Stronger SST-intense hurricane link?

By: Dr. Jeff Masters , 2:53 PM GMT on April 12, 2006

Share this Blog
0
+

A link between global warming and increased intense hurricane activity is a very hot topic in hurricane research right now, and many new papers on the subject will be published this year. The latest paper, published March 15 in the on-line version of Science, Science Express, finds stronger evidence that the increasing number of Category 4 and 5 hurricanes globally since 1970 is directly linked to increases in Sea Surface Temperature (SST). The paper by Hoyos et al. was called, "Deconvolution of the Factors Contributing to the Increase in Global Hurricane Intensity". Two of the co-authors--Peter Webster and Judith Curry of Georgia Tech--were also authors of a paper published in Science magazine in 2005 that reported a worldwide increase in the number of Category 4 and 5 hurricanes of 80% in the past 30 years. The paper, (Webster et al., 2005), titled "Changes in Tropical Cyclone Number, Duration, and Intensity in a Warming Environment", linked the rise in storms to increasing sea surface temperatures and concluded that "global data indicate a 30-year trend toward more frequent and intense hurricanes." As I reported in my blog on the subject, their findings should be considered as preliminary evidence that the global incidence of Category 4 and 5 hurricanes may be increasing. There are some severe problems with the quality of the data set used to, and there are good reasons to believe that the actual increase in Category 4 and 5 hurricanes is far lower than the 80% increase found by Webster et al.

The new paper by Hoyos et al. uses a mathematical technique called information theory to study the relative effects of SST, wind shear, humidity, and wind patterns on global incidence of Category 4 and 5 hurricanes. The study found that only SST can explain the observed increase in these storms. One thing I like about the new study is that it directly addesses the issue of data quality in the record of Category 4 and 5 hurricanes, something the authors neglected to do in their previous paper. The authors write, "Recently, the quality of the hurricane data has been questioned and even a reanalysis of the tropical cyclone databses has been suggested in order to ratify that the results of recent studies are not due to problems in the data." The authors go on to say that they performed their analysis without using suspect data from the North Indian Ocean, and found no difference in their results. Well, that's not too surprising, since the number of Category 4 and 5 hurricanes in that ocean basin represents only about 2% of the global total. What I would have liked to have seen was the analysis re-done using the latest reanalyzed results for typhoons from the Western Pacific, which accounts for 48% of global Category 4 and 5 hurricanes. In a paper accepted for publication but not yet finalized, Knaff and Zehr (2006) make convincing arguments that typhoon intensities during the 1973-1986 period were too low due to measurement error, and the number of Category 4 and 5 storms in the region have been roughly constant for the past 50 years. Dr. Knaff and Charles Sampson have performed a preliminary re-analysis of maximum typhoon intensities for the period 1966-1987 based on the Knaff and Zehr (2006) results. In a paper to be presented at the upcoming 27th Conference on Hurricanes and Tropical Meteorology (April 24-28, 2006), they show that after correcting for the measurement errors, the number of Category 4 and 5 typhoons during the 1966-1987 period increased by 1.5 per year, leaving only a slight upward trend in Category 4 and 5 typhoons during the period 1970 - 2004. The 16% increase in Category 4 and 5 typhoons found by Webster et al. during the past 15-year period is reduced to just 3%. I suspect that if the information theory techniques of Hoyos et al. were applied to this modified data set, the connection between SST and an increase in global Category 4 and 5 hurricanes would be much weaker.

The realclimate.org blog has more information on the paper, along with links to quotes in the media from many of the scientists involved in the hurricanes/global warming debate.

My next blog will be on Friday. Apparently, NHC has "found" a new Atlantic subtropical storm that formed in 2005, bringing the total for the season to 28 named storms. If the final report on this new storm has been issued, I'll discuss that.

Jeff Masters

references
Hoyos, C.D., P.A. Agudelo, P.J. Webster, and J.A. Curry, "Deconvolution of the Factors Contributing to the Increase in Global Hurricane Intensity", www.scienceexpress.org, 16 March 2006, 10.1126/science.1123560.

Knaff, J.A., and R.M. Zehr, "Reexamination of Tropical Cyclone Wind-Pressure Relationships", accepted to Weather and Forecasting, 2006.

Webster, P.J., G.J. Holland, J.A. Curry, and H.-R. Chang, "Changes in Tropical Cyclone Number, Duration, and Intensity in a Warming Environment", Science, 309, 1844,1846, 16 September 2005.

