Frtt BBC: Geimgeislar hafa hrif trjvxt Bretlandi...

dag 19. oktber er vef BBC frttapistill sem nefnist Cosmic pattern to UK tree growth.

Pistillin fjallar um a breskir vsindamenn hafa fundi meiri fylgni milli vaxtarhraa trja og geimgeisla en hita ea rkomu. eir kunna ekki skringu essu en hafa komi me tilgtur. Svo virist vera a trn vaxi hraar egar geimgeislar eru miklir, en samkvmt pistlinum ir a meira skjaykkni. tti einmitt a vera heldur svalara. - Undarlegt.

Ef a er tilfelli a trn vaxi betur egar skja er en slskini kemur a verulega vart. Getur a ekki tt a rhringir trja su ekki eins gur mlikvari hitastig og tali var? a er auvita allt of snemmt a draga lyktanir, en etta kemur neitanlega vart.

Spyr s sem ekki veit. Frlegt verur a fylgjast me essu mli.

British Broadcasting Corporation

Pistillinn byrjar annig:

"The growth of British trees appears to follow a cosmic pattern, with trees growing faster when high levels of cosmic radiation arrive from space.

Researchers made the discovery studying how growth rings of spruce trees have varied over the past half a century.

As yet, they cannot explain the pattern, but variation in cosmic rays impacted tree growth more than changes in temperature or precipitation.

The study is published in the scientific journal New Phytologist.

"We were originally interested in a different topic, the climatological factors influencing forest growth," says Ms Sigrid Dengel a postgraduate researcher at the Institute of Atmospheric and Environmental Science at the University of Edinburgh...

... ...

When the intensity of cosmic rays reaching the Earth's surface was higher, the rate of tree growth was faster.

The effect is not large, but it is statistically significant.

The intensity of cosmic rays also correlates better with the changes in tree growth than any other climatological factor, such as varying levels of temperature or precipitation over the years.

"The correlation between growth and cosmic rays was moderately high, but the correlation with the climatological variables was barely visible," Ms Dengel told the BBC.

Here comes the Sun

Cosmic rays are actually energetic particles, mainly protons, as well as electrons and the nuclei of helium atoms, that stream through space before hitting the Earth's atmosphere.

The levels of cosmic rays reaching the Earth go up and down according to the activity of the Sun, which follows an 11-year cycle...

..."We tried to correlate the width of the rings, i.e. the growth rate, to climatological factors like temperature. We also thought it would be interesting to look for patterns related to solar activity, as a few people previously have suggested such a link," explains Ms Dengel. "We found them. And the relation of the rings to the solar cycle was much stronger than it was to any of the climatological factors we had looked at. We were quite hesitant at first, as solar cycles have been a controversial topic in climatology...""

Lesi meira vef BBC

Humm... Humm... Halo

etta er ekki beinlnis eins og maur hefi tt von .

http://news.bbc.co.uk/earth/hi/earth_news/newsid_8311000/8311373.stm

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New Phytologist
A relationship between galactic cosmic radiation and tree rings
Sigrid Dengel, Dominik Aeby and John Grace
Institute of Atmospheric and Environmental Science, School of GeoSciences, Crew Building, University of Edinburgh, EH9 3JN, UK

ABSTRACT (krkja)

  • Here, we investigated the interannual variation in the growth rings formed by Sitka spruce (Picea sitchensis) trees in northern Britain (55N, 3W) over the period 1961–2005 in an attempt to disentangle the influence of atmospheric variables acting at different times of year.
  • Annual growth rings, measured along the north radius of freshly cut (frozen) tree discs and climatological data recorded at an adjacent site were used in the study. Correlations were based on Pearson product–moment correlation coefficients between the annual growth anomaly and these climatic and atmospheric factors.
  • Rather weak correlations between these variables and growth were found. However, there was a consistent and statistically significant relationship between growth of the trees and the flux density of galactic cosmic radiation. Moreover, there was an underlying periodicity in growth, with four minima since 1961, resembling the period cycle of galactic cosmic radiation.
  • We discuss the hypotheses that might explain this correlation: the tendency of galactic cosmic radiation to produce cloud condensation nuclei, which in turn increases the diffuse component of solar radiation, and thus increases the photosynthesis of the forest canopy.


