N rannskn: Slsveiflan tengist loftslagsbreytingum.

solar_cycle_h_881165.jpg

Fyrir feinum dgum (16. jl) birtist nokku merkileg frtt hr vef National Science Foundation. Tilefni var rannskn sem kynnt var tmaritinu Journal of Climate sem gefi er t af American Meteorological Society fyrr essum mnu.

Vsindamenn finna tengingu milli slsveiflunnar og loftslags heimsvsu svipaa hrifum El Nino/La Nina. (Scientists find link between solar cycle and global climate similar to El Nino/La Nina). (Sj aths. #5).

"These results are striking in that they point to a scientifically feasible series of events that link the 11-year solar cycle with ENSO, the tropical Pacific phenomenon that so strongly influences climate variability around the world."

etta hljta a teljast nokkur tindi. Frtt National Science Foundation er birt heild hr fyrir nean.

Lesa m um National Science Foundation hr:

The National Science Foundation (NSF) is an independent federal agency created by Congress in 1950 "to promote the progress of science; to advance the national health, prosperity, and welfare; to secure the national defense…" With an annual budget of about $6.06 billion, we are the funding source for approximately 20 percent of all federally supported basic research conducted by America's colleges and universities. In many fields such as mathematics, computer science and the social sciences, NSF is the major source of federal backing. MORE

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Press Release 09-139
Solar Cycle Linked to Global Climate

Drives events similar to El Nio, La Nia

July 16, 2009

Establishing a key link between the solar cycle and global climate, research led by scientists at the National Science Foundation (NSF)-funded National Center for Atmospheric Research (NCAR) in Boulder, Colo., shows that maximum solar activity and its aftermath have impacts on Earth that resemble La Nia and El Nio events in the tropical Pacific Ocean.

The research may pave the way toward predictions of temperature and precipitation patterns at certain times during the approximately 11-year solar cycle.

"These results are striking in that they point to a scientifically feasible series of events that link the 11-year solar cycle with ENSO, the tropical Pacific phenomenon that so strongly influences climate variability around the world," says Jay Fein, program director in NSF's Division of Atmospheric Sciences. "The next step is to confirm or dispute these intriguing model results with observational data analyses and targeted new observations."

The total energy reaching Earth from the sun varies by only 0.1 percent across the solar cycle. Scientists have sought for decades to link these ups and downs to natural weather and climate variations and distinguish their subtle effects from the larger pattern of human-caused global warming.

Building on previous work, the NCAR researchers used computer models of global climate and more than a century of ocean temperature to answer longstanding questions about the connection between solar activity and global climate.

The research, published this month in a paper in the Journal of Climate, was funded by NSF, NCAR's sponsor, and by the U.S. Department of Energy.

"We have fleshed out the effects of a new mechanism to understand what happens in the tropical Pacific when there is a maximum of solar activity," says NCAR scientist Gerald Meehl, the paper's lead author. "When the sun's output peaks, it has far-ranging and often subtle impacts on tropical precipitation and on weather systems around much of the world."

The new paper, along with an earlier one by Meehl and colleagues, shows that as the Sun reaches maximum activity, it heats cloud-free parts of the Pacific Ocean enough to increase evaporation, intensify tropical rainfall and the trade winds, and cool the eastern tropical Pacific.

The result of this chain of events is similar to a La Nia event, although the cooling of about 1-2 degrees Fahrenheit is focused further east and is only about half as strong as for a typical La Nia.

Over the following year or two, the La Nia-like pattern triggered by the solar maximum tends to evolve into an El Nio-like pattern, as slow-moving currents replace the cool water over the eastern tropical Pacific with warmer-than-usual water.

Again, the ocean response is only about half as strong as with El Nio.

True La Nia and El Nio events are associated with changes in the temperatures of surface waters of the eastern Pacific Ocean. They can affect weather patterns worldwide.

The paper does not analyze the weather impacts of the solar-driven events. But Meehl and his co-author, Julie Arblaster of both NCAR and the Australian Bureau of Meteorology, found that the solar-driven La Nia tends to cause relatively warm and dry conditions across parts of western North America.

More research will be needed to determine the additional impacts of these events on weather across the world.

"Building on our understanding of the solar cycle, we may be able to connect its influences with weather probabilities in a way that can feed into longer-term predictions, a decade at a time," Meehl says.

Scientists have known for years that long-term solar variations affect certain weather patterns, including droughts and regional temperatures.