Alpha Chi Omega missing a wall (Arian)
The twister tore a whole wall from the sorority house and detroyed everything around it.
Alpha Chi Omega missing a wall

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 56 - 6

Page: 1 | 2 | 3 | 4 | 5 | 6Blog Index

56. rwdobson
7:15 PM GMT on April 12, 2006
"rwdobson, one small mistake--greenhouse forcing is as yet still just over 2 watts/meter2. However, that number will increase as CO2 concentrations rise."

actually, that's a pretty big difference...but since the GHG forcing is constant, while the solar forcing seems to oscillate, I still think GHG would be more significant.

did we really not start measuring solar rad until 1979?
Member Since: June 12, 2002 Posts: 0 Comments: 1574
55. caneman
7:14 PM GMT on April 12, 2006
Well I don't know much about all this global warming razzmatazz or globization or global whatever.

But one thing I doknow is this........weather will happen tomorrow. The CSE says it, therefore it must be so.
Member Since: Posts: Comments:
53. ForecasterColby
6:36 PM GMT on April 12, 2006
Looking at the sat archives, it's easy to miss. The storm very much blends into the banding of the colossal extratropical storm to its west.

And not to burst anyone's "it's the off season nothing will develop" bubble, shear is only 20kt off Florida.

Global warming people - stop with the personal attacks.

*slides in with plug for his site

There's a pretty interesting area at the tail end of that front, it looks to be developing a low and, though shear is almost 100kt now, it'll be dropping quickly in the next couple days.
52. rwdobson
5:55 PM GMT on April 12, 2006
interesting, it had tropical characteristics for all of 18 hrs...I guess we can forgive the NHC for missing it.
Member Since: June 12, 2002 Posts: 0 Comments: 1574
51. DaAntiCyclone
12:48 PM EST on April 12, 2006
Final storm report of the 2005 hurricane season has been posted.

Subtropical Storm #19
Member Since: Posts: Comments:
50. rwdobson
5:40 PM GMT on April 12, 2006
whatever, wannabe.
Member Since: June 12, 2002 Posts: 0 Comments: 1574
49. weatherwannabe
5:34 PM GMT on April 12, 2006
Not "sides" in the sense that you are using the term. Youa re using "sides" in relation to some extra-scientific motive. For example, there is a intelligent design side, so there4 has to be an anti-ID side even though most scientisits are reluctant to be forced into that role. But their motive is not to be anti ID, it is to be pro science. Do you understand the difference, Dobson?
Member Since: Posts: Comments:
48. rwdobson
5:33 PM GMT on April 12, 2006
you weren't talking about 'sides'? then why did you say this: "You mean the side that is interested in truth through scientific research versus the side that is funded by energy companies and corpratist PACs and think tanks."
Member Since: June 12, 2002 Posts: 0 Comments: 1574
47. weatherwannabe
5:30 PM GMT on April 12, 2006
The false dichotomy was the assumption that one side is motivated by pure science, and nothing else, and that the other side is motivated by greed, and nothing else.

I wasn't talking about "sides", dobson. I was talking about real science versus phony pseudo science. The kind that at first tried to claim that there was no global warming, but when the evidence became overwhleming switched to "it's not human induced".
Member Since: Posts: Comments:
46. rwdobson
5:28 PM GMT on April 12, 2006
Back to science again...the solar variation theory. According to the graph posted by St Simons, the variation in solar irradiation is only about 2 watts/m2 from the high point of the cycle to the low point.

from what i recall, the forcing caused by greenhouse gases is about 5 watts/m2. therefore, i would expect the GHG effect to be much larger than the solar effect.
Member Since: June 12, 2002 Posts: 0 Comments: 1574
45. weatherwannabe
5:28 PM GMT on April 12, 2006
rwdobson, you follow your own advice and we'll be just fine.
Member Since: Posts: Comments:
44. rwdobson
5:27 PM GMT on April 12, 2006
The false dichotomy was the assumption that one side is motivated by pure science, and nothing else, and that the other side is motivated by greed, and nothing else.

Member Since: June 12, 2002 Posts: 0 Comments: 1574
43. louastu
1:26 PM EDT on April 12, 2006
Take it somewhere else please. You both have the capability of creating your own blogs, and by taking your attacks on one another elsewhere, you will save us all the grief brought on by your childish comments.
42. rwdobson
5:25 PM GMT on April 12, 2006
Wannabe, if you wish to discuss science, please do so and I will respond. I will ignore future personal attacks.

ps I only have an MS, not a PhD, so don't call me doctor.
Member Since: June 12, 2002 Posts: 0 Comments: 1574
41. weatherwannabe
5:25 PM GMT on April 12, 2006
Levi32, dobson can take it if he can dish it out.
Member Since: Posts: Comments:
40. weatherwannabe
5:22 PM GMT on April 12, 2006
perhaps you should go and see if you can find a definition of "false dichotomy". Because what you have written is a classic example of one.