Sasta frsla | Nsta frsla

Athugasemdir

1 Smmynd: Hskuldur Bi Jnsson

Mjg hugavert. etta er greinilega skyldulesning og vi munum fjalla um hana loftslag.is fljtlega- fann greinina hr: A relationship between galactic cosmic radiation and tree rings

Takk fyrir etta gst.

Hskuldur Bi Jnsson, 19.10.2009 kl. 20:15

2 Smmynd: Gunnar Th. Gunnarsson

Athyglisvert

Gunnar Th. Gunnarsson, 20.10.2009 kl. 00:01

3 Smmynd: gst H Bjarnason

Mn reynsla er s a a er ekki endilega hollt fyrir trjplnturnar a hafa miki slskin og hita, alla vega ekki eins miki og var Suurlandi sastlii sumar. a fylgdu nefnilega miklir urrkar slskininu sem rugglega hefur komi niur vaxtarhraanum. a var greinilegt a grurinn tk kipp ssumars egar mestu urrkarnir voru afstanir.

Dr. Craig Loehle fjallar um etta grein sinni (A 2000-YEAR GLOBAL TEMPERATURE RECONSTRUCTION BASED ON NON-TREERING PROXIES. Energy & Environment Vol. 18, No. 7+8, 2007. Bls. 1050):

"Climate histories are commonly reconstructed from a variety of sources, including ice cores, tree rings, and sediment. There are reasons to believe that tree ring data may not capture long-term climate changes (100+ years) because tree size, root/shoot ratio, genetic adaptation to climate, and forest density can all shift in response to prolonged climate changes, among other reasons (Broecker, 2001; Falcon-Lang, 2005; Loehle, 2004; Moberg et al., 2005). Most seriously, typical reconstructions assume that tree ring width responds linearly to temperature, but trees can respond in an inverse parabolic manner to temperature, with ring width rising with temperature to some optimal level, and then decreasing with further temperature increases (D’Arrigo et al., 2004; Kelly et al., 1994). This response is most likely due to water limitation at higher temperatures, because higher temperatures increase evaporation rates. The result of this violation of linearity is to introduce tremendous uncertainty or bias into any econstruction, particularly for temperatures outside the calibration range...".

Ef geimgeislar hafa fr me sr auki skjafar (Svensmark) gti skringarinnar veri a leita essu samspili sem rugglega er ekki einfalt. Til a dafna vel urfa plnturnar birtu, vatn, nringu, hita og skjl. Ef eitthva af essu vantar, dregur r vaxtarhraanum.

essi pistill BBC er mjg athyglisverur og vekur upp margar spurningar. Eins og alltaf egar eitthva ntt kemur fram rannsknum, srstaklega ef erfitt er a tskra a, verur maur a gta ess a vera ekki of fljtur a draga lyktanir.

gst H Bjarnason, 20.10.2009 kl. 05:17

4 Smmynd: gst H Bjarnason

a a standa reconstruction, en ekki econstruction, nest tilvitnunini grein Loehle.

gst H Bjarnason, 20.10.2009 kl. 05:21

5 identicon

a er margt skrti essum trarbrgum Al-Gore og flaga, eins og hefur fjalla svo vel um. g var a ljka vi stutt blogg um svipa efni, a er a segja, um veri.

a snjar ekki Mosvku

Gullvagninn (IP-tala skr) 20.10.2009 kl. 09:56

6 Smmynd: Hskuldur Bi Jnsson

Gullvagninn -Vinsamleg bending:a borgar sig a lesa greinina ur en fullyrir eitthva um efni hennar.

Annars er g binn a lesa greinina og mun reyna a skrifa frtt um hana kvld loftslag.isog mgulega kjlfari bloggfrslu sama vettvangi um hvaa ingu etta getur haft varandi t.d. proxhitastig (t.d. varandi hokkkylfuna) og geimgeislahugmynd Svensmarks (sjum til). En eins og gst bendir verur maur a gta ess a vera ekki of fljtur a draga lyktanir.

