. So if we decrease the amount of ice cream we eat, the drowning deaths should go down, so we should cease production of ice cream immediately, right?
Posted by Veets | December 19, 2007 5:34 PM
kevinag,
Study is wonderful.
Driving the world to panic claiming you know things you don't, is immoral and illegal. It is the equivalent of yelling fire in a crowded theater.
Posted by Patrick Henry | December 19, 2007 6:36 PM
Veets, the ice cream analogy was great!
Posted by saly | December 19, 2007 7:36 PM
Veets,
You keep reading, asking questions and think for yourself.
Your decision may be right or wrong but you used your brain and didn't blindly take the word of somebody else.
That is power in itself! That's all anybody can ask for.
Posted by ted | December 20, 2007 12:57 PM
Ted: I went back to your original post to see if I had miscast it as a rant. I had not. I went back to my response to see if it showed "obvious signs of it denotes a deep visceral feeling of frustration and anger." It did not. My points about the tobacco, asbestos and chemical industries where to the point; that being statements that we can not act because of all that we don't know. If that were the case we would never be required to act because we could always say we do not know enough. Your attempts to belittle my beliefs by implying that they are part of some semi religious cult are an abvious attempt to shame and silence me. I have no �Feelings of inadequacy mixed with delusions of grandeur.� I would ascert that it is the deniers who often "fail to use science and logic" and, instead attack the motives of those of us concerned with our world and its future. No one that I know in this movement is concerned with money, power or self aggrandizement. To continually imply that we are is a falsehood and needs to be addressed whenever it is uttered.
As for Patrick Henry's comment: "Driving the world to panic claiming you know things you don't, is immoral and illegal. It is the equivalent of yelling fire in a crowded theater." It is immoral and illegal only if there is no fire. If there is a fire, then the shouter becomes a hero! As for Veet; Ihope you continue to question and look for answers. And I hope you look for information on other sites besides this one! As for the drowning and ice cream argument, I am glad I never tried that one on my debate teachers, I'd still be feeling their rath!! And finally let me say that I will from this point on confine my reading of this blog to the main story and leave the comments page to youall. There seems little reason to continue to subject my "frustrated and angry" psyche to more obfuscation and abuse. Adios and good luck.
Posted by kevinag | December 20, 2007 3:04 PM
PH, apparently human activity is unnatural. So with that I pick D, aliens. Where is BT anyway, shoveling snow?
Veets, good for you!
Mark, Mark, Mark. Atleast you are keeping an eye on Iran, which is good to see. Keep watching. Did you notice Russias involvement as foretold by moi? Turmoil will inevitably escalate in the middle east. Israel will be strategically dropping bombs on Iran sooner rather than later. That will certainly infuriate Russia and an Arab federation, dont ya think? You believe gas prices are high now?
But hey, lets keep believing that we can control the climate and ignore a growing middle-eastern threat, ok?
Posted by RICH | December 20, 2007 3:25 PM
kevinag, please don't leave, your ramblings make me laugh.....
Posted by Freddy | December 20, 2007 4:14 PM
freddy: Thank you for making the case for me. It is a brave man that hides behind the anonymity of the internet and taunts someone. But youall carry on and talk among yourselves. Who knows, maybe you do have God on your side!
Posted by kevinag | December 20, 2007 8:06 PM
Living in an Atlantic coastal area that was afflicted by a Red Tide event this Summer. The local weather types ascribed the Sahara dust as being the culprit for the Red Tide outbreak. Their theory is that the Sahara dust carries nutrients for the Red Tide organisims and they go wild upon getting the feeding.
Posted by mmi16 | December 23, 2007 12:56 AM
A 40% drop in temperature is approx 120K taking the temperature down to about -100 Celcius. Are you seriously saying this happened?
Posted by John Adlington | December 24, 2007 4:20 AM