Statistical analysis that warmer oceans caused the crazy hurricains last year

[ComputerGeek]

http://sciam.com/article.cfm?chanID=sa003&articleID=000051A6-DE14-1419-9E1483414B7F0000

Well, what do you all think?

 

[Astronuc]

Well, it is pretty hard to say with certainty that one event was 'caused' by a specific factor. The Atlantic Ocean, Caribbean Sea and Gulf of Mexico were apparently slightly warmer than in the past, and we did have two powerful hurricanes. While there appears to be a correlation, it doesn't necessarily indicate a cause and effect relationship, but that could very well be the case.

The big question is then - is this an anomaly, or is this a trend? If it is a trend, then we should expect more such devastating events in the near term.

Certainly the insurance industry is concerned.

 

[smurfslappa]

Skeptics called other factors into account, such as natural variability, but a new statistical analysis shows that only this sea surface temperature increase explains this trend.

Boo this article!

Here's a little question somebody had about the strange glow they saw in the eye of a hurricane:
http://www.usatoday.com/weather/resources/askjack/wahlight.htm

Is warm water the only contributing factor? No, but it helps.

 

[Bystander]

"The link between rising ocean temperatures and overall climate change remains murky because of the overlap between natural cycles and any global warming. "But if you buy the argument that global warming is causing the increase in sea surface temperatures--and everybody seems to be buying this--then it's a pretty small leap to say global warming is causing this increase [in hurricane frequency]," Curry says."

Says it all --- "But, Mom, everybody else is doing it."

 

[Mk]

http://sciam.com/article.cfm?chanID=sa003&articleID=000051A6-DE14-1419-9E1483414B7F0000

Well, what do you all think?

It was caused by variations in the Atlantic multidecadal oscillation. There was also wind shear, and warmer winds coming from Africa that were more favorable for cyclone formation in the Atlantic.

http://en.wikipedia.org/wiki/Atlantic_Multidecadal_Oscillation#Relation to Atlantic hurricanes

http://www.ncdc.noaa.gov/img/climate/research/2005/katrina/atl-multidecadal-signal.gif
http://www.ncdc.noaa.gov/img/climate/research/2005/ann/namedstorms-majorhurr.gif

 

[smurfslappa]

This article makes for some good reading.

http://pesn.com/2005/10/21/9600193_Wilma_Energy_from_the_Vacuum/

 

[Mk]

This article makes for some good reading.

http://pesn.com/2005/10/21/9600193_Wilma_Energy_from_the_Vacuum/

No it doesn't, its a crack site.

The electromagnetic freeze "ray" is beaming the energy away fast. The amount here is equal the detonation of a 20 megaton Hydrogen bomb every few minutes. To strip the planet of this much heat this fast requires an ionic short circuit into deep space.

If this hasn't confused you, then you are well on your way to understanding hurricanes and similar storms. It also removes any doubt that there is plenty of energy around to be used. This is the fast trip into the wild and wooly side of physics that is not popular with the tired old heads that dominate the field. (Don't bother those guys! They are mean and they don't take evidence well.

 

[loseyourname]

This article didn't link rising temperatures to the hurricanes last year. In fact, it said that locally and within single season, plenty of other variables play just as significant a role. It's only globally and over the last 35 years that they've been able to isolate rising surface temperatures as the only trend. Wind shear, wind variation, and specific humidity haven't been trending upward over 35 years (I'm not even sure they could), but they certainly could have contributed to last year's abnormal season.

All in all, the title of this thread is a little misleading, since the article doesn't actually make that claim.

 

[dand5]

It was caused by variations in the Atlantic multidecadal oscillation. There was also wind shear, and warmer winds coming from Africa that were more favorable for cyclone formation in the Atlantic.

I think the number of cyclones ejecting from the "african train" was about average and that combined with little pacific tampering (no El Nino) allowed most of them to develop into storms. But it should be noted that what was particularly astounding about last hurricane season was the number of storms that became strong enough to be named and that is directly related to warm water temperatures.

Also, I would be careful about saying that it was caused by AMO because these "oscillations" are really only visible with Fourier decompositions on SST data that is relatively small in size (150 years I think). And the fact that there is a dominant frequency in a small finite data set does not imply that the population from which the data set belongs actually has any periodicity to it at all. Though, I agree that warm water does allow storms to strengthen more.

