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
Bulldozer trying to clear sand and debris from Norman Manley Highway(Airport Road)
The flood is over, now the cleanup
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And my point is "we" weren't around during most of your post. In fact if you condensed the time the Earth was formed to the present into a one year period, where Jan 1 was the day the earth was created and Dec 31 at midnight is current day and time. Man arrived about 30 seconds ago...
When the earth was ice free in the past what was that blamed on? I'm sure the dinosaurs weren't driving gas powered engines...
Ohh and how or what started the Ice Age and how did it end?
You surely aren't serious!
It's folks that say rather silly things such as 'dinosaurs didn't drive SUV's' that make the rest of those that are skeptical have a bad name.
Furthermore have you ever heard of Milankovitch cycles?
TWC was talking about some non tropical low in the atlantic somewhere. they said they are watching it to see if it can get tropical characteristics. im still trying to figure out where this low pressure is lol. there are a few low pressures so im trying to figure out which one there talking about
Me too, i think its the one off the US East Coast
It was to illustrate a point... Sometimes it takes a ridiculous metaphor to get a point across..
I've heard of the cycles and it was actually my point. A million years ago human were not here and we had ice ages and warm periods. Couldn't we be in a natural warm cycle?
I really didn't mean to get the whole GW debate ramped up again...
excluding the low off Virginia and the low west of the Azores, do you think a tropical storm will be named before the end of the month?
I think so. With that convection near panama, which is in a favorable enviroment would be to me the most imminent feature, as it may develop before it hits nicaragua
excluding the low off Virginia and the low west of the Azores, do you think a tropical storm will be named before the end of the month?
No.
Well according to cyclone phase diagrmas from CMC and GFS a low pressure area in the vicinty of the 1003 mb low is expected to become a shallow warm-core system i.e. subtropical system.
The one in the central north atlantic west of the azores? if that is the one you are talking about then i think the only way it really could develop is as a subtropical system similiar to vince
What an interesting system.
Jesus, study physics before you make comments about the physics of a process
- water expands when heated duh - But I don't think it will be enough to raise sea levels significatly
water contracts when cooled until the ice crystals form at which time it expands as air is trapped in the crystal matrix.
Water doesn't expand because of air trapped in the crystal matrix. It reaches maximum density at around 4 degrees C, and as it gets colder, it expands again. When ice crystals form, the angle between the two Hydrogen bonds goes from about 105 degrees (when liquid and gas) out to 120 degrees due to the attractions between the Oxygen and Hydrogen atoms as they get close to one another to form the hexagonal crystal. Therefore, the molecules take up more space in crystalline form.
why do you say that ike? but this time include the low pressures near the azores and the virginia coast. about 3 models develop something near nicaragua
Just don't think they'll be any named system until September...models aren't picking up on anything that's a near certainty like Dean was.
There's only 7 days until September.
Couldn't we be in a natural warm cycle?"
More than likely.
It wasn't that long ago that Great Britain almost put France out of the wine/grape business.
Then it got too cold for grapes to grow in Great Britain, and France recovered.
Posted By: extreme236 at 3:12 PM CDT on August 24, 2007.
why do you say that ike? but this time include the low pressures near the azores and the virginia coast. about 3 models develop something near nicaragua
Just don't think they'll be any named system until September...models aren't picking up on anything that's a near certainty like Dean was.
There's only 7 days until September.
yes, but as you said, there are 7 days left. a lot can change from now to then lol
so perhaps two subtropical systems? lol
Well according to the models, they can be wrong and they can be right but the only way to know is by watching.
hmm... less cirrus = drought? I'd rather have the heat.
Posted By: IKE at 8:15 PM GMT on August 24, 2007.
Posted By: extreme236 at 3:12 PM CDT on August 24, 2007.
why do you say that ike? but this time include the low pressures near the azores and the virginia coast. about 3 models develop something near nicaragua
Just don't think they'll be any named system until September...models aren't picking up on anything that's a near certainty like Dean was.
There's only 7 days until September.
yes, but as you said, there are 7 days left. a lot can change from now to then lol
If I'm wrong, I won't be like SK and not admit it on here. LOL.
1)Nogaps
2)cmc
3)emcwf
4)perhaps ukm
4 models hinting at development. 4 models hinted at dean developing as well...
not even a intersting blob in the Atlantic
-_-
does anyone have a link to the history of tropical storm Erin. Its origination and track before landfall near Port Aransas. All info will be appreciated. Homeschool Project.Thanks!
Try checking wikipedia.org-they have some good tropical info
wow im bored
not even a intersting blob in the Atlantic
JLPR look harder! lol. we have some sfc lows that are spinning around. we got a blob near panama. but yes, its boring waiting for them to either form, or not form lol
Posted By: plylox at 8:30 PM GMT on August 24, 2007.
does anyone have a link to the history of tropical storm Erin. Its origination and track before landfall near Port Aransas. All info will be appreciated. Homeschool Project.Thanks!
Try checking wikipedia.org-they have some good tropical info
YES that is the info I need. THANK YOU!!!
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