Jet stream moved northwards 270 miles in 22 years; climate change to blame?

By: Dr. Jeff Masters , 4:11 PM GMT on June 05, 2008

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Climate change is forcing the jet stream higher and closer to the pole in both the Northern and Southern Hemisphere, according research published this April in the journal Geophysical Research Letters. In their paper, "Historical trends in the jet streams", researchers Cristina Archer and Ken Caldeira of Stanford's Carnegie Institution of Washington analyzed data from 1979-2001, and found that the Northern Hemisphere jet stream moved northward at approximately 125 miles per decade (270 miles during the 22-year period of the study). The jet moved higher by 5-23 meters during this period, and the wind speeds decreased by about 1 mph. Archer and Caldeira's study confirms other research showing a poleward movement of the jet stream in recent decades (Fu et al., 2006; Hu and Fu, 2007). All of these changes are consistent with the behavior of the jet stream predicted by global warming theory. For example, Lorenz and DeWeaver (2007) found poleward shifts of the jet stream by 2100 in the forecasts of 15 climate models used to formulate the "official" word on climate, the 2007 Intergovernmental Panel for Climate Change (IPCC) report. However, the authors were careful not to say how much of this shift in the jet stream was due to natural causes versus human-caused climate change. It is unknown if the jet stream has natural decades-long changes in its path that could account for the observed poleward shift.


Figure 1. The jet stream is located where the strongest winds at the top of the troposphere are found (35,000-45,000 feet high, 200-300 mb in pressure).

Archer and Caldeira note that "These changes in jet stream latitude, altitude, and strength have likely affected, and perhaps will continue to affect, the formation and evolution of storms in the mid-latitudes and of hurricanes in the sub-tropical regions." They don't specify what these changes might be. There is very little research that has been done suggesting how changes in the jet stream might affect hurricane formation and strength. One effect we may begin to see in coming decades is a reduction and/or delay in the number of hurricanes that recurve northward out to sea. Recurvature occurs when a hurricane begins to "feel" the westerly winds of the jet stream. As the jet stream continues to move northward and weaken as the globe warms, we can expect that hurricanes moving though the Caribbean will be less likely to recurve, resulting in more hurricane strikes in Mexico and Central America. Unfortunately, the quality of the Atlantic hurricane database for non-U.S. landfalls is not very good, and it will be several decades before we will be able to tell if the number of hurricane landfalls in Mexico and Central America is increasing due to a poleward shift in the jet stream.

References
Fu, Q., C. M. Johanson, J. M. Wallace, and T. Reichler (2006), Enhanced mid-latitude tropospheric warming in satellite measurements, Science, 312, 1179, doi:10.1126/science.1125566.

Hu, Y., and Q. Fu (2007), Observed poleward expansion of the Hadley circulation since 1979, Atmos. Chem. Phys. Disc., 7, 9367.9384.

Lorenz, D. J., and E. T. DeWeaver (2007), Tropopause height and zonal wind response to global warming in the IPCC scenario integrations, J. Geophys. Res., 112, D10119, doi:10.1029/2006JD008087.

Jeff Masters

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1064. pearlandaggie
11:01 PM GMT on June 07, 2008
1062. LOL!

Anthropogenic Global Whining! :)
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1063. moonlightcowboy
5:56 PM CDT on June 07, 2008
WUhoo, Pottery! Got some wet stuff, finally! WTG!
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1062. KEEPEROFTHEGATE (Mod)
10:55 PM GMT on June 07, 2008
so be it
Member Since: July 15, 2006 Posts: 174 Comments: 54634
1061. Drakoen
10:54 PM GMT on June 07, 2008
1041. Weather456 10:25 PM GMT on June 07, 2008
1033. SpaceThrilla1207 6:15 PM AST on June 07, 2008

You are so right.....but Maria was also a Cape verde hurricane....but it still illustrates your points....many many storms in 2005 were close to land...look at where Katrina, Rita and Wilma originated. I have a video of a large SAL Outbreak in July 2005. Here's a still image from July 21 2005:


Thats some hellish dust.