 

[Mk]

I think the number of cyclones ejecting from the "african train" was about average and that combined with little pacific tampering (no El Nino) allowed most of them to develop into storms. But it should be noted that what was particularly astounding about last hurricane season was the number of storms that became strong enough to be named and that is directly related to warm water temperatures.

Hey dand, welcome to Physicsforums!

I don't see how El Niño "allowed most of them to develop into storms."

 

[dand5]

Hi Mk, thanks for the welcome.

But I don't think I said that El Nino allowed them to develop into storms, what I said was that the absence of an "El Nino"/other pacific signals did not prevent them from developing into significant storms.

 

[Mk]

So what affect does Pacific El Niño have on Atlantic cyclone formation?

 

[dand5]

Statistically fewer atlantic cyclones mature into tropical storms during pacific El Ninos.

http://www.aoml.noaa.gov/hrd/Landsea/elnino/

Theoretically, El Nino episodes increase vertical wind shear and hence turbulence which distort and mix out the latent heat release from developing cyclones over a larger distorted area thereby weakening the storms. I have heard people refer to this as "tearing or shearing apart the storms."

 

[reasonmclucus]

I think the number of cyclones ejecting from the "african train" was about average and that combined with little pacific tampering (no El Nino) allowed most of them to develop into storms. But it should be noted that what was particularly astounding about last hurricane season was the number of storms that became strong enough to be named and that is directly related to warm water temperatures.

Then how do you explain Hurricane Vince which developed into a hurricane over water that was under 80 F or 26 C?

 

[reasonmclucus]

No it doesn't, its a crack site.

The discussion on the site is questionable, but the basic concept of the "dry tongue" or cold arctic air makes sense. The term "dry tongue" is used on some noaa pages, but doesn't seem to be the preferred term. Cold air aloft, which will be dry because it cannot hold much water, does play a role in storms. One of our worst years for tornadoes and large hail in Kansas occurred when we had a large area of unusually cold air from Siberia over the state.

Storms occur not because of a "short circuit" but because the basic mixing of warm moist air and cold dry air creates an explosive situation.

 

[Mk]

Then how do you explain Hurricane Vince which developed into a hurricane over water that was under 80 F or 26 C?

Presuming that the "African train" are easterlies coming from North Africa, they are not the main cause, but create more favorable conditions for cyclone development.
http://www.mwnx.net/users/mac/atl-multidecadal-signal.gif

 

[I_AM]

I am new to the site, so I am a little late to the discussion, to my benifit

Judging by the lack of Hurricanes last season ( 2006) there is no direct connection to the A.G.W. debate.

From http://www.cnn.com/2006/WEATHER/11/30/hurricanes/index.html

2006 hurricane season bows out quietly
MIAMI, Florida (CNN) -- Defying predictions, the 2006 Atlantic hurricane season ended with a whimper rather than a bang on Thursday, without a single hurricane hitting U.S. shores.

The forecasters' crystal balls were made cloudy by the unexpected formation of the El Nino phenomenon in the Pacific Ocean in midsummer, weather experts said. Even the most sophisticated computer models couldn't see El Nino coming to dampen tropical activity in the Atlantic

"This year, our August forecast was the first August forecast ever to over-forecast the activity," Bell said. "So this is not a common thing."

This year was also unusual because no tropical systems formed at all in October. That is the first time that has happened since 1994, according to the hurricane center.

But despite this year's respite, forecasters are quick to point out that hurricane activity moves in cycles and the Atlantic basin remains in a very active area that could last another 20 years.

 

[Andre]

The current El Nino has been predicted by late Theodore Landscheidt in 2003:

PC/8 in 2007.2 has El Niño potential. As the date 2007.2 is closer to 2006/2007 than to 2007/2008 it is to be expected that El Niño will already emerge around July 2006 and last at least till May 2007 (Probability 80 %).

http://www.john-daly.com/theodor/new-enso.htm

This El Nino became apparent in Aug-Sept 2006, which should strenghten his ideas about the solar cycles and it's effect on climate.

It should be noted that there were also no hurricanes before El Nino.