Hskuldur Bi Jnsson, 20.10.2009 kl. 10:44

7 Smmynd: Arnar

Hmm.. er kannski a misskilja en er 'grurhshrif' ekki a a sk 'bindi' hita fyrir nean sig, .e.a.s. endurvarpi hitatgeislun fr jrinni aftur til jarar, og auki annig lofthita?

Mr finnst amk. ekki rkrtt a gera r fyrir v a a hafi veri hlrra heiskru en kaldara ef a er skja.

Arnar, 20.10.2009 kl. 10:50

8 Smmynd: gst H Bjarnason


a er lang farslast a forast a blanda deilum um loftslagsml inn umruna, enda koma au ml essu ekki vi finnst mr.

a er miklu hugaverara a reyna a koma me tilgtur um hva geti veri seyi.

Tilgturnar sem settar eru fram af vsindamnnunum eru auvita bara tilgtur enn sem komi er, jafn gar og tilgtur sem vi gtum varpa fram.

Aalatrii er a skoa allar hugmyndir me opnum hug og blanda ekki hitamlum inn umruna. a er arfi. g hafi minnst Svensmark innan sviga, er a auvita alveg n byrgar, enda er g eins og fleiri rrota. g hefi frekar bist vi "fugri" tengingu vi Svensmark kenninguna, .e. meiri vexti egar geimgeislar eru minni, .e. minna um sk og meiri sl :-)

ndum v me nefinu mean vi huxum mli og veltum v fyrir okkur

gst H Bjarnason, 20.10.2009 kl. 11:01

9 identicon

Grein um slenska sitkagreni og tengsl vi veurfar:

sj: http://www.landbunadur.is/landbunadur/wgsamvef.nsf/0/de4a700574e8909900256f9c004d4836/$FILE/35.pdf

Kveja

lafur Eggertsson

Olafur Eggertsson (IP-tala skr) 20.10.2009 kl. 11:38

10 Smmynd: Gunnar Th. Gunnarsson

sl og urrki, eru betri skilyri fyrir snkjudr plntum, s.s. ls og mak. Slkar vrur draga r vexti trjplantna.

Gunnar Th. Gunnarsson, 20.10.2009 kl. 11:51

11 Smmynd: gst H Bjarnason

Krar akkir lafur fyrir a vsa grein ykkar Gunnhildar.

Mr tti etta mjg hugaver lesning, srstaklega ar sem g vann sem unglingur 3 sumur hj Einari Sm Fossvoginum, en miki Heimrk og vi Rauavatn sem fjalla er um greininni, og svo Haukadal. etta var um 1950.

a kom skemmtilega vart a lesa um stafafuruna. g hafi teki eftir v ar sem g er stundum a dumda mr vi trjplntun a engu var lkara en furan hefi roki upp um veturinn. Mr tti etta undarlegt, en n veit g betur

g minntist slskin, hita og urrk fyrstu athugasemdinni. ar sem g hef veri a planta er mest frjr jarvegur og lynggrur. Efstu lgin eru va blndu vikri, lklega fr Heklu 1947. Plnturnar eru v mjg vikvmar fyrir langvarandi urrkum, amk. mean rturnar liggja grunnt.

Sumari 2008 var nnast ertuyglulirfu-plga, en standi var mun skrra s.l. sumar og akkai g a urrkinum hve lti var um essa vru og mflugur.

gst H Bjarnason, 20.10.2009 kl. 13:08

12 Smmynd: gst H Bjarnason

a tti a standa 1960 en ekki 1950 :-)

gst H Bjarnason, 20.10.2009 kl. 13:09

13 Smmynd: Gunnar Th. Gunnarsson

Slagveursrigning slr verulega blals

Gunnar Th. Gunnarsson, 20.10.2009 kl. 14:56

14 identicon

Sll gst

Varandi rhringi stafafuru og hina hu fylgni vi hl vor (t.d mars) m lklega skra a vegu a frost fari fyrr r jru annig a furan fer fyrr af sta a vori og vex ar af leiandi vel um sumari.

