One third of Arctic ice cap now missing; Midwestern floods; tropical update

By: Dr. Jeff Masters , 12:46 PM GMT on August 24, 2007

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Sea ice in the Arctic continues its record decline, thanks to unusually cloud-free conditions and above-average temperatures. For August 21, the National Snow and Ice Data Center estimated that fully one third of the Arctic ice cap was missing, compared to the average levels observed on that date from 1979-2000. Sea ice extent was 4.92 million square kilometers on August 21, and the 1979-2000 average for the date was about 7.3 million square kilometers. Arctic sea ice has fallen below the record low absolute minimum of 4.92 million square kilometers set in 2005 by about 8%, with another 3-5 weeks of the melting season still remaining. Reliable records of sea ice coverage go back to 1979.


Figure 1. Extent of the polar sea ice on August 21, compared to the average for the date from the 1979-2000 period (pink line). Image credit: National Snow and Ice Data Center.

With one third of the Arctic ice cap already gone, and another month of melting to go, we need to consider what effect this will have on weather, climate, and sea level rise. Well, we don't need to worry about sea level rise, since the polar sea ice is already in the ocean, and won't appreciably change sea level when it melts. However, the remarkable melting of the ice cap will likely lead to unusual weather patterns this fall and winter. The lack of sea ice will put much more heat and moisture into the polar atmosphere, affecting the path of the jet stream and the resultant storm tracks. Expect a much-delayed arrival of winter to the Northern Hemisphere again this year, which may lead to further accelerated melting of the ice cap in future years.

Last week, I remarked that the most recent images from the North Pole webcam show plenty of melt water and rainy conditions near the Pole. It turns out that was misleading, since the webcam is on a ship that was headed towards the pole, but had not reached it. There have been rainy conditions at the Pole this summer, and there is some open water there, but this is not uncommon in summer. Shifting ice frequently opens up leads (cracks) with open sea water at the Pole. It was one of these open leads that British swimmer Lewis Gordon Pugh swam in for 18 minutes this July to draw attention to global climate change.


Figure 2. Total rainfall from August 10-22 as estimated by NASA's TRMM satellite.

Midwest flooding
To get an idea of the magnitude of the flooding that has hit the Midwestern U.S. during the past ten days, take a look at the total amount of rain from August 10-22 (Figure 2). We can blame Tropical Storm Erin for the rain in Texas and Oklahoma (up to 11 inches), and for the nine flooding deaths that occurred in those states. However, the unbelievable rain amounts in excess of 20 inches in Minnesota and Wisconsin were primarily due to a frontal system--with the help of some copious moisture pumped northwards by the counter-clockwise circulation around Erin while it spun over Oklahoma.

Tropical update
There are no threat areas in the Atlantic to discuss. Two of our four reliable forecast models, the NOGAPS and ECMWF, are predicting that a tropical depression could form off the coast of Nicaragua on Sunday. The models forecast that this system would move inland over Nicaragua and Honduras by Monday.

I'll have an update on Saturday morning.
Jeff Masters

After Hurricane Dean (sprinter)
Bulldozer trying to clear sand and debris from Norman Manley Highway(Airport Road)
After Hurricane Dean
Findlay Ohio flood (prairieview)
The flood is over, now the cleanup
Findlay Ohio flood

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247. listenerVT
5:55 PM GMT on August 24, 2007
MichaelSTL...(and all)...
I see what you mean about the number of storms.
Yet, in that context, what is the significance of unusual storms, such as the huge cyclone that slammed into Oman this year (first one in 4 or 5 decades there, I believe)?
Are we seeing primarily a shift to fewer, larger storms with tracks heretofore infrequent or unheard of?
How does anyone prepare for catastrophic unknowns?
Will we need a worldwide relief fund dedicated to victims of unpredictable storms?
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246. extreme236
5:56 PM GMT on August 24, 2007
Posted By: listenerVT at 5:54 PM GMT on August 24, 2007.