But establishing a physical connection between the decadal solar cycle and global climate patterns has proven elusive.

One reason is that only in recent years have computer models been able to realistically simulate the processes associated with tropical Pacific warming and cooling associated with El Nio and La Nia.

With those models now in hand, scientists can reproduce the last century's solar behavior and see how it affects the Pacific.

To tease out these sometimes subtle connections between the sun and Earth, Meehl and his colleagues analyzed sea surface temperatures from 1890 to 2006. They then used two computer models based at NCAR to simulate the response of the oceans to changes in solar output.

They found that, as the sun's output reaches a peak, the small amount of extra sunshine over several years causes a slight increase in local atmospheric heating, especially across parts of the tropical and subtropical Pacific where Sun-blocking clouds are normally scarce.

That small amount of extra heat leads to more evaporation, producing extra water vapor. In turn, the moisture is carried by trade winds to the normally rainy areas of the western tropical Pacific, fueling heavier rains.

As this climatic loop intensifies, the trade winds strengthen. That keeps the eastern Pacific even cooler and drier than usual, producing La Nia-like conditions.

Although this Pacific pattern is produced by the solar maximum, the authors found that its switch to an El Nio-like state is likely triggered by the same kind of processes that normally lead from La Nia to El Nio.

The transition starts when the changes of the strength of the trade winds produce slow-moving off-equatorial pulses known as Rossby waves in the upper ocean, which take about a year to travel back west across the Pacific.

The energy then reflects from the western boundary of the tropical Pacific and ricochets eastward along the equator, deepening the upper layer of water and warming the ocean surface.

As a result, the Pacific experiences an El Nio-like event about two years after solar maximum. The event settles down after about a year, and the system returns to a neutral state.

"El Nio and La Nia seem to have their own separate mechanisms," says Meehl, "but the solar maximum can come along and tilt the probabilities toward a weak La Nia. If the system was heading toward a La Nia anyway," he adds, "it would presumably be a larger one."

-NSF-

Media Contacts
Cheryl Dybas, NSF (703) 292-7734 cdybas@nsf.gov
Rachael Drummond, NCAR (303) 497-8604 rachaeld@ucar.edu

The National Science Foundation (NSF) is an independent federal agency that supports fundamental research and education across all fields of science and engineering. In fiscal year (FY) 2009, its budget is $9.5 billion, which includes $3.0 billion provided through the American Recovery and Reinvestment Act. NSF funds reach all 50 states through grants to over 1,900 universities and institutions. Each year, NSF receives about 44,400 competitive requests for funding, and makes over 11,500 new funding awards. NSF also awards over $400 million in professional and service contracts yearly.


Sasta frsla | Nsta frsla

Athugasemdir

1 Smmynd: Jn Magnsson

akka r fyrir etta. a er frlegt a sj essa niurstu sem sjlfu sr er samrmi vi margt anna sem bendir til ess a hnattrn hlnun s ekki af mannavldum heldur vegna nttrulega sveiflna sem vi hfum ekki hrif . er a merkilegt mia vi niurstur sem koma fram bk Nigel Lawson fyrrum fjrmlarherra Bretlands "An appeal to reason" a ekki hefur veri um hlnun a ra essari ld og hljasta ri sem hefur mlst var ri 1936 a v er mig minnir.

a er srkennilegt mia vi au takmrkuu vsindi sem liggja a baki manngerri hlnun jarar a forustumenn helstu inrkjanna nema Kna og Indlands skuli tla a leggja trilljna skatta heimsbyggina grundvelli ess sem g hef kalla plitsk veurfri.

Jn Magnsson, 19.7.2009 kl. 12:57

2 Smmynd: Emil Hannes Valgeirsson

g akka fyrir etta einnig. Mig grunar stundum a hrif slarinnar hita jarar felist a einhverju leyti hrifum hennar hafi, t.d. flugri Golfsstraumur me flugri slvirkni. Kannski f g a einhverntma stafest.

En t af v sem Jn segir verur a askilja tvennt. Annarsvegar langtmahlnun af mannvldum og svo sveiflur sem eiga sr sta af nttrulegum vldum, t.d. slinni, en hvort tveggja getur tt sr sta sama tma.

