Jet stream moved northwards 270 miles in 22 years; climate change to blame?
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
Reader Comments
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It is unknown if the jet stream has natural decades-long changes in its path that could account for the observed poleward shift.
I doubt you will answer this but I'll ask anyway. How does this statement from your blog entry above justify the heading on the blog? Either it is established scientifically that "climate change" is causing this or it is not. If it is not, why a header that states that it does? Are climate models considered scientific proof? How many climate models did not find changes that were "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"
It is like having a newspaper heading that says Man kills wife, but the article has no facts to support the headline other than statistics show that husbands are responsible in a majority of wifes deaths.
Interesting supposition though.
JER
I understand. Every day I think about what more can I do for the Environment. I volunteer for Sea Turtle Patrols to help them recover from what man did to almost cause the Kemp's Ridley Sea Turtle go extict some years ago. It's in it's recover stage now but still has a long way to go.
Now that I'm older I really think about the Environment, I can't say I did that when I was younger because nobody ever taught me about it in school. I hope today we are teaching this starting in our Elementary schools all the way through High School. I know my son is far more informed than I was because I'm making sure I teach him about what it and what he can do to help.
At this time, it appears that way...everyone should remain alert throughout the day and act accordingly...no one should be saying they were surprised by any storms that may form today
Good point!
and I'm not saying that humans are causing the warming, just that our impact has been somewhat detrimental to the natural cycles on this planet. especially concerning wildlife.
Never say never!
EXCESSIVE RAINFALL DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
1010 AM EDT THU JUN 05 2008
...VALID 15Z THU JUN 05 2008 - 12Z FRI JUN 06 2008...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...
UPDATE...
ONLY SOME MINOR CHANGES MADE TO THE PREVIOUS EXCESSIVE RAINFALL
POTENTIAL OUTLOOK...WITH A FAIRLY LARGE THREAT AREA CONTINUING TO
BE DEPICTED AHEAD OF THE AMPLIFYING CNTRL PLAINS SYSTEM. WHILE
THE FIRST ORGANIZED CONVECTION AREA HAS PUSHED NEWD INTO THE UPR
LAKES REGION...CONVECTION IS LIKELY TO REDEVELOP ACRS THE SRN TO
CNTRL PLAINS...EXTENDING NWD INTO THE UPR MS VALLEY REGION IN THE
AXIS OF ANOMALOUS MOISTURE FLUX AHEAD OF THE AMPLIFYING MID LEVEL
TROF AND DEEPENING SFC LOW OVR THE CNTRL PLAINS. THIS CONVECTION
WL LIKELY MOVE BACK OVER AREAS THAT RECEIVED HEAVY RAINS OVERNIGHT
FROM ERN NE..ACRS FAR NWRN MO AND INTO IA. ADDITIONAL SHRT TERM
PCPN AMTS OF 1-2" POSSIBLE FROM THE CNTRL PLAINS NEWD INTO THE UPR
MS VALLEY. HEAVY RAIN POTENTIAL ALSO TO CONT IN THE COMMA HEAD
PCPN REGION ON THE WRN SIDE OF THIS AMPLIFYING SYSTEM FROM WRN
NE...FAR NERN CO...ERN WY...WRN SD AND FAR SERN MT.
ORAVEC
PREVIOUS DISCUSSION...
RATHER LARGE SLGT AND MDT AREAS WERE OUTLOOKED OVR THE CNTRL U.S.
GIVEN FCST DVLPMNT OF A SGFNT STORM AS WELL AS SOME UNCERTAINTY TO
THE FCST. THE EXCESSIVE RNFL OUTLOOK WAS DRAWN TO REFLECT ONE
AREA OF SGFNT RAINS EXPECTED ALONG THE E/W ORIENTED FRONTAL BNDRY
EXPECTED TO LIFT NEWD THRU THE UPPER MIDWEST/UPPER MS VLY REGION
AHEAD OF THE SFC LOW AND ASOCTD SHRTWV TROF. SGFNT CNVCTV RAINS
ARE ALSO EXPECTED ALONG AND TO THE LEFT OF THE TRACK OF THE SFC
AND UPPER LVL LOWS. A CONTG INTENSE MSTR FLUX NWD THRU THE CNTRL
U.S. WILL CONTINUE TO SUPPORT THE EVENT WHILE VERY FVBL DIV FLOW
ALOFT AS THE UPPER LVL SYSTEM BEGINS TO TAKE ON A MORE NEG TILT
WITH TIME WILL ENHANCE THE SYNOPTIC SCALE LIFT. COULD SEE QUICK
2.00 INCH RNFL AMTS IN AN HOUR OR TWO JUST ABOUT ANYWHERE IN THE
OUTLOOKED AREA..WITH AMOUNTS APCHG 4.00 TO 5.00 INCHES NOT OUT OF
THE QUESTION OVR SPOTTY AREAS. BEST GUESS FOR AXIS OF MOST SGFNT
RAIN IS ALONG AN AXIS ALIGNED SW/NE ACROSS THE UPPER MS VLY WHERE
MESOSCALE FORCING COULD SLOW THE NWD ADVANCE OF THE E/W MSTR
CNVGNC AXIS RESULTING IN CNVCTV CELLS REPEATING OVR LOCALIZED
AREAS.
KORTY
Link
Looks like Garden City Kansas is about to get hit by one of those right-turning thunderstorms......No tornado warning yet, but looks nasty........