Historically, when has the "F-word" storm typically formed? Late August?


Well looking back since 2000, the F named storm has formed in late august and early september. (excluding 2005 as it was so abnormal). Also, Felix in 2001 formed on september seventh
Member Since: August 2, 2007 Posts: 19 Comments: 19234
245. latitude25
5:56 PM GMT on August 24, 2007
"Posted By: jphurricane2006 at 5:26 PM GMT on August 24, 2007.

Global warming is a term that is made up to create hysteria"

I agree. More or less the more hysteria you create the more funding you get.

Starting 29 years ago, these same expert climatologists were hysterically predicting a coming ice age. Based on the "fact" that the ice caps were increasing. Predicting that we would not be able to use the St. Lawrence Seaway because it would be a solid block of ice. And anyone that disagreed with them were shouted down.

So, let's start taking measurements of the ice caps when they are the largest, 1970's, right after they predicted a coming ice age based on the "fact" that ice cover was increasing.
Then when they recede, we can claim global warming.

The truth is, we don't know enough about our climate to design reliable models for any of it. This blog is a perfect example of that.
We can't predict with any accuracy El Nino, La Nina, when and if a storm will form, etc.

All global warming models factor in a certain criteria of "facts". One of those "facts" has just been disproven.

All global warming models factor cirrus clouds in as a positive feedback.
The warmer it gets, the more cirrus clouds, that trap more heat, that creates more cirrus clouds.

Cirrus clouds have just been shown to be a negative feedback.

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244. Skyepony (Mod)
5:10 PM GMT on August 24, 2007
See the spin on long range MLB radar from the broad suface low off the FL coast. It's raining:)

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243. extreme236
5:55 PM GMT on August 24, 2007
Posted By: skibrian95 at 5:54 PM GMT on August 24, 2007.

extreme236:

how is an upper level low supressing development? i always thought this meant that the rotation is strong in the upper atmosphere and would help encourage rotation?

can u explain? thx.


the ULL is supressing the development because it is producing higher shear
Member Since: August 2, 2007 Posts: 19 Comments: 19234
241. extreme236
5:54 PM GMT on August 24, 2007
We will have something spin up soon. This could be the quiet before the storm. Right now, we can just sit back, and save our energy for the hype that will soon happen when we get our next invest, which I have a feeling may be that blob near panama
Member Since: August 2, 2007 Posts: 19 Comments: 19234
240. listenerVT
5:49 PM GMT on August 24, 2007
Historically, when has the "F-word" storm typically formed? Late August?
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239. skibrian95
5:52 PM GMT on August 24, 2007
extreme236:

how is an upper level low supressing development? i always thought this meant that the rotation is strong in the upper atmosphere and would help encourage rotation?

can u explain? thx.
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237. MTJax
5:49 PM GMT on August 24, 2007
I think the problem with any formation near FL is the divergence is good but there is no convergence for fuel. Thus DISP. Several good grapics at this link:

http://cimss.ssec.wisc.edu/tropic/real-time/atlantic/winds/wg8conv.html
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236. skibrian95
5:47 PM GMT on August 24, 2007
groundswell...what do you mean "swell"

i would think that with the high over GA bringing easterlies all week that this could be a real good reason for higher waves. not so much the low? i also read a rip tide caution from the melbourne staff the other day predicting a SE wind that was to come through and add to the danger...something about waves coming in at angles to waves already coming in from the east.

anyway...yeah...i think it is the most interesting blob out there...but the experts say nothing is going to happen...i'm trying to figure out why.
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235. lightning10
5:50 PM GMT on August 24, 2007
The dream that So Cal would get moisture from Dean is dieing fast :(.


Satellite shows Hurricane Dean moisture near Cabo which is a little
further south than previous forecasts placed it. 12z model runs not
too bullish on rain chances and will likely be trimming thunderstorms and rain chances and
coverage back for the afternoon package.
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234. Buhdog
5:45 PM GMT on August 24, 2007
Radar is non impressive as rain bands from southwest florida are actually going north and not SE.....

