We’ve known this for quite some time, but I wanted to offer my congratulations to Dr. Maue. I’m thankful that you are a WUWT contributor. – Anthony
AGU journal highlights — Aug. 18
The following highlights summarize research papers that have been recently published in Geophysical Research Letters (GRL), Journal of Geophysical Research-Earth Surface (JGR-F), Journal of Geophysical Research-Biogeosciences (JGR-G), and Journal of Geophysical Research-Oceans (JGR-C).
…
2. Global cyclone activity historically low
A new research study shows that overall global tropical cyclone activity has decreased to historically low levels during the past 5 years.
Maue analyzes global tropical cyclone data from 1970 through May 2011 to examine the considerable interannual variability of the accumulated cyclone energy (ACE) metric. Since 2006, global and Northern Hemisphere ACE have decreased significantly, reaching the lowest levels since the late 1970s. Also, during 2010-2011, the overall global frequency of tropical cyclones reached a historical low. The researcher demonstrates that much of the variability in tropical cyclone energy during the past 40 years is clearly associated with natural large-scale climate oscillations such as the El Niño-Southern Oscillation and the Pacific Decadal Oscillation.
Source:
Geophysical Research Letters, doi:10.1029/2011GL047711, 2011
http://dx.doi.org/10.1029/2011GL047711
Title: Recent historically low global tropical cyclone activity
Author: Ryan N. Maue: Center for Ocean and Atmosphere Studies, Department of Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, Florida, USA;
Major syntax failure from previous comment.
My apologies.
The total number of cyclones is not related to the global temperature, and, “historically”? If by that, you mean 1972 through 1910 (this year is far from over), that’s a bit short to qualify the period.
ClimateForAll says:
August 19, 2011 at 3:38 pm
It is crystal clear to me what he means.
======================================
good grief…….you didn’t understand a thing I posted
It has nothing to do with ACE…..I was only asking Ryan to clear up the word cyclone.
It can be confusing, in the Pacific a cyclone is a full blown hurricane.
In the Atlantic, it can just be a spinning squall line.
When you talk about numbers of cyclones or frequency of cyclones:
“Also, during 2010-2011, the overall global frequency of tropical cyclones reached a historical low”
It makes a big difference who you are talking to.
Are you talking about the frequency of full blown hurricanes, or the frequency of named squall lines.
The Australian BOM has statistics on cyclones from 1906 to 2007. Interesting that they “repaired” all their data in 2007.
I recall looking at the data some years ago to determine whether cyclones had increased over time in this region. I could see no evidence of this, in fact the opposite seemed to be the case.
It does not appear to be as easy to tell with the “repaired” data what the situation is although I am sure that an experienced meteorological statistician could do so:
http://www.bom.gov.au/cyclone/history/index.shtml#db
But we still have alarmists and politicians telling us that we are going to have more cyclones:
http://www.abc.net.au/news/2011-02-01/tc-yasi-caused-by-climate-change-greens/1925996
On what data do they base these statements? Because the BOM itself is completely vague on the issue in the paper they have helped the government to prepare Adapting to Climate Change in Australia (which also seems to change more than the weather):
http://www.climatechange.gov.au/government/adapt/adapting-to-climate-change-paper.aspx#note1-10
Even though they say “Human activities have already changed our climate” (I cannot find any real evidence that supports this claim) they ARE quite guarded about cyclones:
“We have limited information about how climate change will affect some extreme events such as cyclones and hail storms.”
Oh, if we could only look forward 20 years rather than backwards but then again some people have the knack of re-writing history to suit their argument.
I keep wondering if there is some ulterior motive for the NHC not updating this chart since 2005.
http://www.nhc.noaa.gov/climo/images/atlhist_hires.gif
Very good work Ryan! and nice you can be straight forward with the data, NO CAGW disclaimers or about the future missing heat to get published. Good solid science is all it takes to make a difference in the level of understanding of nature.
I would still like to know where/if I can find a data set for daily ACE values so i can plot them like I did with tornado production numbers.
http://research.aerology.com/lunar-declinational-affects-on-tornado-production/
Skeptic Tank,
Thanks for the interesting graphic. Here are some more from the same source:
http://www.nhc.noaa.gov/climo/images/hurr-uslandfalling-1950-2009.jpg
http://www.nhc.noaa.gov/climo/images/peakofseason.gif
http://www.nhc.noaa.gov/climo/images/cum-average_Atl_1966-2009.gif
Smokey,
Most of the info at the Tropical Cyclone Climatology page is fairly up to date (I assume). But the chart I mentioned is particularly relevant to this topic and conspicuous in its neglect. We’ve all known for the past few years that there has been a decrease in global tropical cyclone activity, including in the Atlantic. Why not update that chart for more than five years?
