Tuesday, September 04, 2007

A farewell gift

Ethon brings word from Boulder that Roger P Sr. is retired from blogging. Climate Science is no more, although, had Eli to bet we might see RPSr. occasionally rise on Prometheus or elsewhere. Still Eth and Eli were sitting about the table wondering what gift we could send for the good times memories, when we remembered that Roger really, really wanted a measure of ocean heat content. Well, as the saying goes, what does not exist, sometimes has a proxy, and (we await correction from those who know better, such as llewelly) it may be that the hurricane track records found at Unisys might be such a proxy.

The strengthening of the storms should be related to the ocean heat content. A poor resolution perhaps, but averaged over some period of time, perhaps useful. Just an idle thought. Go gently sweet Climate Science.


llewelly said...

There's a Mann and Emanuel paper that shows Atlantic SSTs are predictor of seasonal TC counts (and also that global average anomalies are a predictor of Atlantic TC counts). I'm too tired to look it up right now, however.

There are some serious problems with using the hurricane record as a proxy for ocean heat content. First, observational methods and instrument characteristics have changed much more for hurricanes than they have for other potential proxies such as the historical record of SSTs. There are hurricanes like Dog and Easy where essentially all the windspeed estimates are from observers flying just under the cloud deck in the hurricane, and making a visual estimation of the wind speed based on the appearance of the violent ocean below. These are mixed in with numbers from various kinds of aneometers, including the infamous cup aneometers, estimates from observed damage (sometimes with photos, sometimes without, sometimes with all sorts of measurements of missile dimensions, other times not), estimates from various kinds of satellite imagery, from dropsondes, SFMR, and lots more. Second, moisture, dust, shear, and other factors also play strong roles in TC development. The result is that the statistics are noisy. And that's only the Atlantic.

Marion Delgado said...

hey llewelly:

Exactly as I predicted:

replicant said...
1933 according to this site: http://www.noaanews.noaa.gov/stories2005/s2518.htm
And 1887 before that. So we're hardly seeing anything different, except our ability to analyze and classify.

3:51 PM

anonymous said...
Yeah, I see that, except they weren't back-to-back Cat 5s.


4:08 PM

replicant said...
Since the categorization didn't exist then, you can't really say that. And chances are some hurricanes came and went without detection, or without continuous monitoring to know how intense they were at any given moment.

Of course, that list was too early to be useful. Later in the year you find:


Records this [2005] season include the totals for:

   • Named storms: 28; previous record: 21 in 1933

   • Hurricanes: 15; previous record: 12 in 1969

   • Major hurricanes hitting the U.S.: Four (Dennis, Katrina, Rita and Wilma); previous record: Three, most recently in 2004

   • Hurricanes of Category 5 intensity (greater than 155 mph): Four (Emily, Katrina, Rita and Wilma); previous record: Two in 1960 and 1961

Anonymous said...

Funny guy, Eli.

After clicking on that URL, I'm saying to myself, "That's odd why would they take down the entire site", like it was the Big Top Tent for some circus that came to town and then left.

But the real URL is www.clinatesci.colorad.edu, of course.

Then again...

Anonymous said...

Sorry, that was not intentional (really).

The real URL is http://climatesci.colorado.edu

BTW, my condolences to Steve Bloom, who must be heartbroken.


EliRabett said...

Obviously the tracks are noisy, but noisy averages out, and the tracks, where we have them are proxies. This is more in the tradition of something is better than nothing.

Hank Roberts said...

The perfect gift:

EliRabett said...

Hank, you are very evil. . .

Hank Roberts said...

Not yet. But I'm working on it.

This could become the agreed seekrit signaling device --- semaphore! -- for the climate quick response cabal.

llewelly said...

Prior to about 1950, only landfall damage could distinguish a category 5 from a 4. The 1928 'Okeechobee', 1932 'Bahamas' , 1935 'Labor Day', and 1947 'Fort Lauderdale' are agreed to be category 5s primarily due to extreme landfall damage. So 'replicants' complaint that the category had not been established is not the reason there are no back-to-back cat5s in 1933. Most category 5s do not make landfall at that strength - but a 1933 ship is not likely to survive and record category 5 winds. The problem was not the non-existence of the Saffir -Simpson scale, but the inability to record them at sea. Also - we know from seasons like 1999 that it is possible for the Atlantic to be extremely active, have many major hurricanes (like 1933), and yet have no category 5s.

Beyond that, past seasons are reanalyzed as much as resources allow (but arguably not enough) and I'm sure 1933 has gotten plenty of attention.

EliRabett said...

Thank you llewelly. I think thank you Hank.

Marion Delgado said...

by the way, "replicant" went for an early in the year page. I think that's a non-negligible point. Clearly one should wait till after the season is over before judging it.

it strikes me that the people touting 1934 as really the hottest year (in the contiguous lower 48 - in NOAA's list it's #3 and 1933 is #21) and 1933 as really just as bad as 2005 - which I don't buy - are at least implicitly indicating some sort of connection - more warming leading to a worse season. So here, the denialists are shooting themselves in the foot.

Anonymous said...

"So here, the denialists are shooting themselves in the foot."

Do they have any feet left?

Anonymous said...

Perhps some people like a few more details rather than "possibilities". To each their own.

Anonymous said...

As a send-off gift to RP Sr, I vote that we all chip in and buy him an "urban heat island -- perhaps in the arctic ocean off the coast of northern Siberia.

If one does not yet exist, we can create it -- complete with tennis court, barbecue grills and AC's in every window.

Then he can invite Anthony Watts over for cookouts on the weekends (and to continue his amateur photography hobby, of course)

Hank Roberts said...

Okay, I admit it, I'm evil.