Plus Texas cane....Don't get so excited about that blob out in the Atl..NHC says Shear to the north where it will enter soon. Poof

(No offense)
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233. DallasGumby
5:49 PM GMT on August 24, 2007
Posted By: lakeguy at 5:36 PM GMT on August 24, 2007.

Almost no one on either side of the GW debate is arguing about "pumping enormous amounts of toxic chemicals". The debate is about carbon dioxide, hardly a toxic chemical.

interesting. so which fossil fuel can be burned with only CO2 as the output?


lakeguy, that's a red-herring question, and I'm sure you know it. The global warming debate is all about CO2.
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232. austxanne
5:44 PM GMT on August 24, 2007
jphurricane, I might have added to your list, 'gw is a natural cycle, sped up by humans'

ice core studies show the long cycles...but there was never a population as great in numbers as we have today..that we know about...

anyway...sorry to prolong off-topic chat
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231. skibrian95
5:39 PM GMT on August 24, 2007
mtjax:

that radar is a bit clearer...there is some definite air movement from the south over the pennisula...maybe that is inhibiting...or maybe the tropical moisture can help fuel if there is enough circulation in the low?

anyway...very interesting...i welcome any well versed comments that may be out there....
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230. extreme236
5:43 PM GMT on August 24, 2007
But that blob of convection near panama that the nogaps haves hitting nicaragua as a cyclone is very possible. shear is only 5 kts over the area, and if convection persists, then a low pressure could form.
Member Since: August 2, 2007 Posts: 19 Comments: 19234
229. groundswell
5:39 PM GMT on August 24, 2007
skibrian-I'm watching it-there is already a small swell off the coast..just in time for the weekend. I'm on it.
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228. putintang3
5:22 PM GMT on August 24, 2007
Farmer's Almanac says for the Southeast

September 2007
1st-3rd Scattered showers, a few thunderstorms during Labor Day weekend 4th-7th Hot and oppressively humid with a hurricane threat 8th-11th Heavy thunderstorms along Gulf Coast 12th-15th Fair skies prevail 16th-19th Showery, then clearing 20th-23rd A tropical disturbance brings windy, rainy conditions 24th-27th Squalls sweep across region from west to east 28th-30th Squalls sweep across region from west to east

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227. AinFLA
5:41 PM GMT on August 24, 2007
so I give you a multiple choice question:

Is global warming for real?

A) Yes it is real and humans are to blame
B) No it is not real, it is a made up term
C) Yes it is real and its a natural process
D) Not enough information to go on


jp, we agree. I would take C and D also.

and cudos to Dr. J for correcting himself. Adds to his credibility. Seldom done in the scientific community.

Unfortunately, someone with an agenda will pick up on the uncorrected version and run with it.
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226. extreme236
5:40 PM GMT on August 24, 2007
yes the low pressure is interesting but a ULL is preventing development at this time
Member Since: August 2, 2007 Posts: 19 Comments: 19234
225. skibrian95
5:37 PM GMT on August 24, 2007
extreme....i know it is the "low formerly known as 92L" as mentioned in my first post. LOL (nod to prince). anyway...i'm seeking answers as to why this isn't interesting to anyone...I mean the PhD's aren't excited about it...so there must be a reason.

my gut just thinks it is looking very interesting...it's actually rotating unlike some other "blobs" mentioned
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224. franck
5:28 PM GMT on August 24, 2007
chilliam...think there may be a correlation between the amount of population/human activity in the northern hemisphere and southern hemisphere and the relative melt of the northern and southern caps?
The human population of the northern hemisphere is three times that of the southern hemisphere.
The carbon footprint of each human in the northern hemisphere is three times each human in the southern hemisphere.

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223. MTJax
5:38 PM GMT on August 24, 2007
222. MTJax
5:34 PM GMT on August 24, 2007
About the cold front:

...WAVY COLD FRONT OVER THE MIDWEST/GREAT LAKES PUSHING TOWARD THE
EAST COAST...