1045. moonlightcowboy 10:27 PM GMT on June 07, 2008
Thanks, Drakoen. No worries, Levi.


No problem.
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1060. Weather456
6:51 PM AST on June 07, 2008
1056. pottery 6:49 PM AST on June 07, 2008

Good to see you all got some needed rain.
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1059. pearlandaggie
10:50 PM GMT on June 07, 2008
1058...you'd better watch what you post in here buddy lest the whining begin again! :)
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1058. KEEPEROFTHEGATE (Mod)
10:47 PM GMT on June 07, 2008
just a reminder gas prices set to rise on mon to 142 144 barrel 150 by july 220 by christmas
Member Since: July 15, 2006 Posts: 174 Comments: 54634
1057. pearlandaggie
10:49 PM GMT on June 07, 2008
wassup, pottery60?
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1056. pottery
6:44 PM AST on June 07, 2008
Good evening, all.
Some decent, and welcomed, showers over the past 12 hrs. Now, a new wave is passing through. A large area of cloud/unsettled weather covers the Islands.
10 mins ago, some rumblings from the south/east, so more rain on the way too.
Its been a damp day for a change.
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1055. SpaceThrilla1207
10:42 PM GMT on June 07, 2008
I don't like all this BS about global warming and gas prices/fuels, etc. Let's get back to the tropics.

I think we'll see a lot of CV fish storms this year personally.
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1053. pearlandaggie
10:36 PM GMT on June 07, 2008
1036. you're not talking about me, are you? i'm not mad...i was outside spreading mulch in the flowerbeds.

i think you're gonna find that "alternative" will come to mean something other than just solar/wind/bio. i believe coal gasification will have a major impact on our lives in the future. with the new carbon capture technology, coal can be used to generate electricity without the soot or CO2 of the past. i think nuclear will also become an "alternative" energy source in the future. both of these technologies have the potential to provide a lot of power without the huge footprint of solar or wind farms.
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1052. KEEPEROFTHEGATE (Mod)
10:34 PM GMT on June 07, 2008
only thing we got going for us is shift from netural conditions to el nino conditions by late oct early nov should pretty much shut down what ever firers up in the mid season time frame from 15 jul till 15 of sept ya get get a lot of storms in those 60 days
Member Since: July 15, 2006 Posts: 174 Comments: 54634
1051. SpaceThrilla1207
10:26 PM GMT on June 07, 2008
Yeah, I remember the local news in mid-late July around the time of the humongus saharan dust outbreak after Dennis and Emily were all gone and why no more major hurricanes were developing. They said it was because of the saharan dust's extention west. That was the first time I learned about saharan dust's impact upon the TATL.

That was the quiet period, between mid-late July and mid August, except for a couple weak fish storms there was nothing during that time frame in '05 due to the large dust outbreak.

Also the main reason that TD10 didn't form in the CATL until east of the Bahamas. If TD10 had formed in the CATL without all that dust and dry air, maybe TD10 would have developed and gone north and became a fish storm like Irene. Possible the heavy SAL is what killed new orleans in that standpoint.
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1050. moonlightcowboy
5:36 PM CDT on June 07, 2008
1048. I think you're spot-on, Keeper.
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1049. moonlightcowboy
5:34 PM CDT on June 07, 2008
Photobucket

Monthly mean MSLP May 2008 - The way the B/A high is setting up indicates that CV storms could curve towards the eCONUS, FL and the GOM, instead of mostly tracking due west like canes did last year when the high ridged much further west. Also, the high anchored far easterly, now, out by the Azores is not as strong as last year's high, but still quite large covering an expansive area dipping into the tATL and as far swest as Trinidad. High pressure contours in the swATL are still about 1014mb. Those reasons make me think that we're just running a bit behind climatologically. That's probably really more normal than what we'd consider "normal" for this time of year. Indeed, I think it's unfolding, but pretty much as it should. We'll see mid-June and early July disturbances; but not likely very strong. Then, in the latter part of July things will get cranking. It still wouldn't surprise me though to see something get sneaky and surprise us all before then.
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1048. KEEPEROFTHEGATE (Mod)
10:31 PM GMT on June 07, 2008
anything goes mlc
no place safe everybody gets a fair chance this time around
Member Since: July 15, 2006 Posts: 174 Comments: 54634
1047. stormlvr
10:28 PM GMT on June 07, 2008
There sure is a tremendous amount of potential this year. So much so that I feel a little guilty getting excited about it. Sure hope its not all realized.
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1046. KEEPEROFTHEGATE (Mod)
10:26 PM GMT on June 07, 2008
year of the cv demons
Member Since: July 15, 2006 Posts: 174 Comments: 54634
1045. moonlightcowboy
5:25 PM CDT on June 07, 2008
Thanks, Drakoen. No worries, Levi.