Einnig m g til me a leirtta misskilning hj Jni me hljasta ri (1934) en ar var bara um a ra Bandarkin en ekki heiminn allan. 1998 er yfirleitt tali a hljasta heiminum, NASA er me 2005, en bi rin voru miklu hlrri en 1934, nema menn lumi einhverjum njum sannleik.

Emil Hannes Valgeirsson, 19.7.2009 kl. 16:33

3 Smmynd: Fannar fr Rifi

a sst n alveg hrna frni,egar slblettir eru lgmarki a a er enn skaflar niur mijar hlar lkt v sem hefur veri.

Fannar fr Rifi, 19.7.2009 kl. 20:43

4 identicon

akka r fyrir essa frslu gst.

g renndi yfir textann sem var essari frttatilkynningu fr NSF (gat ekki fundi greinina sjlfa) og snist etta allt saman gtlega merkilegt. Vildi spyrja ig beint: Telur a essi rannskn s eitthva a gefa skyn a loftlagsbreytingar r sem tengdar hafa veri aukningu grurhsalofttegunda s vegna essara sk. solar cycle?

Mr snist t.d. ingmaurinn fyrrverandi misskilja essa tilvitnun na me eim htti. g s a segir a alls ekki - en vildi einvrunga f hreint a g vri ekki a misskilja.

Greinin snist mr vera tengja "solar cycle" vi ENSO (a er El Nino-hrif) en ekkert er minnst a solar cycle skri miklu loftlagsbreytingar sem hafa veri tengdar vi gruhsalofttegundir. Leirttu mig ef g hef rangt fyrir mr.

Magns Karl Magnsson (IP-tala skr) 19.7.2009 kl. 22:40

5 Smmynd: Sveinn Atli Gunnarsson

g tel ekki a hgt s a lesa t r essari frslu (ea greininni a sem gst vitnar ) a hnattrn hlnun geti ekki veri af mannavldum. g tel a hr s veri a rannsaka einn af eim ttum (eins og ENSO-fyrirbrin) sem magna (ea draga r) loftslagsbreytingum. Sumir ttir nttrunni er s.s. annig a eir magna hrif loftslagsbreytinga (t.d. El-Nino) en arir draga r (t.d. La-Nina og minni styrkur slar). a vi fum betri vitneskju um samband essara hluta sem gst skrifar um hr frslunni, er ekki hgt a segja a essi niurstaa segi neitt til um a hlnunin geti ekki veri af mannavldum eins og Jn lyktar hr a ofan. ar fyrir utan eru hljustu r heiminum fr v mlingar hfust um 1880 flest nr okkur tma. Eins og sj m t.d. hr og hr. a eru engin r fr 4. ratugnum topp 20 listanum yfir hljust r heiminum samkvmt v...

PS. g vil einnig koma me rlitla athugasemd vi inguna hr, svona af v g vil hafa etta rtt

Vsindamennirnir telja sig hafa fundi tengingu milli slsveiflunnar og hnattrnna loftslagsbreytinga svipa og hrifa El Nino/La Nina. (Scientists find link between solar cycle and global climate similar to El Nino/La Nina).

tli a vri ekki rttara a ora etta svo:

Vsindamenn finna tengingu milli slsveiflunnar og loftslags heimsvsu svipaa hrifum El Nino/La Nina.

a er ekki tala um Global Climate Change - heldur aeins Global Climate, sem er svipa og hgt er a segja um El Nino og La Nina sem hafa hrif loftslag heimsvsu, en hafa sjlfu sr enginn bein hrif r hnattrnu loftslagsbreytingar sem vi upplifum nna, nnur en hugsanlega a magna ea draga r hrifunum.

Mbk.

Sveinn Atli Gunnarsson, 19.7.2009 kl. 22:44

6 Smmynd: gst H Bjarnason

Magns. g held a fari ekki milli mla a veri er a fjalla um hrif 11 ra Schwabe sveiflunnar veurfar. Ekki langtmahrif og v ekki hitahkkunina sem var sust ld. a er frekar a menn horfi til langtmasveifna slinni varandi slkt, en a er ekki veri a fjalla um a essari grein.