Skeptic Tank,
Good question. NOAA should also explain what the different colors represent.
“ryanm: the Earth has not warmed that much to see changes in global cyclone activity, yet. Maybe in 30 or 40 years in the future.”
And ever year the boundary moves 1 year further into the future. Disaster remains firmly pegged, maybe 30 or 40 years from whatever day it is now.
In point of fact, the end of the world is always 1 day ahead of the current day, and will remain firmly in that location until the end of the world.
Latitude says:
good grief…….you didn’t understand a thing I posted
It has nothing to do with ACE…..I was only asking Ryan to clear up the word cyclone.
It can be confusing, in the Pacific a cyclone is a full blown hurricane.
In the Atlantic, it can just be a spinning squall line.
=================================
A “cyclone” is any closed low circulation, or spinning atmospheric disturbance where air is moving toward low pressure in the center….so it is a very general term.
A “tropical cyclone” is any cyclone with tropical characteristics (i.e. a warm core system, air in the center is warmer then the surrounding)…across the globe.
It comes in many regional names:
Hurricane (Atlantic and East Pacific)
Typhoon (North Pacific)
Cyclone (Australia and Indian Ocean area)
What is probably confusing is sort of like the confusion of the term “Classical Music” which means generally any highly organized music that takes considerable skill to play and is composed on a score.
But “Classical” can also mean the more specific era of Classical music from about 1750 – 1830, but distinguished from the Baroque period and the Romantic period, etc.
So….all hurricanes, tropical storms, typhoons and the Aussie and Indian Ocean version “cyclones” are all the same beast: tropical cyclones.
But not all cyclones are tropical.
Mid-latititude lows, polar lows, tornadoes (technically) etc….are all cyclones, too.
Chris
Norfolk, VA, USA
“Bars depict number of named systems (open/yellow),
hurricanes (hatched/green), and category 3 or greater (solid/red), 1886-2004
Download hires image”
http://www.nhc.noaa.gov/climo/images/atlhist_hires.gif
According to the foot note of the graph.
[ryanm: Dave, my paper does not discuss AGW with respect to global hurricane activity……….
===============================================
lol, No, Ryan, it didn’t, but then, it didn’t have to. The message was loud and clear even without discussing the nonsense. I’ve cited your paper or web page probably over a hundred times in AGW discussions. Oddly, any discussion about hurricanes and cyclones in reference to AGW ceases after the citing. My many thanks.
King of Cool quotes:
August 19, 2011 at 5:24 pm
The Australian BOM
“We have limited information about how climate change will affect some extreme events such as cyclones and hail storms.”
———–
The story around how AGW will affect cyclone frequency is confused. Some modelling says it will go down. Some opinion is that the overall frequency will go down, but storms when they do occur will be more intense due to the way sea surface temperatures feed hurricanes.
There is an apparent contradiction with claims of more extreme weather events. Except “extreme weather events” is a very fuzzy term and there are many different kinds of extreme weather events.
Taking account of:
1. We can’t describe it properly with everyday language
2. We don’t know enough yet
3. We have trouble distinguishing the effect of multiple influences on climate, both short and long term
4. There is a lot of slipperiness around the term “cause”
I would advise against drawing dogmatic conclusions about Ryan’s research or any one else’s in this area.
Short answer the paper is not a disproof or proof of AGW.
So far, it seems that this hurricane season in the Atlantic has been relatively quiet – mostly tropical storms. Of course, there is September and October…
It is already a proven fact, not theory, that ACE correlates to Sunspot Activity.
Since cyclones are associated with high sea surface temperatures, could it be that the declining thermal energy in the upper ocean levels is corrolated with declining cyclone activity?
Anyway recall the resignation letter of Chris Landsea after some doubtful actions of Trenberth
http://www.climatechangefacts.info/ClimateChangeDocuments/LandseaResignationLetterFromIPCC.htm
“Shortly after Dr. Trenberth requested that I draft the Atlantic hurricane
section for the AR4’s Observations chapter, Dr. Trenberth participated in a
press conference organized by scientists at Harvard on the topic “Experts to
warn global warming likely to continue spurring more outbreaks of intense
hurricane activity” along with other media interviews on the topic. The
result of this media interaction was widespread coverage that directly
connected the very busy 2004 Atlantic hurricane season as being caused by
anthropogenic greenhouse gas warming occurring today. Listening to and
reading transcripts of this press conference and media interviews, it is
apparent that Dr. Trenberth was being accurately quoted and summarized in
such statements and was not being misrepresented in the media. These media
sessions have potential to result in a widespread perception that global
warming has made recent hurricane activity much more severe.