THE NAM APPEARS TOO WEAK WITH THE VORT OVER NERN CO AND THE ONE
OVER E-CTRL MT BASED ON WV IMAGERY. THE GFS HAS A STRONGER
DEPICTION WHICH SEEMS REASONABLE.


THE 12Z NAM HAS BKN CONTINUITY VS THE 00Z/06Z RUNS IN NOW
SUGGESTING THAT A COUPLE OF RELATIVELY WEAKER SFC WAVES WILL RUN
NEWD ALONG THE FRONT PUSHING SLOWLY SOUTHEAST OUT OF THE MIDWEST
AND ACR THE GREAT LAKES REGION. THE 00Z/06Z RUNS REFLECTED JUST
ONE WAVE WITH A BIT MORE INTENSITY/ORGANIZATION. THIS ALL SEEMS
RELATED TO THE 12Z NAM SHOWING A MORE SHEARED VORT PATTERN AS THE
MID LVL TROF EJECTS OUT OF THE MS VLY. THE 12Z GFS OVERALL SHOWS
GOOD CONTINUITY WITH THE AMPLITUDE OF THE MID LVL TROF...HOWEVER
IT SHOWS A BIT MORE CONVECTIVE FEEDBACK THAN THE 00Z RUN WITH ITS
VORT PATTERN. AT THE SFC...IT HAS TRENDED A LITTLE WEAKER AND A
LITTLE MORE PROGRESSIVE WITH THE WAVE MOVING FRM THE MIDWEST TO
THE LWR LAKES BY FHR 24. IT HAS ALSO TRENDED A LITTLE SLOWER WITH
THE FRONTAL PASSAGE ACRS THE MID MS/LWR OH VLYS.

THE OVERWHELMING MDL CONSENSUS IS FOR A MID LVL TROF TO EJECT OUT
OF THE MS VLY AND ADVANCE EWD INTO THE GRT LAKES/OH VLY WITH
ESSENTIALLY ONE MAIN SFC LOW EJECTING NEWD ALONG THE
BNDRY....EXCEPT THEY DO SUGGEST A WEAKER LEAD LOW EARLY CROSSING
THE GRT LAKES REGION. THE 06Z/12Z GFS...00Z ECMWF AND 12Z UKMET
SOLNS WITH SUPPORT FRM THE 06Z NCEP MEAN AND THE 09Z SREF-RSM/WRF
MEMBERS ALL LIKE THE IDEA OF ONE FAIRLY WELL-ORGANIZED SFC WAVE
MOVING ALONG THE BNDRY OUR OF THE MIDWEST AFTER FHR 12. THE 12Z
NAM IS A WEAKER OUTLIER AND SHOWS MULTIPLE WAVES WHICH IS A BREAK
IN CONTINUITY TO ITSELF. THE 00Z ECMWF THOUGH IS A STG OUTLIER AND
HAS TOO MUCH CONVECTIVE FEEDBACK. HPC PREFERS A SOLN CAUTIOUSLY
TWD THE 12Z GFS AS THE GFS CONVECTIVE FEEDBACK VORT OVR SRN KS/OK
SHD BE DISCOUNTED...AND THERE SHD BE LESS BAGGINESS IN THE
PRESSURE FIELD OVER THE MIDWEST AT FHR 24...WHICH AGAIN APPEARS TO
BE A FEEDBACK CONSEQUENCE. OTHERWISE THE GFS MASS FIELDS APPEAR
FINE.

ORRISON

MODEL BIASES AT WWW.HPC.NCEP.NOAA.GOV


The FL circulation:
The 06z and 12z sfc maps show the LOW as DISP. Drifting N and W. CNTRL FL in 24h near Ocala.
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221. extreme236
5:35 PM GMT on August 24, 2007
Posted By: skibrian95 at 5:35 PM GMT on August 24, 2007.