lafur

lafur Eggertsson (IP-tala skr) 20.10.2009 kl. 15:33

15 Smmynd: gst H Bjarnason

Takk fyrir skringarnar lafur.

gst H Bjarnason, 20.10.2009 kl. 21:13

16 Smmynd: Hskuldur Bi Jnsson

Ef einhver hefur huga, er komin inn frtt loftslag.is: Vxtur trja takti vi munstur geimgeisla

Hskuldur Bi Jnsson, 20.10.2009 kl. 21:32

17 Smmynd: gst H Bjarnason

Hugsanlega er g farinn a skilja samhengi aeins betur. g veit ekki hvort mr tekst a koma v til skila, en a m reyna:

pistli BBC stendur ar sem vitna er Sigri Dengel:

The first idea is that cosmic rays ionise gases in the atmosphere, creating molecules around which clouds condense, therefore increasing cloud over. (etta er hluti Svensmark kenningarinnar).

This mechanism is hotly debated among scientists, and evidence for it is weak.

One study published in 2006 suggested it may account for as little as 2% of the variation in cloud cover across the UK. (2% er reyndar miki v samhengi sem Svansmark notar a, ea 1,2 w/m2).

But if it does occur, then an increase in cloud cover and haze would diffuse the amount of solar radiation reaching the trees.

As diffuse radiation penetrates forest canopies better than direct light, it would increase the amount of radiation that plants capture, and increase photosynthesis by trees, boosting growth.

Ef vi gerum r fyrir a kenning Svensmark s rtt og mti skjafari, liggur skringin sustu mlsgreininni. vaknar spurningin: Hvers vegna vaxa essi tr betur egar skja er en heiskrt, og hvers vegna er betri fylgni milli geimgeisla (-> skjafars skv. Svensmark) en hitafars?

a kemur fram greininni a um er a ra greniskg sem planta var Ae skgi Skotlandi ri 1953. Me pistlinum fylgir mynd sem tekin er essum skgi. egar trjm er planta, er yfirleitt planta mjg tt. Til dmis annig a aeins 1,5-2 metrar su milli plantna. Svona skgur verur grarlega ttur egar hann vex upp, srstaklega ef ekkert er grisja. Hann verur svo ttur a slarljsi nr ekki niur milli trjnna og neri hluti eirra verur alveg ber. Aeins trjkrnurnar eru grnar. etta sst vel myndinni hr fyrir nean.

N er tiltlulega auvelt a sj hendi sr a dreift ljs (diffuse) mun auveldara a komast niur milli trjkrnanna en ljs sem kemur r einni stefnu, .e. fr slinni. etta srstaklega vi egar slin er tiltlulega lgt lofti eins og oftast er. Jafnvel trjkrnurnar eru skugga hver fr annarri. Aeins blr himininn nr a lsa upp strsta hluta skgarins. skjuu veri kemur birtan jfn, alls staar fr himninum. Birtan sem kemur fr hvtri skjahulunni er meiri en birtan sem kemur fr blum himninum. Einnig er lklegt a blagrnan nti betur hvtt ljs en bltt. a er essi beina birta sem trn nota ljstillfuninni egar CO2 er breytt srefni og mjlvi, en a hefur auvita afgerandi hfif vxt trjnna.

a er v nokku auskili a tr svona ttum skgi geta vaxi betur egar skja er en heiskrt. Anna gildir egar skgurinn er gisinn og slargeislarnir n a jafnai a skna allt tr. rur hitastigi.

Sitka spruce (Picea sitchensis)

Myndin sem fylgir BBC pistlinum snir hve Ae greniskgurinn er ttur og hvernig aeins efsti hluti trjnna ntur birtunnar.

aag_48118_f3



r grein Henriks Svensmark: Raui ferillin er geimgeislar, en styrkur eirra mtast af breytilegri virkni slar.

Bli ferillin er ttleiki skjahulunnar upp 3,2 km h, skv. skjamyndum r gervihnttum.

essi skring er auvita h v a kenning Svensmarks reynist a einhverju leyti rtt, .e. hvort geimgeislar mti skjafar. Hvort svo er eftir a koma ljs. Hugsanlega tilraunin hj CERN eftir a varpa einhverju ljsi a nstunni.