It's just really beginning to look like a serious season is in front of us. That all important position of that high is going to be the tell-all. And, right now, it's not looking very favorable, really for anywhere in the Caribbean, GOM or the eCoast. Ugh!
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1044. Weather456
6:26 PM AST on June 07, 2008
KEEPEROFTHEGATE,

gteetings
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1043. KEEPEROFTHEGATE (Mod)
10:20 PM GMT on June 07, 2008
g'even all
Member Since: July 15, 2006 Posts: 174 Comments: 54634
1042. STORMTTOP
10:21 PM GMT on June 07, 2008
systems indicate a nice hurricane in Mid July .. maybe More...
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1041. Weather456
6:17 PM AST on June 07, 2008
1033. SpaceThrilla1207 6:15 PM AST on June 07, 2008

You are so right.....but Maria was also a Cape verde hurricane....but it still illustrates your points....many many storms in 2005 were close to land...look at where Katrina, Rita and Wilma originated. I have a video of a large SAL Outbreak in July 2005. Here's a still image from July 21 2005:

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1040. moonlightcowboy
5:22 PM CDT on June 07, 2008
Levi, much respect, and I'm not totally disagreeing with you, but the "high" has been considerably further south in the past several weeks and SST's have been considered cooler. This explains some of the WES feedback and how the ITCZ movement is associated with warmer SST's.


MYSTERY of the ITCZ
What Keeps the ITCZ North of the Equator?

It is a long-standing mystery that the ITCZ stays north of the equator over the Atlantic and eastern Pacific Oceans despite that the annual-mean solar radiation at the top of the atmosphere is symmetric with respect to the equator. This article reviews recent progress that has shed new light on this old puzzle.

(excerpt in part)...The ITCZ problem thus involves a circular chicken-and-egg argument. The ITCZ stays north of the equator because SST is higher; and the SST is higher north because the ITCZ stays there. The positive WES feedback is at the center of this circular argument. In a coupled ocean-atmosphere model, the WES feedback destabilizes the symmetric climate, leading to an asymmetric steady state with a single ITCZ on only one side of the equator (Xie and Philander 1994). A condition for this spontaneous development of latitudinal asymmetry is the equatorial upwelling that prevents the ITCZ from forming at the equator. This necessary condition thus explain why climatic asymmetry only develops over the eastern Pacific and Atlantic where the equatorial upwelling is observed.
(Complete article here.)
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1039. Levi32
2:23 PM AKDT on June 07, 2008
1038. Drakoen 2:22 PM AKDT on June 07, 2008

Hm yeah I suppose that does make sense. Sorry MLC
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1038. Drakoen
10:22 PM GMT on June 07, 2008
1035. Levi32 10:18 PM GMT on June 07, 2008
1032. moonlightcowboy 2:14 PM AKDT on June 07, 2008 Hide this comment.
Yes, Adrian, agreed; but, the ITCZ moving northwards is an indication that waters are becoming warmer and will continue to warm.

Not really......the ITCZ movement has more to do with the ridging/Bermuda High that is in place, influencing the ITCZs' natural movement.


The SST's do factor into where the ITCZ is located as the ITCZ follows the area of highest sea-surface temperatures in the CATL.
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1037. GainesvilleGator
10:11 PM GMT on June 07, 2008
From Fire831rescue (comment #1023) - "I'm all for alternatives, but I don't think we're going to find a viable solution in my lifetime."