This should be long range melbourne radar

does anyone else think this is interesting? I think it does. not a full on rotation yet, but there is an indication of rotation in the scattered echos. far from being powerful. the main map for wunderground does mark an "L" off the FLA east coast.

is there enough energy in the sea and in the air to turn this into a TD in a few days? Maybe a TS if it finally passes to the GOMEX?


That "L" was once associated with ex-92L. It is unlikely the low will develop but it is possible
Member Since: August 2, 2007 Posts: 19 Comments: 19234
220. lakeguy
05:35 PM GMT on Augusti 24, 2007
Almost no one on either side of the GW debate is arguing about "pumping enormous amounts of toxic chemicals". The debate is about carbon dioxide, hardly a toxic chemical.

interesting. so which fossil fuel can be burned with only CO2 as the output?
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218. skibrian95
5:32 PM GMT on August 24, 2007
This should be long range melbourne radar

does anyone else think this is interesting? I think it does. not a full on rotation yet, but there is an indication of rotation in the scattered echos. far from being powerful. the main map for wunderground does mark an "L" off the FLA east coast.

is there enough energy in the sea and in the air to turn this into a TD in a few days? Maybe a TS if it finally passes to the GOMEX?
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217. IKE
12:30 PM CDT on August 24, 2007
Actually...maybe that cold front does make it into the western GOM next weekend....

Found this from the Houston,TX. morning discussion....

"Dewpoints are prognosticated to
fall into the 50s/60s by Saturday morning. Fwiw...the European model (ecmwf) also
brings a front into the state by Thursday night."
Member Since: June 9, 2005 Posts: 23 Comments: 37858
216. austxanne
5:25 PM GMT on August 24, 2007
AinFLA, did you want the names of the astrophysicists or were you sort of wondering about why they made the comment.

One of them is my husband, but I probably won't give his name in a public forum like this...

if you're just wondering why astrophysicists were commenting on global warming or why their opinion mattered...then it's because they're physicists and GW is a complicated and intriguing topic and many of them look at gases in space and the chemical elements...

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215. extreme236
5:30 PM GMT on August 24, 2007
Posted By: clwstmchasr at 5:29 PM GMT on August 24, 2007.

So you are saying that the front is dipping into the GOM? If it does, wouldn't the wind shear only be temporary. Also, if the front hits the GOM, sometimes they can spin up storms?


Yep, fronts can spin up storms because they spawn low pressures, that may be non tropical at first, although they can gather tropical characteristics.
Member Since: August 2, 2007 Posts: 19 Comments: 19234
214. extreme236
5:29 PM GMT on August 24, 2007
I am going to watch the area of nicaragua and see if anything develops there.
Member Since: August 2, 2007 Posts: 19 Comments: 19234
212. extreme236
5:27 PM GMT on August 24, 2007
I hate it when it is slow on this blog lol. Because then we all end up talking about GW and politics lol. Lets watch tropical blobs and non tropical low pressures that may develop lol
Member Since: August 2, 2007 Posts: 19 Comments: 19234
211. Tazmanian
5:28 PM GMT on August 24, 2007
i no that but it may help any systems to re-curve out to sea
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210. IKE
12:26 PM CDT on August 24, 2007
Tropical Weather Outlook...for the planet earth....

Tropical cyclone formation is not anticipated for the next 48 hours.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
209. skibrian95
5:22 PM GMT on August 24, 2007
has anyone looked at the long range melbourne radar? there has been a hint of circulation for days...the Low has not crossed Florida as predicted...but sits off the coast...and numerous showers are starting to fire...though widly scattered.

can anyone explain why there is little interest in this? I still think in my gut that there's a lot more power in that low than given credit...and sitting over the gulf stream...or next week over GOMEX where it is hot and sunny (thus continuing to add energy to the sea) with little shear...might this develop a warm core and tighten up???

sitting here in Orlando, I've been watching all week never convinced that we've seen the last of 92L
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208. chilliam
5:22 PM GMT on August 24, 2007
mississippiwx23 at 4:36 PM GMT on August 24, 2007.
Oh, and as for Antarctic ice, no statistical significant change in the ice has been found to this point. As said earlier, we do not have a long enough record to truely make a statement about it. All we do know is that has increased recently.