Wrong, again, Doctor. Science is objective and neutral by its very definition. We are comparing REAL science with phony psuedo science. Please keep up.
Member Since: Posts: Comments:
39. Levi32
9:22 AM AKDT on April 12, 2006
wannabe don't start anything.
Member Since: Posts: Comments:
38. oriondarkwood
5:12 PM GMT on April 12, 2006
You are all wrong global warming is caused by a combo of cow/sheep farts and the increased huff and puffing all us fat arsed people from trying to chase that girl next door that is jogging by us while carrying a steak (while are brains are fiquring out which meat to go after first).

And soon we enter a new ice age due to all that fat will tilt the earth and we will fall out of orbit..

And yes Aliens gave us the internet

(ROLFMAO)

Seriously the issue has been around long before most of us where born and will be around long after we are dead. Senseless attacks and name calling is really a waste of effort and blog space.
Member Since: Posts: Comments:
37. weatherwannabe
5:19 PM GMT on April 12, 2006
Professor rwdobson, is it? Should we call you Doctor?
Member Since: Posts: Comments:
36. lightning10
4:54 PM GMT on April 12, 2006
Wow this is my favorit post in a long time. The article was very informative. I understand that the article above is only a theory but it makes sence if you think about it.

I like how it brought up the point of how a lot of the hurricanes use esitmated data since a lot of them are not flown through.
Member Since: Posts: Comments:
35. louastu
1:12 PM EDT on April 12, 2006
I sense that this entire blog is about to be filled with personal attacks, which are completely childish, and uncalled for.

This site is very informative, interesting, and sometimes amusing. Please don't ruin it.
34. rwdobson
5:08 PM GMT on April 12, 2006
"rwdobson, please choose one:
a. global warming caused by human acitivity is a myth
b. global warming is caused by increased solar activity
c. scientists agreeing with 1 and 2 are being gagged by pinko liberal commie fear mongering greedy self interested Al Gore supporting scientists
d. 'meme' is not a word
e. Oil Companies have your best interest at heart
f. all of the above"

g. weatherwannabe does not understand science well enough to contribute to an informed debate
h. human activites have almost certainly affected the earth's climate
i. we do not know enough to accurately predict these changes or the long-term impacts of them
j. g., h., and i. are all true

i choose j.
Member Since: June 12, 2002 Posts: 0 Comments: 1574
33. rwdobson
4:57 PM GMT on April 12, 2006
"You mean the side that is interested in truth through scientific research versus the side that is funded by energy companies and corpratist PACs and think tanks"

perhaps you should go and see if you can find a definition of "false dichotomy". Because what you have written is a classic example of one.

so far, you have not presented one bit of science in any of your postings today. it has all been inflammatory rhetoric. so it appears to me that YOUR allegiances clearly lie with politics, and not science.
Member Since: June 12, 2002 Posts: 0 Comments: 1574
32. fredwx
11:49 AM EST on April 12, 2006
TO weatherwannabe
The truth is likely somewhere in the middle.

See my post "Global Warming - Man or Sun?"

Member Since: Posts: Comments:
31. Levi32
8:52 AM AKDT on April 12, 2006
Like I said, I would have put a "G" option and picked that.
Member Since: Posts: Comments:
30. louastu
12:41 PM EDT on April 12, 2006
Here is a link to Dictionary.com's definition of "meme".

While I agree that global warming is taking place, I don't believe that humans are the biggest reason for global warming.

I don't believe that the Bush administration is surpressing scientists from expressing views that are skeptical of global warming, as I really can't think of a reason why they would want to.

Oil Companies have your best interest at heart.

That is the joke of the century.
28. HurricaneMyles
4:44 PM GMT on April 12, 2006
Dude, please dont act like tne two sides of the argumnt dont do the same excact things. Each side is just trying to further there ideas so they can get more funds. Don't act like one side is all holy and has the best interets of the world at heart and the other side is corrupt, because it just inst like that.

There are serious, well-researched topics on both sides of the debate, and to go Ad Hominem and begin attacking the person rather then idea is wrong, no matter how corrupt you may feel one side is.
Member Since: January 12, 2006 Posts: 5 Comments: 827
26. weatherwannabe
4:38 PM GMT on April 12, 2006
Again, wannabe, you are not making a great case for your beliefs. The unfortunate truth is that there is a lot of non-science that is used by both sides to this argument...and that is sadly true for many arguments related to science.