( svo a hluti kenningar Svensmark komi hr vi sgu, hefur hn ekkert me hnatthlnun a gera essu samhengi).

g vona a mr hafi tekist a lsa v hvernig g skil etta nna.

gst H Bjarnason, 21.10.2009 kl. 06:17

18 Smmynd: Hskuldur Bi Jnsson

Reyndar kom fram greininni a ltil fylgni var milli skjafars og vxt trja - ef g hef skili greinina rtt. annig a vi verum a gera r fyrir a etta su einhvers konar snileg sk ea frekar ma (haze). En g kaupi samt tskringuna na auknum vexti svona ttra skga.

P.S. binn a skrifa sm blogg um trjhringjaggn og hokkkylfuna og vsa umrunni anga ar sem gst vill ekki ra hnatthlnunina hr, sj Er bi a strauja hokkkylfuna?

Hskuldur Bi Jnsson, 21.10.2009 kl. 08:02

19 Smmynd: Hskuldur Bi Jnsson

Hmm, tengillinn virkar ekki: http://www.loftslag.is/?p=3033

Hskuldur Bi Jnsson, 21.10.2009 kl. 08:33

20 Smmynd: gst H Bjarnason

Upphaflega greinin er hr

gst H Bjarnason, 21.10.2009 kl. 09:40

21 Smmynd: Arnar

tlai ekki a draga loftlagsdeilur inn umruna, tengingin vi grurhshrifin var bara s a auki skjafar gti leitt til aukins hita lofthjpnum.

Bara svona pling mti:

Svo virist vera a trn vaxi hraar egar geimgeislar eru miklir, en samkvmt pistlinum ir a meira skjaykkni. tti einmitt a vera heldur svalara. - Undarlegt.

Mr ykir hinsvegar undarlegt a planta sem lifir af mestu ljstillfun vaxi hraar egar beins slarljss ntur ekki vi. Geislunin kemur kannski a einhverju leiti stainn?

Arnar, 21.10.2009 kl. 09:55

22 Smmynd: Emil Hannes Valgeirsson

Sm innlegg. Ef a skiptir mli sambandi vi vxt tra hvenr frost fer r jru snemma vorin, m hafa huga a slrkir vetur norurslum eru oft vsun kulda vegna meiri tgeislunnar og ar af leiandi tti a vera meira frost jru vorin eftir lttskjaan vetur. etta snst svo vi sumrin egar slin er farin a verma.

Emil Hannes Valgeirsson, 21.10.2009 kl. 10:26

23 identicon

Almenna reglan um rhringi og veurfar

Vxtur trja vi skgarmrk (norlg og upp til fjalla) , t.d Svj, Alaska og lpunum stjrnast aallega af sumarhita mean tr sem vaxa t,d mi Evrpu (t.d eik) stjrnast af rkomu vaxtartma, ar hefur hitafar lti a segja um vxtinn (alltaf ngu heitt sumrin). Bretlandseyjum er samspil trjvaxtar lklega mun flknara (samspil margra umhverfistta). slandi rur sumarhitinn mestu, alltaf ng rkoma. t.d (http://www.landbunadur.is/landbunadur/wgsamvef.nsf/8bbba2777ac88c4000256a89000a2ddb/4e2b05245f85560100257487003bf30a/$FILE/Aldur%20og%20%C3%BEroski.pdf)

rhringjaggnin sem notu eru skl, hokkkylfu (Mann ofl) eru flestum tilvikum fr trjm sem vaxa vi skgarmrk (ar sem vxtur er hur sumarhita).

lafur Eggertsson (IP-tala skr) 21.10.2009 kl. 10:47

24 Smmynd: gst H Bjarnason

Sll lafur.

