Where Have the Hurricanes Gone?

[Odin]

Originally posted by Drake Tungsten
A chart showing temperature changes over the last 100,000 years would be a lot more useful...

[Drake Tungsten]

So if current temperatures aren't any higher than temperatures during four other warm periods over the past 500,000 years and we seem to be roughly at a period where a natural rise in temperatures is to be expected, why exactly should we blame the current global warming trend on humans?

[Odin]

Originally posted by Drake Tungsten
So if current temperatures aren't any higher than temperatures during four other warm periods over the past 500,000 years and we seem to be roughly at a period where a natural rise in temperatures is to be expected, why exactly should we blame the current global warming trend on humans?

Because we're pumping CO2 into the atmosphere and CO2 is a greenhouse gas?

I see you've already forgot about this chart:

[Kuciwalker]

Originally posted by Odin
* Odin points to the last 100 years of the graph...

Anyone who thinks the warming in the last 100 years is in any way all or mostly natural is kidding themselves.

If you look at specifically the line with error bars, the past 100 years don't look particularly out of place.

[BlackCat]

Back on topic - Che, you might find this interesting since it apparently offers an explanation to why there are variations in the number of hurricanes knocking on your door :

http://www.physorg.com/news79721156.html

After more than a dozen hurricanes battered the Atlantic Ocean last year, scientists are wondering what — if anything — might be causing stronger and more frequent storms. Some have pointed to rising ocean temperatures, brought on by global warming. Others say the upswing is simply part of a natural cycle in which hurricanes get worse for a decade or two before dying down again.

Now, researchers at the University of Wisconsin-Madison have put forward an intriguing theory that introduces a whole new dimension to the debate.

Writing Oct. 11 in the journal Geophysical Research Letters, the scientists discuss a surprising link between hurricane frequency in the Atlantic and thick clouds of dust that periodically rise from the Sahara Desert and blow off Africa's western coast.

Lead author Amato Evan, a researcher at UW-Madison's Cooperative Institute for Meteorological Satellite Studies (CIMSS), pored over 25 years of satellite data — dating from 1981-2006 — and noticed the correlation. During periods of intense hurricane activity, he found, dust was relatively scarce in the atmosphere. In years when stronger dust storms rose up, on the other hand, fewer hurricanes swept through the Atlantic.

"These findings are important because they show that long-term changes in hurricanes may be related to many different factors," says co-author Jonathan Foley, director of UW-Madison's Center for Sustainability and the Global Environment. "While a great deal of work has focused on the links between [hurricanes] and warming ocean temperatures, this research adds another piece to the puzzle."

If scientists conclusively prove that dust storms help to squelch hurricanes, weather forecasters could one day begin to track atmospheric dust, factoring it into their predictions for the first time.

Researchers have increasingly turned their attention to the environmental impact of dust, after it became clear that in some years, many million tons of sand rise up from the Sahara Desert and float right across the Atlantic Ocean, sometimes in as few as five days.

"People didn't understand the potential impact of dust until satellites allowed us to see how incredibly expansive these dust storms can be," says Evan. "Sometimes during the summer, sunsets in Puerto Rico are beautiful because of all the dust in the sky. Well, that dust comes all the way from Africa."

The Sahara sand rises when hot desert air collides with the cooler, dryer air of the Sahel region — just south of the Sahara — and forms wind. As particles swirl upwards, strong trade winds begin to blow them west into the northern Atlantic. Dust storms form primarily during summer and winter months, but in some years — for reasons that aren't understood — they barely form at all.

Evan decided to explore the correlations between dust and hurricane activity after CIMSS research scientist Christopher Velden and others suggested that dust storms moving over the tropical North Atlantic might be able to suppress the development of hurricanes.

The UW-Madison researchers say that makes sense because dry, dust-ridden layers of air probably helps to "dampen" brewing hurricanes, which need heat and moisture to fuel them. That effect, Velden adds, could also mean that dust storms have the potential to shift a hurricane's direction further to the west, which unfortunately means it would have a higher chance of hitting U.S. land.

While the UW-Madison work doesn't confirm that dust storms directly influence hurricanes, it does provide compelling evidence that the two phenomena are linked in some way. "What we don't know is whether the dust affects the hurricanes directly, or whether both [dust and hurricanes] are responding to the same large scale atmospheric changes around the tropical Atlantic," says Foley. "That's what future research needs to find out."

Jason Dunion of the National Oceanic and Atmospheric Administration's Hurricane Research Division also contributed to the study.