I found it a bit perplexing that the participants in the Harvard press
conference had come to the conclusion that global warming was impacting
hurricane activity today. To my knowledge, none of the participants in that
press conference had performed any research on hurricane variability, nor
were they reporting on any new work in the field. All previous and current
research in the area of hurricane variability has shown no reliable,
long-term trend up in the frequency or intensity of tropical cyclones,
either in the Atlantic or any other basin.”
savethesharks says:
August 19, 2011 at 8:08 pm
A “cyclone” is any closed low circulation, or spinning atmospheric disturbance where air is moving toward low pressure in the center….so it is a very general term.
A “tropical cyclone” is any cyclone with tropical characteristics (i.e. a warm core system, air in the center is warmer then the surrounding)…across the globe.
It comes in many regional names:
Hurricane (Atlantic and East Pacific)
Typhoon (North Pacific)
Cyclone (Australia and Indian Ocean area)
====================================================================
Chris, thanks….but you missed my point too
Let me try it again….
When you say “cyclone”, most people think “oh my God, we’re all going to die”, just like you used it (hurricane, typhoon, cyclone)
When in reality, “cyclone” is used to describe anything as small a non-event as a squall line with a spin……
With the NHC, NOAA, etc naming every non-event cloud with a spin…..and calling them cyclones
Ryan said:
“the overall global frequency of tropical cyclones”
“Global cyclone activity historically low”
Even with NHC, NOAA doing their best to name every tiny cloud, it’s still low……………….
Ryan,
Congratulations for you paper being on the spotlight. It speaks volumes about your work and dedication. Also, thank you for your contributions here on WUWT. Having lived all my life between 18 and 27 degrees N in “Hurricane Alley”, I’ve become very much a student of these storms and appreciate your posts.
I have two questions unrelated to your paper:
1) For many years I’ve been visiting the Experimental forecast Tropical Cyclone Genesis Potential Fields here: http://moe.met.fsu.edu/tcgengifs/
It is still marked as experimental. However, I’ve noticed that the TPC is now including cyclogenesis percentages on their web site as part of their forecast and the percentages they use closely match the spread of these models. Has the experimental status changed or did the TPC just decide to adopt these percentages regardless?
2) Are there any papers out there that cite any correlation between the start and severity of the Cape Verde season with monsoonal variations (onset and severity) in both the Indian subcontinent and Southeast Asia? I ask because during the last few years I’ve become casually aware that the onset of the Cape Verde Season seems to have a relationship to the amount of water vapor in the Indian Ocean, and specifically when a large amount of this water vapor is in continuous contact with the eastern coast of Tropical Africa. I use these water vapor images:
http://www.nrlmry.navy.mil/sat-bin/display10.cgi?SIZE=full&PHOT=yes&AREA=global/stitched&PROD=vapor&TYPE=ssmi&NAV=global&DISPLAY=Latest&ARCHIVE=Latest&CGI=global.cgi&CURRENT=20110820.0900.multisat.wv.stitched.Global.x.jpg&MOSAIC_SCALE=15
Through casual observation, it seems that when a large amount of water vapor from the Indian Ocean continually reaches Tropical Africa it causes the continuous “bloom” and “training” of thunderstorms that travel across the continent and come out on the Atlantic side with much greater potential for cyclogenesis. This water vapor conditions seem to be short lived, no more than a few weeks at most, and sometimes they’re on and off. I would love to read any paper available on the subject.
Thanks again for your participation here and congratulations!
Best,
J.
We’ll know this tempest
In the heart of Gaia ends.
Moody writes ‘Calm World.
================
Latitude says:
August 20, 2011 at 6:19 am
savethesharks says:
August 19, 2011 at 8:08 pm
A “cyclone” is any closed low circulation, or spinning atmospheric disturbance where air is moving toward low pressure in the center….so it is a very general term.
A “tropical cyclone” is any cyclone with tropical characteristics (i.e. a warm core system, air in the center is warmer then the surrounding)…across the globe.
It comes in many regional names:
Hurricane (Atlantic and East Pacific)
Typhoon (North Pacific)
Cyclone (Australia and Indian Ocean area)
====================================================================
Chris, thanks….but you missed my point too
Let me try it again….
When you say “cyclone”, most people think “oh my God, we’re all going to die”, just like you used it (hurricane, typhoon, cyclone)
When in reality, “cyclone” is used to describe anything as small a non-event as a squall line with a spin……
=================================
No. Actually I did not miss your point.
There is absolutely no reason to jump to those ridiculous conclusions.
You are conflating two different definitions of the word “cyclone.”
And…by the way…there is no such thing as a “squall line with a spin”.
No such thing whatsoever.
So….nothing to be concerned about at all….
Except about a tropical cyclone that might intensify to significant strengths and end the current quiet period.