Er ekki svo, a essi fylgni trjvaxtar og geimgeisla/skja sem frttapistill BBC fjallar um, geti aeins tt vi ar sem ttleiki barrskgarins er a mikill, a slarljsi nr ekki niur fyrir efsta hluta trjnna. a er greinilegt myndinni af skginum, sem fylgir BBC pistlinum, a neri 2/3 hlutar trjnna eru nnast alveg berir vegna birtuleysis. (Sj athugasemd #17).

g var a leita netinu grkvld og ttist finna tilvsanir greinar ar sem einmitt var fjalla um a slkum tilvikum yxu trn betur egar ljsi er dreift (skja).

Sj:

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Still, C. J., et al. (2009), Influence of clouds and diffuse radiation on ecosystem-atmosphere CO2 and CO18O exchanges, J. Geophys. Res., 114, G01018, doi:10.1029/2007JG000675.

Abstract:
This study evaluates the potential impact of clouds on ecosystem CO2 and CO2 isotope fluxes (“isofluxes”) in two contrasting ecosystems (a broadleaf deciduous forest and a C4 grassland) in a region for which cloud cover, meteorological, and isotope data are available for driving the isotope-enabled land surface model (ISOLSM). Our model results indicate a large impact of clouds on ecosystem CO2 fluxes and isofluxes. Despite lower irradiance on partly cloudy and cloudy days, predicted forest canopy photosynthesis was substantially higher than on clear, sunny days, and the highest carbon uptake was achieved on the cloudiest day. This effect was driven by a large increase in light-limited shade leaf photosynthesis following an increase in the diffuse fraction of irradiance. Photosynthetic isofluxes, by contrast, were largest on partly cloudy days, as leaf water isotopic composition was only slightly depleted and photosynthesis was enhanced, as compared to adjacent clear-sky days. On the cloudiest day, the forest exhibited intermediate isofluxes: although photosynthesis was highest on this day, leaf-to-atmosphere isofluxes were reduced from a feedback of transpiration on canopy relative humidity and leaf water. Photosynthesis and isofluxes were both reduced in the C4 grass canopy with increasing cloud cover and diffuse fraction as a result of near-constant light limitation of photosynthesis. These results suggest that some of the unexplained variation in global mean ? 18O of CO2 may be driven by large-scale changes in clouds and aerosols and their impacts on diffuse radiation, photosynthesis, and relative humidity.

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Gu, L., D. Baldocchi, S. B. Verma, T. A. Black, T. Vesala, E. M. Falge, and P. R. Dowty (2002), Advantages of diffuse radiation for terrestrial ecosystem productivity, J. Geophys. Res., 107(D6), 4050, doi:10.1029/2001JD001242.

Abstract
Clouds and aerosols alter the proportion of diffuse radiation in global solar radiation reaching the Earth’s surface. It is known that diffuse and direct beam radiation differ in the way they transfer through plant canopies and affect the summation of nonlinear processes like photosynthesis differently than what would occur at the leaf scale. We compared the relative efficiencies of canopy photosynthesis to diffuse and direct photosynthetically active radiation (PAR) for a Scots pine forest, an aspen forest, a mixed deciduous forest, a tallgrass prairie and a winter wheat crop. The comparison was based on the seasonal patterns of the parameters that define the canopy photosynthetic responses to diffuse PAR and those that define the responses to direct PAR. These parameters were inferred from half-hourly tower CO2 flux measurements. We found that: (1) diffuse radiation results in higher light use efficiencies by plant canopies; (2) diffuse radiation has much less tendency to cause canopy photosynthetic saturation; (3) the advantages of diffuse radiation over direct radiation increase with radiation level; (4) temperature as well as vapor pressure deficit can cause different responses in diffuse and direct canopy photosynthesis, indicating that their impacts on terrestrial ecosystem carbon assimilation may depend on radiation regimes and thus sky conditions. These findings call for different treatments of diffuse and direct radiation in models of global primary production, and studies of the roles of clouds and aerosols in global carbon cycle.