Yes but you must say the same for the arctic. We only have accurate measurements since 1979. A 28 year period is less than a drop in the bucket of time. All we do know is that it has decreased recently. You can't brush off the Antarctic increase and focus on the Arctic.

Yes, the planet is warming ... but only writing about the Arctic (which is done ALL the time here) doesn't help the debate, it spurs extremist positions.
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206. AndyD
1:18 PM EDT on August 24, 2007
Fill a small soda jug with water and put it in the freezer. Leave the jug uncapped. See what happens.
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205. IKE
12:25 PM CDT on August 24, 2007
TAZ..that's in Colorado.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
204. Tazmanian
5:23 PM GMT on August 24, 2007
can you say high wind shear they are forcasting a strong cold front could be a cold one too wish may have vary high wind shear for the gulf
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201. extreme236
5:20 PM GMT on August 24, 2007
Something tells me we wont really be watching the gulf this weekend. I am thinking the areas to watch closely are the area near nicaragua, waves off africa, and a non tropical low pressure that could develop if it gains tropical characteristics
Member Since: August 2, 2007 Posts: 19 Comments: 19234
200. Tazmanian
5:14 PM GMT on August 24, 2007
Area forecast discussion
National Weather Service Denver Colorado
257 am MDT Friday Aug 23 2007

by Monday afternoon. Ridging aloft then rebuilds
westward across the Great Basin...resulting in a northwest flow pattern and
opening The Gates to more cooling from the north by the middle of
next week. Latest GFS showing decent front moving into eastern Colorado early
Wednesday with more noticeable cooling and chance of precipitation. Current grids
already refelct this so no changes needed on the out periods.


Area forecast discussion
National Weather Service Pueblo Colorado
355 am MDT Friday Aug 24 2007

GFS continues to indicated a substantial cold
front dropping south across the plains Tuesday night/Wed...with moist
upslope through 700 mb developing by Wednesday afternoon...along with
much cooler temperatures. Current grids have this scenario well
covered...with only minor adjustments made.


i dont no if this will play out right but if it dos this could shut down the gulf for any Tropical Weather Activity
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199. AinFLA
5:17 PM GMT on August 24, 2007
Posted By: austxanne at 4:38 PM GMT on August 24, 2007.
re: sea levels....i was told by 2 astrophysicists that the warming of the oceans will raise the levels...water expands as it warms..


"Why does water expand when it cools?

Water is peculiar. When most substances change from liquid to solid form, they shrink together, become denser, their molecules packed most closely together.

But when water changes from a sloshy liquid to solid ice, it expands, becomes less dense. Which is why ice floats to the top of your Coke, rather than sinking like a stone to the bottom.

At normal atmospheric pressure, molecules usually behave in predictable ways as their temperature changes. Molecules fly apart into a gas when heated, condense into a flowing liquid when cooled, and shrink into a frozen solid when chilled still further. The changes in state parallel changes in energy: from high energy to medium energy to barely jiggling."

austxanne, this is not a flame at you, but who are these two astrophysicist....exactly ???

Does this mean water expands when it warmed and expands when it cooled ??? How do it know ???

This then will finally solve and put to rest todays quandary of GW/Artic melting and flooding vs Antarctic ice expansion .

The answer.....it doesn't matter. Either way we're doomed. I...I...I g.g.g.guess. hmmmm.. Maybe some "scientist" here can clarify it for us. Too much for my little brain.
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198. extreme236
5:16 PM GMT on August 24, 2007
interesting, the Nogaps develops something in a few days so its something to watch and see if something spins up in the area
Member Since: August 2, 2007 Posts: 19 Comments: 19234

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