Read the study. Then your "understanding" will change.

Don't comment on studies you haven't read -- then you won't get
embarassed in public saying stupid things.

Scott wrote:
Bill Habr wrote:
"Scott" wrote in message
...

Bill Habr wrote:

"Lloyd Parker" wrote in message
...


The article covers time since 1970. Believe it or not, the world was

rather


good at record-keeping back then.



Why didn't they look at before 1970?

Say go back to 1950 or 1960?

Oh wait, that would show a dip in activity from 1970 to 1995 and

wouldn't

show the dramatic increase but would show a fluctuation from high to low

and

back to high.

Or maybe they couldn't find satellite data from back in the 1950s.


Scott



So are you saying that presence of satellite data would show less activity?

If not you are making my point stronger.

I'm not sure what you mean.

It was my understanding that the study used satellite
data. How many weather satellites were flying the 1950s?

Scott

I double checked, the word satellite does not appear in the document.
I see no reason to leave out prior data. You could make a case that
storms might not be detected before satellites, but I think the issue
would be huricane hunter aircraft which I believe began in the 50's.

Huh? A dip from 1970 to 1955? Sorry, not what the study found. The number
of storms stayed fairly constant, but the percentage of major storms went up.

Try reading the article.

You are the one not reading the article! The study did not address the
issue of storms before 1970. If it had it would have found that the
storms of the 50s nearly numbered the present ones and the graph would
not have looked like an uptrend! Bill is entirely correct!

"Scott" wrote in message
...
Bill Habr wrote:
"Scott" wrote in message
...

Bill Habr wrote:

"Lloyd Parker" wrote in message
...


The article covers time since 1970. Believe it or not, the world was

rather


good at record-keeping back then.



Why didn't they look at before 1970?

Say go back to 1950 or 1960?

Oh wait, that would show a dip in activity from 1970 to 1995 and

wouldn't

show the dramatic increase but would show a fluctuation from high to
low

and

back to high.

Or maybe they couldn't find satellite data from back in the 1950s.


Scott



So are you saying that presence of satellite data would show less
activity?

If not you are making my point stronger.

I'm not sure what you mean.

It was my understanding that the study used satellite
data. How many weather satellites were flying the 1950s?

Scott

Question:

Leavingout all data from before 1970 enhances the study?


My point is that by using a period of time of below normal activity the
study skews.
Example:
Using the Accumulated Cyclone Energy Index, North Atlantic Hurricane
Activity.

1950 to 1971 inclusive (22 seasons)
Seasons with activty:
Above Normal 11

Normal 7

Below normal 4


1972 to 1994 inclusive (22 seasons)
Seasons with activty:
Above Normal 3

Normal 7

Below normal 12


1950 to 1994 inclusive (44 seasons)
Seasons with activty:
Above Normal 14

Normal 14

Below normal 16

In article . com,
says...

Scott wrote:


It was my understanding that the study used satellite
data. How many weather satellites were flying the 1950s?

Scott

I double checked, the word satellite does not appear in the document.
I see no reason to leave out prior data. You could make a case that
storms might not be detected before satellites, but I think the issue
would be huricane hunter aircraft which I believe began in the 50's.

You didn't read it carefully:

"Cyclone intensities around the world are estimated by pattern
recognition of satellite features based on the Dvorak scheme (25). The
exceptions are the North Atlantic, where there has been continuous
aircraft reconnaissance; the eastern North Pacific, which has occasional
aircraft reconnaissance; and the western North Pacific, which had
aircraft reconnaissance up to the mid-1980s. There have been substantial
changes in the manner in which the Dvorak technique has been applied
(26). These changes may lead to a trend toward more intense cyclones,
but in terms of central pressure (27) and not in terms of maximum winds
that are used here. Furthermore, the consistent trends in the North
Atlantic and eastern North Pacific, where the Dvorak scheme has been
calibrated against aircraft penetrations, give credence to the trends
noted here as being independent of the observational and analysis
techniques used. In addition, in the Southern Hemisphere and the North
Indian Ocean basins, where only satellite data have been used to
determine intensity throughout the data period, the same trends are
apparent as in the Northern Hemisphere regions."

Webster, P. J., G. J. Holland, J. A. Curry, and H.-R. Chang, 2005:
Changes in Tropical Cyclone Number, Duration, and Intensity in a Warming
Environment. Science, Vol 309, Issue 5742, 1844-1846 , 16 September
2005 [DOI: 10.1126/science.1116448]

Harold
--
Harold Brooks
hebrooks87 hotmail.com

On Tue, 20 Sep 2005 21:23:42 GMT, "Bill Habr"
wrote:

Question:

Leavingout all data from before 1970 enhances the study?