You mean the side that is interested in truth through scientific research versus the side that is funded by energy companies and corpratist PACs and think tanks. Yes, evidence is used by sides. But for very different purposes and of differing quality. Please link to the nutty leftist equivalent of that WSJ editorial. Otherwise you are making a false equivalnet out of valid scientific research (i.e., Dr. Masters posts on the topic
) and propoganda. Which makes one question, where do your allegiances lie, rdobson, with science or with politics?
Member Since: Posts: Comments:
24. Levi32
8:37 AM AKDT on April 12, 2006
Wannabe, I choose F, but I think there should be a G:

Scientists are not using all the facts and data. That is not true science.
Member Since: Posts: Comments:
23. weatherwannabe
4:31 PM GMT on April 12, 2006
rwdobson, please choose one:
a. global warming caused by human acitivity is a myth
b. global warming is caused by increased solar activity
c. scientists agreeing with 1 and 2 are being gagged by pinko liberal commie fear mongering greedy self interested Al Gore supporting scientists
d. 'meme' is not a word
e. Oil Companies have your best interest at heart
f. all of the above
Member Since: Posts: Comments:
21. Levi32
8:17 AM AKDT on April 12, 2006
In my blog I explain that the favorable conditions are south of the tropical high, but the subtropical jet stream is pushing it south. The jet is causing all the shear and until it moves north, the ridge can't move north.
Member Since: Posts: Comments:
20. rwdobson
4:13 PM GMT on April 12, 2006
Thanks, Levi. I am feeling verbose this morning.

The official NHC forecast for the gulf says that there will be high pressure at the surface and the upper levels, leading to fair weather. The upper high is favorable for development, but a surface high is not.
Member Since: June 12, 2002 Posts: 0 Comments: 1574
19. Levi32
8:14 AM AKDT on April 12, 2006
The thing is, it is not getting warmer everywhere, it is getting a lot colder in other places.
Member Since: Posts: Comments:
18. globalize
4:10 PM GMT on April 12, 2006
If global warming is happening, and at the accelerating pace that appears, just about everyone will recognize it soon.
Member Since: Posts: Comments:
17. Levi32
8:12 AM AKDT on April 12, 2006
Rather, I agree with both of your comments. You are too fast lol.
Member Since: Posts: Comments:
16. DAVIDKRZW
4:11 PM GMT on April 12, 2006
oh dran it lol when will we see it
Member Since: Posts: Comments:
15. Levi32
8:11 AM AKDT on April 12, 2006
rwdobson I totally agree.
Member Since: Posts: Comments:
14. rwdobson
4:11 PM GMT on April 12, 2006
Low shear does not automatically lead to tropical development...which is good, or we'd have a heckuva lot more storms to deal with.
Member Since: June 12, 2002 Posts: 0 Comments: 1574
13. rwdobson
4:06 PM GMT on April 12, 2006
Again, wannabe, you are not making a great case for your beliefs. The unfortunate truth is that there is a lot of non-science that is used by both sides to this argument...and that is sadly true for many arguments related to science.
Member Since: June 12, 2002 Posts: 0 Comments: 1574
12. Levi32
8:07 AM AKDT on April 12, 2006
David, I no longer think that these disturbances will develop. There are just too many hostile factors.
Member Since: Posts: Comments:
11. DAVIDKRZW
4:04 PM GMT on April 12, 2006
Link


her is a update of the shear the red mean low shear and the bule mean high shaer

and look how low it is in the gulf!
Member Since: Posts: Comments:
10. weatherwannabe
3:50 PM GMT on April 12, 2006
It's obvious, the majority of scientist's sole objective is to increase funding through fear mongering and to engage in poilitcal activism. Afterall, the scientists funded through energy firm's grants are just trying to get the truth out. Not to mention all those great scientific government jobs where you can work for politically appointed flunkies with falsified resumes.
Member Since: Posts: Comments:
8. rwdobson
3:42 PM GMT on April 12, 2006
Umm, to me this editorial seems relatively reasonable. Especially this part: "There are many reasons to begin a methodical transition to power sources that pollute less, beginning with the fact oil, coal and natural gas eventually will run out, and it would be irrational to switch to even dirtier fuels, such as wood. But the hysteria surrounding the anti-global-warming movement ill serves that cause."

Wannabe, when you immediately dismiss something as the "new meme [sic] of the coprotist neocon", while admitting that you don't know about the science, you don't help your side win any arguments.
Member Since: June 12, 2002 Posts: 0 Comments: 1574
7. rwdobson
3:38 PM GMT on April 12, 2006
Yes, it's clear that Dr Masters has been intimidated...that's why we've only seen 2 detailed blogs on the subject! And Dr Gray has clearly been silenced as well.

Member Since: June 12, 2002 Posts: 0 Comments: 1574
6. weatherwannabe
3:37 PM GMT on April 12, 2006
And here is another editorial making a similar claim that it is not human activity that is causing global warming, but just a solar cycle. This "solar cycle" is apprartnyly the new meme of the corportist neocon. I wonder if it has any real scientific credibility or has it jsut replaced their old meme of "what global warming".
Member Since: Posts: Comments:

Viewing: 56 - 6

Page: 1 | 2 | 3 | 4 | 5 | 6Blog Index

Top of Page

About JeffMasters

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.