Science > Physics > Rising ocean temperatures boost hurricanes, says study
| Topic: |
Science > Physics |
| User: |
"Sam Wormley" |
| Date: |
30 Jan 2008 09:32:28 PM |
| Object: |
Rising ocean temperatures boost hurricanes, says study |
Rising ocean temperatures boost hurricanes, says study
http://physicsworld.com/cws/article/news/32646
Researchers in the UK claim to have the first firm evidence that
rising sea-surface temperatures have boosted the intensity and
incidence of hurricanes that form in the tropical North Atlantic,
Caribbean and Gulf of Mexico. Mark Saunders and Adam Lea of
University College London (UCL) say that a 0.5-degree increase in the
temperature of the ocean surface results in a 40% increase in
hurricane activity.
Climate scientists have long suspected that warmer oceans mean more
hurricanes. In the 1950s and 1960s, the sea-surface temperature (SST)
in the tropical North Atlantic was relatively high and hurricanes
were relatively common, while in the 1970s and 1980s, the temperature
dipped by nearly one degree Celsius and the intensity and incidence
of storms also dropped. Then in the 1990s, the temperature began to
increase along with hurricane activity.
Notoriously complex
However, the Earth's climate is a notoriously complex system and
researchers have struggled to establish a direct relationship between
SST and hurricanes. An important complicating factor is that changing
wind patterns over the Atlantic play an important role in hurricane
formation \u2013 and it had been tricky to determine the relative
impact of wind and temperature.
Saunders and Lea have now got around this problem by doing a careful
statistical analysis of storm, SST and wind data stretching back to
1965 (Nature 451 557). First, they showed that about 75-80% of the
variation in hurricane activity was a direct result of changes in the
SST and wind patterns. Then, they assumed that the temperature and
wind patterns had independent effects on hurricane intensity and used
an analysis technique called multiple linear regression to remove the
influence of wind.
Accumulated cyclone energy
The researchers described the hurricane frequency and intensity in
terms of the accumulated cyclone energy (ACE) index for the North
Atlantic, which measures the total energy dissipated by hurricanes.
ACE is considered the most meaningful measure of hurricane activity
because it combines intensity and duration of all tropical storms in
a given season.
They found that a 0.5 degree Celsius increase in SST boosted the ACE
by about 40%. Furthermore, they say that much of the recent increase
in the ACE since 1996 can be attributed to a rise in the SST.
While Saunders and Lea were able to link SST to hurricane activity,
their work says nothing about why the SST has increased over the past
40 years. According to Saunders, this could be down to global warming
or it could be part of the cyclical variation of SST called the
Atlantic multidecadal oscillation, which seems to occur with a period
of about 60-80 years.
Improved climate models
However, Saunders told physicsworld.com that the result should help
those developing models that try to predict the outcomes of climate
change, because in order to be correct, these models should reproduce
the observed connection between increasing SST and hurricane
activity.
According to Stefan Rahmstorf, a physicist at the Institute for
Climate Impact Research at Potsdam University in Germany, this latest
work backs up previous studies that suggest that the connection
between SST and ACE is very strong indeed. "What is remarkable
in this study (and similar previous studies) is how strong the effect
of a very modest warming of half a degree is", Rahmstorf told
physicsworld.com "It makes you wonder what kind of hurricane
activity you'd get after three degrees warming."
Saunders, however, is more cautious about predicting what would
happen if the SST rose by such an amount. It is possible, for
example, that the SST is currently at a critical value for hurricane
formation and small deviations cause large changes in hurricane
activity. This might not be the case if climate change caused the SST
to rise by several degrees.
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| User: "Benj" |
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| Title: Re: Rising ocean temperatures boost hurricanes, says study |
31 Jan 2008 12:46:30 AM |
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On Jan 30, 10:32 pm, Sam Wormley <sworml...@mchsi.com> wrote:
Rising ocean temperatures boost hurricanes, says study
http://physicsworld.com/cws/article/news/32646
Researchers in the UK claim to have the first firm evidence that
rising sea-surface temperatures have boosted the intensity and
incidence of hurricanes that form in the tropical North Atlantic,
Caribbean and Gulf of Mexico. Mark Saunders and Adam Lea of
University College London (UCL) say that a 0.5-degree increase in the
temperature of the ocean surface results in a 40% increase in
hurricane activity.
Notoriously complex
However, the Earth's climate is a notoriously complex system and
researchers have struggled to establish a direct relationship between
SST and hurricanes.
Gosh the first evidence of SST to hurricane activity. Of course no
firm evidence before never stopped all those with an AGW agenda from
stating this connection as Fact. And even worse they had no problems
with bald-faced lies about how "Greenhouse gases" in general and CO2
in particular are supposed to be the cause of climate change. Note
that missing from this study is the fact that CO2 levels are a direct
function of SST. Get that? A change in SST CAUSES a change in CO2
levels. It is NOT as Algore and Co. keep bleating that increases in
CO2 levels cause a rise in SST. With luck maybe a hurricane will blow
all these propagandists away.
Left unsaid is the fact that it just might be wise to start looking
for REAL causes of the "notoriously complex" climate change before
some real trouble sets in, instead of spending tons of money on some
worthless political agenda designed to enrich a few. What? They think
that they don't live on the same planet we do?
.
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