He didn't. He concentrated on global data from the 70s fwd because it
met the requirements. There's a myth around that he didn't look at
data before this, and focused incorrectly on the Atlantic basin.
Neither are true.

My point is that by using a period of time of below normal activity the
study skews.

Using bad data does the same thing. Emmanuel's primary contribution
to the process is the new perspective of total energy dissapation.
Studying temporal satellite data allowed him to do that.

Example:
Using the Accumulated Cyclone Energy Index, North Atlantic Hurricane
Activity.

1950 to 1971 inclusive (22 seasons)
Seasons with activty:
Above Normal 11

Normal 7

Below normal 4


1972 to 1994 inclusive (22 seasons)
Seasons with activty:
Above Normal 3

Normal 7

Below normal 12


1950 to 1994 inclusive (44 seasons)
Seasons with activty:
Above Normal 14

Normal 14

Below normal 16

Now you're the one making the error because you've focused on the
Atlantic Basin.

"The analysis by climatologist Kerry Emanuel of the Massachusetts
Institute of Technology shows for the first time that major storms
spinning in both the Atlantic and the Pacific since the 1970s have
increased in duration and intensity by about 50 percent."

http://www.livescience.com/forcesofn..._stronger.html

And the number of events world-wide has not changed from a range of
low 80s to about 90. So your objection that he chose a low to accent
the growth - is incorrect.

Altho your criticism doesn't reflect knowledge of Emmanuel's study, if
you read the article it's pretty clear that this is a new look in a
new way. And the right approach comes from the science - chew on it
for a while before any saying yea or nay to any conclusions or
connections.

Harold Brooks wrote:
In article . com,
says...

Scott wrote:


It was my understanding that the study used satellite
data. How many weather satellites were flying the 1950s?

Scott

I double checked, the word satellite does not appear in the document.
I see no reason to leave out prior data. You could make a case that
storms might not be detected before satellites, but I think the issue
would be huricane hunter aircraft which I believe began in the 50's.

You didn't read it carefully:

"Cyclone intensities around the world are estimated by pattern
recognition of satellite features based on the Dvorak scheme (25). The
exceptions are the North Atlantic, where there has been continuous
aircraft reconnaissance; the eastern North Pacific, which has occasional
aircraft reconnaissance; and the western North Pacific, which had
aircraft reconnaissance up to the mid-1980s. There have been substantial
changes in the manner in which the Dvorak technique has been applied
(26). These changes may lead to a trend toward more intense cyclones,
but in terms of central pressure (27) and not in terms of maximum winds
that are used here. Furthermore, the consistent trends in the North
Atlantic and eastern North Pacific, where the Dvorak scheme has been
calibrated against aircraft penetrations, give credence to the trends
noted here as being independent of the observational and analysis
techniques used. In addition, in the Southern Hemisphere and the North
Indian Ocean basins, where only satellite data have been used to
determine intensity throughout the data period, the same trends are
apparent as in the Northern Hemisphere regions."

Webster, P. J., G. J. Holland, J. A. Curry, and H.-R. Chang, 2005:
Changes in Tropical Cyclone Number, Duration, and Intensity in a Warming
Environment. Science, Vol 309, Issue 5742, 1844-1846 , 16 September
2005 [DOI: 10.1126/science.1116448]

Harold
--
Harold Brooks
hebrooks87 hotmail.com

H'mm, that doesn't appear in the article, perhaps the study itself, if
so please provide a link.

Bill Habr wrote:
"Lloyd Parker" wrote in message
...

The article covers time since 1970. Believe it or not, the world was

rather

good at record-keeping back then.



Why didn't they look at before 1970?

How many weather satellites were there before 1970 with global coverage?

Say go back to 1950 or 1960?

Not many satellites.

josh halpern

As long as they keep wiping out red states
I say,
"Bring 'em on!"



Roger Coppock wrote:

Please follow this URL to see the press release with a graph:
http://www.innovations-report.com/ht...ort-49334.html

Here's another reference (from National Geographic) that probably says
about the same thing:

". . .a new study in the journal Nature found that hurricanes and
typhoons have become stronger and longer-lasting over the past 30
years. These upswings correlate with a rise in sea surface
temperatures.

The duration and strength of hurricanes have increased by about 50
percent over the last three decades, according to study author Kerry
Emanuel, a professor of atmospheric science at the Massachusetts
Institute of Technology in Cambridge."

http://news.nationalgeographic.com/n...0804_hurricane...