Menn hafa mest beint sjnum snum a lengri sveiflum, svo sem 22-ra Hale sveiflunni, 88 ra Gleissberg sveiflunni ea 210 ra Suess sveiflunni. Sj t.d. hr http://pubs.usgs.gov/fs/fs-0095-00/fs-0095-00.pdf. Listi yfir nokkrar greinar um svipa er hr: http://agbjarn.blog.is/blog/agbjarn/entry/908785/

a sem er ntt ea frekar venjulegt essari grein er (held g) a eir virast vera a greina hrif 11-ra sveiflunnar, sem margir hafa tali illmgulegt vegna dempanda hrifa hins mikla massa sem er sjnum. a hafa fleiri tali sig hafa fundi slkt samband milli 11 ra sveiflunnar og veurfars. ar meal er Dr. Will Alexander sem hefur veri a tengja rkomu og vatnsmagn m Suur Afrku vi 11-ra slsveifluna.

gst H Bjarnason, 19.7.2009 kl. 23:27

7 Smmynd: gst H Bjarnason

Svatli. a er auvita erfitt a a nkvmlega svo llum lki. g geri mr vel grein fyrir v og er a stan fyrir v a g setti ensku setninguna breytta innan sviga strax fyrir aftan inguna. Einnig foraist g a a anna r greininni af smu stu.

gst H Bjarnason, 19.7.2009 kl. 23:35

8 Smmynd: gst H Bjarnason

Nlegt efni fyrir sem gaman hafa af svona mlum, en algerlega n byrgar bloggarans :

Grein The Independent

Dr. David Whitehouse
The missing sunspots: Is this the big chill?
http://www.independent.co.uk/news/science/the-missing-sunspots-is-this-the-big-chill-1674630.html

Very Low Solar Activity Causes Some to Speculate About a New Dalton Minimum
http://www.associatedcontent.com/article/615061/very_low_solar_activity_causes_some.html?cat=58

Climate Research News
Quiet Sun: Who Saw it Coming?
http://climateresearchnews.com/2009/04/quiet-sun-who-saw-it-coming/

N er a spurning, hvers megum vi vnta? Ekki veit g a...

gst H Bjarnason, 19.7.2009 kl. 23:54

9 Smmynd: Sveinn Atli Gunnarsson

g tta mig v a erfitt er a a svona greinar og teksta. essu tilviki er um hreina vibt a ra ingunni, sem vert vri a leirtta sjlfri frslunni, svo enski tekstinn komi ar fram. ar af leiandi vildi g koma framfri vinsamlegri bendingu varandi etta.

Sveinn Atli Gunnarsson, 19.7.2009 kl. 23:55

10 Smmynd: gst H Bjarnason

Sveinn Atli. g breytti essu nna morgunsri. Takk fyrir bendinguna.

gst H Bjarnason, 20.7.2009 kl. 05:43

11 Smmynd: gst H Bjarnason

Takk fyrir innliti Jn. a er rugglega margt sem vi eigum lrt. svo a essi kvena grein fjalli fyrst og fremst um skammtmahrif slar veurfar, er essi rannskn rugglega mikilvgt innlegg til a efla skilning okkar.

gst H Bjarnason, 20.7.2009 kl. 05:57

12 Smmynd: sds Sigurardttir

Takk krlega fyrir mig. g stal myndinni og nota sem toppmynd hj mr.

sds Sigurardttir, 20.7.2009 kl. 09:56

13 Smmynd: gst H Bjarnason

hugavert!

Sj eftirfarandi grein sem birtist gr (20. jl) The New York Times:

New York Times

http://www.nytimes.com/2009/07/21/science/space/21sunspot.html?pagewanted=1&_r=1&em

Is the Sun Missing Its Spots?

r greininni:

"“...It’s been as dead as a doornail,” David Hathaway, a solar physicisthe Sun perked up in June and July, with a sizeable clump of 20 sunspots earlier this month.Now it is blank again, consistent with expectations that this solar cycle will be smaller and calmer, and the maximum of activity, expected to arrive in May 2013 will not be all that maximum. at NASA’s Marshall Space Flight Center in Huntsville, Ala., said a couple of months ago...."

MEIRA...

gst H Bjarnason, 21.7.2009 kl. 19:49

Bta vi athugasemd

Ekki er lengur hgt a skrifa athugasemdir vi frsluna, ar sem tmamrk athugasemdir eru liin.

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Ágúst H Bjarnason
Ágúst H Bjarnason

Verkfr. hjá Verkís.
agbjarn-hjá-gmail.com

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Aðeins málefnalegar athugasemdir, sem eiga ótvíætt við efni viðkomandi pistils, og skrifaðar án skætings og neikvæðni í garð annarra, og að jafnaði undir fullu nafni, verða birtar. 

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