Source: by Paroma Basu, University of Wisconsin-Madison

[Dinner]

As has already been pointed out to the dumb ass Hurricanes vary from year to year and El Nino years result in few hurricanes in the Atlantic. It is scientifically indisputable that the Earth is warming and that such warming results in more energy for hurricanes to take advantage of.

[chequita guevara]

Originally posted by The Mad Viking
We had several ice ages that lasted millions of years each. They ended, and glaciers melted at alarming rates. Not one human around. Who caused THAT global warming?

By that logic, there's no such thing as murder, because people die naturally on their own.

[chequita guevara]

Less hurricanes for me. More extra-tropical cyclones for Oerdin.

Speaking of extra-tropical cyclones, those types of storms are produced by lattitudinal temperature gradients in precisely the manner described by Berz.

[BlackCat]

Originally posted by Oerdin
As has already been pointed out to the dumb ass Hurricanes vary from year to year and El Nino years result in few hurricanes in the Atlantic. It is scientifically indisputable that the Earth is warming and that such warming results in more energy for hurricanes to take advantage of.

What are you talking about ? That study doesn't say a word about the temperature potential for creation of hurricanes. It discusses wether dust storms may have an impact on such creation.

It doesn't really matter that there is a link between El Nino and atlantic hurricanes - unless, of course, that you think that it automagically rules out anything else to maybe have an impact.

That study was published last week, so I guess that we should give some time for other researchers to check it and not just shoot it down on reflex.

[Berzerker]

The UW-Madison researchers say that makes sense because dry, dust-ridden layers of air probably helps to "dampen" brewing hurricanes, which need heat and moisture to fuel them.

It is my understanding hurricanes need moisture and heat at or just above sea level and cooler air up high to promote condensation at the right altitude as the moist warm air from below rises. If the air above is warmer, how does the moist warm air from below rise? So is it the dust that inhibits hurricane growth or is it the dry warm air mass blowing out over the Atlantic? When the winds dont blow, neither does the dust, and we get more hurricanes. When the winds blow and the dust flies, hurricane production declines. The dust is merely the evidence of strong winds coming off the continent, but a dust grain can also become the nucleus of a rain drop as h2o condenses in a dust cloud. So maybe both the warm dry Saharan winds and the dust effect hurricanes.

It is scientifically indisputable that the Earth is warming and that such warming results in more energy for hurricanes to take advantage of.

Hurricanes require energy, but they require temperature contrasts too, both within the structure and in the path of the storm. If the upper hurricane runs into warm air it dissipates, so we dont know if a warmer world results in more hurricanes. It may sound counter-intuitive but I suspect a warmer world means less severe atmospheric disturbances as the contrast between a warm equator and cool poles is reduced. If "the greenhouse effect" is to have meaning, then it also means greater stability in the system just as a greenhouse provides stability.

[Solly]

Does anyone think that Kerry Emanuel and Judith Curry each have an obligation to issue a report in Nature and/or Science on the 2006 hurricane season? Corporations can’t just issue financial statements when they have good years; they have to issue reports in bad years. And let there be no doubt - 2006 was a “bad” year for hurricane alarmists. I’ve collated all the storm track data to date. Storm and hurricane days are each off 30%; cat 3+ days by 50% and cat 4+ days by 54%. Hurricane days were at their lowest levels since 1989 and storm days at their lowest levels since Dvorak measurements were introduced in the Pacific in 1987. To my knowledge, this is the first quantitative report of these 2006 hurricane results. Emanuel had something in print using 2005 hurricane data in December 2005 (Reply to Landsea). What’s the over/under on when Emanuel and/or Webster/Curry will report on 2006 results in peer reviewed literature?

- Steve McIntyre

http://www.climateaudit.org/?p=919

[Odin]

Mr. McIntyre apparently forgot that El Ninos supress Atlantic hurricane activity and there is an El Nino right now...

[Barnabas]

There is an el niño? I dont see floodings in south america, it just started?

[Drake Tungsten]

Mr. McIntyre apparently forgot that El Ninos supress Atlantic hurricane activity and there is an El Nino right now...

Apparently you didn't read that the figure is a total of all storms in the five major hurricane basins worldwide (Atlantic, East Pacific, West Pacific, North Indian and South Indian/South Pacific). And given that El Nino increases Pacific storm activity at the same time it inhibits Atlantic storm activity...

[Berzerker]

but why does an El Nino suppress hurricane activity?