Warming worsens hurricanes--more evidence

[Martin]

http://www.aip.org/pnu/2006/split/793-1.html

 

new study contributes evidence that global warming makes Atlantic hurricanes more deadly

 

anybody want to argue?

 

in related news, a crack opened in the artic ocean ice

http://www.esa.int/esaCP/SEM7ZF8LURE_index_0.html

(a cheerful Iceland blogger says this trend will make Chinese consumer goods cheaper in Europe because the container ships will go direct by polar route instead of the long way south around India and Africa, or thru Suez canal. great.)

 

===quote===

Mark Drinkwater of ESA’s Oceans/Ice Unit said: “This situation is unlike anything observed in previous record low ice seasons. It is highly imaginable that a ship could have passed from Spitzbergen or Northern Siberia through what is normally pack ice to reach the North Pole without difficulty.

 

"If this anomaly trend continues, the North-East Passage or ‘Northern Sea Route’ between Europe and Asia will be open over longer intervals of time, and it is conceivable we might see attempts at sailing around the world directly across the summer Arctic Ocean within the next 10-20 years."

===endquote===

[Martin]

===exerpt===

A new study of climate data suggests that global warming is causing the Atlantic Ocean to generate deadlier hurricanes. Hurricanes have become stronger in recent decades, in apparent correlation with the raise in atmospheric temperatures. Indeed James Elsner of Florida State University in Tallahassee reports in Geophysical Research Letters that there is in fact a clear cause-and-effect link.

 

...while the number of tropical cyclones had not increased between 1970 and 2004, their strength had surged: Category-4 or -5 hurricanes where more than 50 percent more frequent in the second half of that period than in the first...

 

...

Some climatologists believe that global (atmospheric) warming is causing the oceans' temperatures to rise, and that warmer sea surfaces can in turn add to a hurricane's strength. But others attributed nature's increased wrath to a long-term cyclic fluctuation in sea temperatures called the Atlantic Multidecadal Oscillation. Opinions also varied on whether a warmer atmosphere can significantly make the oceans warmer, ...

 

Elsner (jelsner@garnet.acns.fsu.edu) used an elaborate statistical method (first devised by economics Nobel Prize winner Clive Granger) ... His analysis showed that the spikes in atmospheric temperature mostly tended to come right before hurricane-season spikes in oceanic temperature, suggesting that the first were causing the second. Global warming could indeed be causing stronger hurricanes.

===endquote===

 

 

I wouldnt say it has been PROVEN. this is just a gradual build-up of evidence.

 

warmer air tends to cause warmer surface water temp

 

one still has to show that warmer surface water causes deadlier storms.

[silverslith]

I keep a close watch on hurricane activity and sea surface temperatures etc.

The SST's this year are frightening with up to 50% of the gulf of m over 30degc even this far into autumn- something that didn't happen at all even last year. The SST Anomaly data this year is showing some very troubling hot spots in the north atlantic where the warm saline gulf stream cools and decends as compared with normalised data.

The hurricanes this year have been largely suppressed in the caribean and gulf by sahara dust coming accross and capping their convection. Unlike last year the Atlantic has Cyclone sustaining SSTs, right across it at lattitudes up to 45degr nth, hence Gordon almost going from the bahamas to Ireland as a full hurricane. Ireland today, hurricane yesterday.

It is possible that a more energetic atmosphere will limit the frequency of hurricanes as this warming trend accelerates- They don't handle vertical wind shear at all well. However with most of the atlantic a spawning ground from now on, we are going to see alot anyway and very likely they will hammer places in europe and north America that have considered themselves immune from full hurricanes. The increased coriolis effect as you go further north means that intensity will be higher further north for a given SST. All thats needed for a fully fledged, h2o vapour fueled convection cyclone is relatively still air and SST over 25degrC.

[Martin]

I keep a close watch on hurricane activity and sea surface temperatures etc.

The SST's this year are frightening with up to 50% of the gulf of m over 30degc even this far into autumn- something that didn't happen at all even last year. The SST Anomaly data this year is showing some very troubling hot spots in the north atlantic where the warm saline gulf stream cools and decends as compared with normalised data.

The hurricanes this year have been largely suppressed in the caribean and gulf by sahara dust coming accross and capping their convection. Unlike last year the Atlantic has Cyclone sustaining SSTs, right across it at lattitudes up to 45degr nth, hence Gordon almost going from the bahamas to Ireland as a full hurricane. Ireland today, hurricane yesterday.

It is possible that a more energetic atmosphere will limit the frequency of hurricanes as this warming trend accelerates- They don't handle vertical wind shear at all well. However with most of the atlantic a spawning ground from now on, we are going to see alot anyway and very likely they will hammer places in europe and north America that have considered themselves immune from full hurricanes. The increased coriolis effect as you go further north means that intensity will be higher further north for a given SST. All thats needed for a fully fledged, h2o vapour fueled convection cyclone is relatively still air and SST over 25degrC.

 

thanks for the look in depth! you impress me as pretty darn savvy!

 

the article I saw had no special relevance to the near term AFAICS. it was more establishing a causal connection between two longterm things (which could be masked by shortterm fluctuation and special effects like those you mention)

 

I had heard that this year was predicted to be mild, but I had not heard it explained. Is the reason this Sahara dust "capping" effect you mentioned?

[silverslith]

thanks for the look in depth! you impress me as pretty darn savvy!

 

the article I saw had no special relevance to the near term AFAICS. it was more establishing a causal connection between two longterm things (which could be masked by shortterm fluctuation and special effects like those you mention)

 

I had heard that this year was predicted to be mild, but I had not heard it explained. Is the reason this Sahara dust "capping" effect you mentioned?

 

Definately an unusual belt of saharan dust so far this season. Its been restricting cyclones to mid atlantic and the pacific belt. Theres record SST's sustaining particularly in the GoM, possibly due to less cyclonic mixing than last year and if the upper level Saharan flow breaks then there is potential risk of a very large event yet this year.

[silverslith]

Actually this year was predicted by NOAA to be a major hurricane season.

The mid atlantic and pacific activity backs this.

Helene is now predicted to only lose hurricane strength a day before reaching Scotland.

 

The Atlantic SST loop:

http://www.ssd.noaa.gov/PS/TROP/DATA/RT/sst-atl-loop.html

 

Is showing that in the last few days the Gulf of Mexico had over 80% of its surface above 30degrC. Last year only a few small patches with less than 5% of the total area reached this.

[silverslith]

Correction. Helene has gone extratropical a day earlier than predictions, and will hit Ireland as the second serious cyclone remnant storm system in a week within 48 hrs.