I am so sorry to hear that you are terminally ill. I hope you make it thru this Christmas.

With Crude, Natural Gas, & Coal getting increasingly more expensive, alternative energies aren't looking so pie-in-th-sky as they did just a mere five years ago. Keep in mind that we don't have to completely do away with fossil fuels, we just need to hold demand flat to 20% less by using alternative energy sources. Nuclear power should come back in a big way. Vehicles are likely to use some combination of gas, electricity, & hydrogen.

Americans need a high threshold of pain to change & that is where we are at now. I do expect a lot of developments to occur that will help relieve us from the current energy crises we are in.


Member Since: September 11, 2005 Posts: 4 Comments: 745
1036. fire831rescue
10:18 PM GMT on June 07, 2008
Hmmm. Guess I've made people mad in here with my rants... LOL. Oh, well. Can't make everyone happy.
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1035. Levi32
2:17 PM AKDT on June 07, 2008
1032. moonlightcowboy 2:14 PM AKDT on June 07, 2008 Hide this comment.
Yes, Adrian, agreed; but, the ITCZ moving northwards is an indication that waters are becoming warmer and will continue to warm.


Not really......the ITCZ movement has more to do with the ridging/Bermuda High that is in place, influencing the ITCZs' natural movement.
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1034. Weather456
6:14 PM AST on June 07, 2008
ABOVE NORMAL SEA SURFACE
TEMPERATURES ARE STILL TOO COOL OVER MUCH OF THE TROPICAL
ATLANTIC FOR TROPICAL CYCLONE DEVELOPMENT


1031. Drakoen 6:12 PM AST on June 07, 2008

Well unfortunately, those SSTs are climbing fast.
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1033. SpaceThrilla1207
10:09 PM GMT on June 07, 2008
I mean, when's the last time we've seen a cape verde hurricane in July? Bertha was the only one that I can think of? And don't bring up Emily...Emily was NOT a cape verde hurricane, she was a CATL hurricane. In order to be classified as a CV hurricane you have to be a TD by 40W and a hurricane by 60W, Emily was neither.

Actually Irene was the only CV storm that made it to hurricane status of the year 2005 believe it or not. Saharan dust the major factor on why they didn't develop until later.
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1032. moonlightcowboy
5:11 PM CDT on June 07, 2008
Yes, Adrian, agreed; but, the ITCZ moving northwards is an indication that waters are becoming warmer and will continue to warm.
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1031. Drakoen
10:11 PM GMT on June 07, 2008
We'll get those SST's up there sooner or later and it will be interesting when the ITCZ lifts further north as the SST'S are very high within the location of the ITCZ.

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1030. HIEXPRESS
6:09 PM EDT on June 07, 2008
Thought we still would need to process some oil for the Asphalt, yielding gasoline etc. which somebody will have to burn, but in Trinidad & Tobago, I guess they just dig it up.
Typical Product Yield from Simple Distillation
Definitions of Petroleum Products and Other Terms
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1029. hurricane23
6:08 PM EDT on June 07, 2008
Indeed ive already mentioned this a few days ago along with the continued warm of atlantic sst's and SAL being a non-issue its a recipe for an above normal season.A few days ago forcaster Kimberlian at TPC spoke about the below normal windshear in the eastern atlantic.

Here is what she had to say...

CIMSS SHEAR ANALYSES AS WELL AS CIRA EXPERIMENTAL
GENESIS PRODUCTS SHOW MUCH LOWER-THAN-AVERAGE VERTICAL WIND
SHEAR S OF ABOUT 18N E OF 55W...A TREND WHICH HAS CONTINUED
SINCE AT LEAST MAY. IN FACT...THE AREA AVERAGE SHEAR ACROSS THE
TROPICAL ATLANTIC IS LESS THAN 20 KT...WHEN IT SHOULD BE MUCH
CLOSER TO 30 KT. DESPITE THE EARLIER-THAN-NORMAL DYNAMIC
POTENTIAL OVER THE TROPICAL ATLANTIC...ABOVE NORMAL SEA SURFACE
TEMPERATURES ARE STILL TOO COOL OVER MUCH OF THE TROPICAL
ATLANTIC FOR TROPICAL CYCLONE DEVELOPMENT.