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gst H Bjarnason, 21.10.2009 kl. 12:09

25 identicon

g er n ekki viss um a myndin s tekinn skginum Ae aan sem snin koma sem rannsknin fjallar um, en lklega koma au r ttum skgi. ttum skgi er j aeins efri hluti krnunnar a ljstillfa neri hluti krnunnar er "dauur" ess vegna er spurning hvort tmabundinn aukning (mjg ltil) skjahulu vegna geimgeislunar hafi einhver hrif vxtinn vegna ess a hann er ttur?

lafur Eggertsson (IP-tala skr) 21.10.2009 kl. 14:05

26 Smmynd: gst H Bjarnason

Myndirnar eru r greininni ar sem mislegt, sem ekki er frtt BBC, kemur fram.

Sjlfsagt er greinin fyrst og fremst hugaver fyrir leikmenn eins og undirritaan vegna ess a hn vekur msar spurningar. Er fyrst og fremst forvitnileg. Hversu reianleg niurstaan er hef g ekki minnstu hugmynd um.

http://agbjarn.blog.is/users/fa/agbjarn/img/cosmicray-spruce.jpg

gst H Bjarnason, 21.10.2009 kl. 17:05

27 Smmynd: Hskuldur Bi Jnsson

Fyrir hugamenn um geimgeisla (og g veit a gst er srstakur hugamaur um ), er n grein vntanleg um geimgeisla.

a skemmtilega vi essa grein er a hn er birt Atmospheric Chemistry and Physics Discussion - en a er hliartmarit vi sjlft Atmospheric Chemistry and Physics, nema hva a ar eru birtar greinar sem eru ritrningaferlinum og geta lesendur komi me athugasemdir varandi greinina og haft ar me hrif a hvort hn fst birt eur ei (ef g hef skili etta rtt). Enn hafa ekki komi neinar athugasemdir vi greinina.

En hr m lesa greinina eins og hn er nna: Atmospheric data over a solar cycle: no connection between galactic cosmic rays and new particle formationog Abstract:

Aerosol particles affect the Earth's radiative balance by directly scattering and absorbing solar radiation and, indirectly, through their activation into cloud droplets. Both effects are known with considerable uncertainty only, and translate into even bigger uncertainties in future climate predictions. More than a decade ago, variations in galactic cosmic rays were suggested to closely correlate with variations in atmospheric cloud cover and therefore constitute a driving force behind aerosol-cloud-climate interactions. Later, the enhancement of atmospheric aerosol particle formation by ions generated from cosmic rays was proposed as a physical mechanism explaining this correlation. Here, we report unique observations on atmospheric aerosol formation based on measurements at the SMEAR II station, Finland, over a solar cycle (years 1996–2008) that shed new light on these presumed relationships. Our analysis shows that none of the quantities related to aerosol formation correlates with the cosmic ray-induced ionisation intensity (CRII). We also examined the contribution of ions to new particle formation on the basis of novel ground-based and airborne observations. A consistent result is that ion-induced formation contributes typically less than 10% to the number of new particles, which would explain the missing correlation between CRII and aerosol formation. Our main conclusion is that galactic cosmic rays appear to play a minor role for atmospheric aerosol formation, and so for the connected aerosol-climate effects as well.

Hskuldur Bi Jnsson, 21.10.2009 kl. 23:48

28 Smmynd: gst H Bjarnason

Takk fyrir etta Hskuldur.

gst H Bjarnason, 22.10.2009 kl. 05:52

29 Smmynd: gst H Bjarnason

Nokkrar hugaverar krkjur varandi ljstillfun, sk, geimgeisla, rhringi, rkomu og fleira ggti sem gti tengst grri beint ea beint...:

Berkley Lab: Quantum Secrets of Photosynthesis Revealed.
BERKELEY, CA —Through photosynthesis, green plants and cyanobacteria are able to transfer sunlight energy to molecular reaction centers for conversion into chemical energy with nearly 100-percent efficiency. Speed is the key – the transfer of the solar energy takes place almost instantaneously so little energy is wasted as heat. How photosynthesis achieves this near instantaneous energy transfer is a long-standing mystery that may have finally been solved.