LOL! Although I pretty much agree you have to understand there are a lot of people in this world who lack "common sense"!
I think the world just needs to keep moving forward to reduce pollution and we'll be fine. Regardless we need to take care of our planet.
I'll go take a nap, now.
Try Tambora, Kraktau, St Helens and Pinatubo, for starters. The summer after the Tambora eruption (1815) it snowed in New England in July. The volcanic eruption answer is the easy one...jp, you know as well as the rest of us that the climate is pretty complicated, so denying anything out of hand is a dangerous thing to do.
MESOSCALE DISCUSSION 1230
NWS STORM PREDICTION CENTER NORMAN OK
0138 PM CDT THU JUN 05 2008
AREAS AFFECTED...NWRN TX...SWRN OK
CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY
VALID 051838Z - 051945Z
CONVECTIVE INITIATION APPEARS PROBABLE BY 20-21Z AS HEATING/MIXING
BREAK CAPPING INVERSION ALONG DRYLINE. STRONG SWLYS ON SRN PERIPHERY
OF INTENSE MID-LEVEL JET EJECTING FROM SRN ROCKIES TO THE CNTRL
PLAINS...WILL SUPPORT SUPERCELL DEVELOPMENT INITIALLY WITH ATTENDANT
THREATS FOR LARGE HAIL/DAMAGING WINDS/ISOLATED TORNADOES. A TORNADO
WATCH WILL LIKELY BE ISSUED PRIOR TO 20Z.
RECENT VIS IMAGERY DEPICT CU/TCU INCREASING ALONG DRYLINE...SITUATED
FROM NEAR GAG SWWD TO MAF AS OF 18Z. ALTHOUGH THE MOST SIGNIFICANT
MID-LEVEL FORCING/HEIGHT FALLS ASSOCIATED WITH POTENT HIGH PLAINS
SHORT WAVE WILL REMAIN WELL N OF THE REGION...CONTINUED DAYTIME
HEATING/MIXING WILL LIKELY RESULT IN AT LEAST ISOLATED TO SCATTERED
TSTMS FORMING DURING THE MID/LATE-AFTERNOON. SHEAR/INSTABILITY
PARAMETERS WILL BE QUITE FAVORABLE FOR SUPERCELLS WITH SEVERE
HAIL/WINDS LIKELY. GIVEN THE DEGREE OF MIXING...RELATIVELY HIGH
BASES MAY MITIGATE A MORE SUBSTANTIAL TORNADO THREAT.
NEVERTHELESS...STRONG LOW-LEVEL SLYS WILL SUPPORT POTENTIAL TORNADIC
DEVELOPMENT.
..GRAMS.. 06/05/2008
Looking at profilers and model data, the mid-level flow is too meridional over much of the warm sector - as they mention in their outlook. If I were out chasing, I'd play the warm front in northeastern NE into northern IA where there might be enough southeasterly flow for a few tornadoes...
We could be in for a rather busy season in the coming months once those sst's really warm up.
Check this out from TPC on tropical cyclone development.
THE LATEST CIMSS SAHARAN AIR LAYER ANALYSIS REVEALS
A LARGE AREA OF DUST AND STRONG SUBSIDENCE ASSOCIATED WITH THE
WAVE JUST NOW EMERGING FROM NW AFRICA AND SPREADING AS FAR E AS
40W. THE PRESENCE OF THE SAL SURROUNDING THE NEWEST WAVE TO MOVE
OFFSHORE IS LIKELY INHIBITING CONVECTION OVER THE AREA N OF 11N.
OTHERWISE...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.
$$
KIMBERLAIN
Okay, all I'm going to say is that again, ignoring it would be stupid, denying it worse, but jumping off the other end and killing the economy would be just as bad.
Of course there were warming and cooling trends in the past, and there will trends long after no humans are left to measure them, but IF we're adding to the problem (and I'm convinced that we are, to some greater or lesser degree) we should work on decreasing our impact...a smart man doesn't sh!t where he eats, you know?
Scary, but too true...
You're killing me, jp! LOL
You always find a way to put it in words everyone can understand.
As far as how their system is doing, that discussion is pretty much not meant for a weather blog.
BUT while I'm at it, read notes from OPEC meetings and if it is not Iran then it is Venezuela asking for no production increase or arguing for a production cut. Just asking for it, pushes up crude prices, which helps subsidize their pump price.
Remember when Iran raised pump prices a year or so ago...there were protests and fires lit at gas stations.
So I guess, I would ask, when making a comment along those lines, read up on it, and take some time doing so. It is not an easy topic to know a bit of info on and make informed pronouncements on.
I agree that some of the evidence presented has been crap science, but some of it looks pretty accurate...an issue that could have the effect that this one could shouldn't be ignored. As for spending money for studies and doing the math, we're spending money on things that make me sick, things with no other virtue than making someone with too much money more money...but again, wht the hell...the bottom line is money. Greed will kill a guy, you know?
We've been playing around 100 the past three days or so...thank god the humidity came down some. Today isn't too bad; it feels to be in the mid 80s right now (I just came in from outside). You're in Pearland? I imagine it's pretty thick down there, huh?
Light Rain Fog/Mist
59°F
(15°C) Humidity: 93 %
Wind Speed: NE 7 MPH
Barometer: 30.09" (1020.3 mb)
Dewpoint: 57°F (14°C)
Visibility: 1.50
I try, NEwx...blame it on my central Missourah upbringing...LOL
LOL! That was great!
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