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1028. SpaceThrilla1207
10:03 PM GMT on June 07, 2008
Is it possible that we could beat Bertha (1996) in CV hurricane for the both earliest and most intense for the first half of July?
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1027. moonlightcowboy
5:00 PM CDT on June 07, 2008
...I hear ya, 456 and StormW. When the wave train starts coming this year, it's liable to be one of those long ones, several cars...and seemingly, no caboose! The islands and CONUS, no doubt will feel some great impacts!
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1026. fire831rescue
10:01 PM GMT on June 07, 2008
By the way, Hi to everyone!!! Hehe.
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1024. Weather456
5:50 PM AST on June 07, 2008
1020. moonlightcowboy 5:46 PM AST on June 07, 2008

I would not be suprise if 2008 produced the Atlantic's earliest cape verde tropical cyclone (not necessarily a hurricane, but a TS also). Dust continues to be below normal levels of previous years and below normal wind shear over the past 31 days continues.
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1023. fire831rescue
9:54 PM GMT on June 07, 2008
I'm all for alternatives, but I don't think we're going to find a viable solution in my lifetime.
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1022. fire831rescue
9:38 PM GMT on June 07, 2008
Pearland, I personally think that in order to use alternative energy, the first question that needs to be asked is: Is the source we're looking for feasible. The second question should be: Is it something that would be economical or would it cost more to produce that it's worth. If we take a look at E-85, we see these questions answered. 1st: It cost more to produce one gallon of ethanol from corn than the energy it produces. 2nd: Yes it works but look at answer number 1. Problems with solar are that the sun sets and you have nothing to charge the cells. Problem with wind power is the wind isn't a constant, reliable source. Some people have proposed wave action as a viable source. But then you have to look at the long term on that one. Maintenance being on of the problems. Salt water corrodes metals. Also, electricity and water aren't best friends. Throw salt in the mix and you've got problems. Yes, we have many great ideas for alternative energy but we just don't have the technology to make these sources a reliable and efficient way to produce energy. In my opinion, until the technology is developed, we really have no other choice. We can tout alternatives all day long but until we come up with a better mouse trap, so to speak, we're stuck using fossil fuels. The quest for other energy sources is not a new thing. We've been looking since before my time.
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1021. hurricane23
5:48 PM EDT on June 07, 2008
Indeed this is just a feature in the upper levels and chances at development are near zero.Ive saved a few close-up animations for you to view.

Give it a view seconds to load.

GIF 1
GIF 2
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1020. moonlightcowboy
4:42 PM CDT on June 07, 2008
456. With the ITCZ making the move north, the twaves are likely to have more of a chance at spinning something up. SST's will be there, and much will be riding on shear and dust. I still think we're gonna see an early spinner from there. Thanks.
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1019. Weather456
5:34 PM AST on June 07, 2008
1016. pearlandaggie 5:32 PM AST on June 07, 2008

Greetings
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1018. Weather456
5:31 PM AST on June 07, 2008
The ITCZ has move a good degrees north since 48 hrs ago, mainly due to decreased ridging induced by the passage of a frontal trough over the West-Central Subtropics. LINK
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1017. HIEXPRESS
5:18 PM EDT on June 07, 2008
I'd take some more rain in Florida- I'd even settle for a few clouds. Pattern good for East coast inshore fishing late night to mid morning as it's cool & the land breeze counters the easterly flow & it gets calm.
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1016. pearlandaggie
9:32 PM GMT on June 07, 2008
afternoon, 456!
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1015. pearlandaggie
9:28 PM GMT on June 07, 2008
1013. i suspect the medium-range energy future of this country will begin to depend more and more on coal, but not in the ways we've used coal in the past. i suspect the bridge to future technologies like high-efficiency solar will be paved with coal...just an educated guess.
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1014. Weather456
5:26 PM AST on June 07, 2008
good afternoon all
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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.

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