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“Response of a Deciduous Forest to the Mount Pinatubo Eruption: Enhanced Photosynthesis” (http://www.as.wvu.edu/biology/bio463/Gu%20et%20al%202003.pdf )
Volcanic aerosols from the 1991 Mount Pinatubo eruption greatly increased
diffuse radiation worldwide for the following 2 years. We estimated that this
increase in diffuse radiation alone enhanced noontime photosynthesis of a
deciduous forest by 23% in 1992 and 8% in 1993 under cloudless conditions....

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http://www.treeringsociety.org/TRBTRR/TRRvol59_1_21-27.pdf

a er langt san menn tengdu vxt rhringja vi slsveifluna, eins og fram kemur hr grein um Ellicott Duglass (1867-1962).

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Proceedings of the Royal Society:

Empirical evidence for a nonlinear effect of galactic cosmic rays on clouds

Galactic cosmic ray (GCR) changes have been suggested to affect weather and climate, and new evidence is presented here directly linking GCRs with clouds. Clouds increase the diffuse solar radiation, measured continuously at UK surface meteorological sites since 1947. The ratio of diffuse to total solar radiation—the diffuse fraction (DF)—is used to infer cloud, and is compared with the daily mean neutron count rate measured at Climax, Colorado from 1951–2000, which provides a globally representative indicator of cosmic rays. Across the UK, on days of high cosmic ray flux (above 3600102 neutron counts h?1, which occur 87% of the time on average) compared with low cosmic ray flux, (i) the chance of an overcast day increases by (194) %, and (ii) the diffuse fraction increases by (20.3) %. During sudden transient reductions in cosmic rays (e.g. Forbush events), simultaneous decreases occur in the diffuse fraction. The diffuse radiation changes are, therefore, unambiguously due to cosmic rays. Although the statistically significant nonlinear cosmic ray effect is small, it will have a considerably larger aggregate effect on longer timescale (e.g. centennial) climate variations when day-to-day variability averages out.

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NASA Earth Observatory:

Global Garden Gets Greener

Leaving aside for a moment the deforestation and other land cover changes that continue to accompany an ever-growing human population, the last two decades of the twentieth century were a good time to be a plant on planet Earth. In many parts of the global garden, the climate grew warmer, wetter, and sunnier, and despite a few El Nio-related setbacks, plants flourished for the most part.....

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New Scientist-Environment

Does rainfall vary with sunspot activity?

THE sun is nearly 150 million kilometres away, but it seems to have Earth's rivers on a leash. The flow of a huge South American river - and thus the rainfall that feeds it - appears to rise and fall with the number of sunspots....

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JGR:

Sunspots, El Nio, and the levels of Lake Victoria, East Africa

An association of high sunspot numbers with rises in the level of Lake Victoria, East Africa, has been the focus of many investigations and vigorous debate during the last century. In this paper, we show that peaks in the ?11-year sunspot cycle were accompanied by Victoria level maxima throughout the 20th century, due to the occurrence of positive rainfall anomalies ?1 year before solar maxima. Similar patterns also occurred in at least five other East African lakes, which indicates that these sunspot-rainfall relationships were broadly regional in scale. Although irradiance fluctuations associated with the sunspot cycle are weak, their effects on tropical rainfall could be amplified through interactions with sea surface temperatures and atmospheric circulation systems, including ENSO. If this Sun-rainfall relationship persists in the future, then sunspot cycles can be used for long-term prediction of precipitation anomalies and associated outbreaks of insect-borne disease in much of East Africa. In that case, unusually wet rainy seasons and Rift Valley Fever epidemics should occur a year or so before the next solar maximum, which is expected to occur in 2011–2012 AD.

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Heavy rainfall tied to sunspot cycles in East Africa
Scientists believe a link observed between sunspots and heavy rainfall can be used to predict disease outbreaks in East Africa.

In a study, published this week (7 August) in the Journal of Geophysical Research – Atmospheres, researchers observed that the occurrence of extreme East African rainy seasons during the twentieth century corresponded with high numbers of sunspots — dark spots on the sun that indicate an increase in the energy output of the sun. ...

gst H Bjarnason, 22.10.2009 kl. 06:36

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Ágúst H Bjarnason
Ágúst H Bjarnason

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agbjarn-hjá-gmail.com

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