Bloggfærslur mánaðarins, ágúst 2011

Grein í Nature: Kenning Henriks Svensmark um áhrif geimgeisla og sólvirkni á skýjafar virðist hafa verið staðfest hjá CERN...

 

cloud-facility-110824.jpg

 

 

Í hinu þekkta ritrýnda vísindariti Nature birtist í dag grein um niðurstöður tilraunarinnar CLOUD hjá CERN í Sviss. Niðurstöðurnar eru mjög jákvæðar fyrir kenninguna um samspil geimgeisla, virkni sólar og skýjafars. 

Til hamingju Henrik Svensmark!

Sjá frétt sem birtist á vefsíðu Nature í dag: http://www.nature.com/news/2011/110824/full/news.2011.504.html

Cloud formation may be linked to cosmic rays

Experiment probes connection between climate change and radiation bombarding the atmosphere.

It sounds like a conspiracy theory: 'cosmic rays' from deep space might be creating clouds in Earth's atmosphere and changing the climate. Yet an experiment at CERN, Europe's high-energy physics laboratory near Geneva, Switzerland, is finding tentative evidence for just that.

The findings, published today in Nature1, are preliminary, but they are stoking a long-running argument over the role of radiation from distant stars in altering the climate....

Meira hér.

---

Úrdrátt úr greininni má lesa hér á vefsíðu Nature: http://www.nature.com/nature/journal/v476/n7361/full/nature10343.html

Role of sulphuric acid, ammonia and galactic cosmic rays in atmospheric aerosol nucleation

 ...

Atmospheric aerosols exert an important influence on climate1 through their effects on stratiform cloud albedo and lifetime2 and the invigoration of convective storms3. Model calculations suggest that almost half of the global cloud condensation nuclei in the atmospheric boundary layer may originate from the nucleation of aerosols from trace condensable vapours4, although the sensitivity of the number of cloud condensation nuclei to changes of nucleation rate may be small5, 6. Despite extensive research, fundamental questions remain about the nucleation rate of sulphuric acid particles and the mechanisms responsible, including the roles of galactic cosmic rays and other chemical species such as ammonia7. Here we present the first results from the CLOUD experiment at CERN. We find that atmospherically relevant ammonia mixing ratios of 100 parts per trillion by volume, or less, increase the nucleation rate of sulphuric acid particles more than 100–1,000-fold. Time-resolved molecular measurements reveal that nucleation proceeds by a base-stabilization mechanism involving the stepwise accretion of ammonia molecules. Ions increase the nucleation rate by an additional factor of between two and more than ten at ground-level galactic-cosmic-ray intensities, provided that the nucleation rate lies below the limiting ion-pair production rate. We find that ion-induced binary nucleation of H2SO4–H2O can occur in the mid-troposphere but is negligible in the boundary layer. However, even with the large enhancements in rate due to ammonia and ions, atmospheric concentrations of ammonia and sulphuric acid are insufficient to account for observed boundary-layer nucleation.

Meira hér.

Hér er um að ræða áfangaskýrslu, og tilraunum ekki lokið. Það er þó vissulega ánægjulegt þegar menn sjá árangur erfiðis síns. Það er þó rétt og skylt að draga ekki neinar ályktanir strax, því fæst orð hafa minnsta ábyrgð...   Það er þó óhætt að segja að þetta sé verulega áhugavert og spennandi...

Var einhver að hvísla, ætli Henrik Svensmark eigi eftir að fá Nóbelsverðlaunin í eðlisfræði? Hver veit?  :-)

                                                                  *****

 

 

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Eldri pistlar um kenningu Henriks Svensmark:

Er jörðin að hitna? Ekki er allt sem sýnist... 1. febrúar 1998.

Merkileg tilraun: Geimgeislar, ský og loftslagsbreytingar
... 1. janúar 2007.

Byltingarkennd kenning dansks vísindamanns skekur vísindaheiminn....
20. feb. 2007.

Nýjar fréttir af Svensmark tilrauninni hjá CERN í Sviss...
8. júní 2009

Ný grein Henriks Svensmark um loftslagsbreytingar af völdum sólar og geimgeisla birt í Geophysical Research Letters í dag 1. ágúst...
1. ágúst 2009.

Prófessor Henrik Svensmark: »Vi anbefalervores venner at nyde den globale opvarmning, mens den varer«...  11. september 2009.

Ný tilraun við Árósarháskóla rennir stoðum undir kennirnar Henriks Svensmarks um áhrif geimgeisla og sólar á skýjafar - og þar með væntanlega á hnatthlýnun eða hnattkólnun...  5. júní 2011.

cloudlogo.jpg

Nokkrar krækjur:

 Cosmic rays get ahead in CLOUD
http://www.rsc.org/chemistryworld/News/2011/August/24081102.asp

Cloud formation may be linked to cosmic rays
http://www.nature.com/news/2011/110824/full/news.2011.504.html

Svensmarks klimateori får rygstød fra Cern
http://ing.dk/artikel/121410-svensmarks-klimateori-faar-rygstoed-fra-cern

Probing the cosmic-ray–climate link
http://physicsworld.com/cws/article/news/46953

Klimaforschung am Teilchenbeschleuniger: Beschreibung der Aerosolneubildung muss revidiert werden
http://www.psi.ch/media/klimaforschung-am-teilchenbeschleuniger-in-german

CERN experiment confirms cosmic ray action
http://calderup.wordpress.com

 

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nature_greinin_kirkby.jpg

 Uppfært 30.8.2011: 

Þegar greinin sjálf er lesin kemur í ljós að hún er alls ekki ný. Hún er send Nature 9. september 2010, og væntanlega skrifuð nokkru áður, eða fyrir meira en ári.
"Received 9 September 2010; accepted 24 June 2011".

CLOUD tilrauninni hjá CERN er þó alls ekki lokið ennþá.

 

Uppfært 1.9.2011:

Prófessor dr. Nir Shaviv skrifar í dag grein hér sem vert er að lesa. Hann er einstaklega vel að sér í loftslagsfræðum, og því vert að veita athygli hvaða skoðun hann hefur.

Greinin byrjar þannig: "The CLOUD collaboration from CERN finally had their results published in Nature (TRF, full PDF), showing that ionization increases the nucleation rate of condensation nuclei. The results are very beautiful and they demonstrate, yet again, how cosmic rays (which govern the amount of atmospheric ionization) can in principle have an effect on climate.

What do I mean? First, it is well known that solar variability has a large effect on climate. In fact, the effect can be quantified and shown to be 6 to 7 times larger than one could naively expect from just changes in the total solar irradiance. This was shown by using the oceans as a huge calorimeter (e.g., as described
here). Namely, an amplification mechanism must be operating.

One mechanism which was suggested, and which now has ample evidence supporting it, is that of solar modulation of the cosmic ray flux (CRF), known to govern the amount of atmospheric ionization. This in turn modifies the formation of cloud condensation nuclei, thereby changing the cloud characteristics (e.g. their reflectivity and lifetime). For a few year old summary, take a look here.

So, how do we know that this mechanism is necessarily working? ...".    [MEIRA]

 Áhugavert myndband með Nir Shaviv er hér. Myndbandið er frá árinu 2010.

 

 

 

 (Er ekki annars merkilegt hve sumir (margir?) hafa miklar áhyggjur af því að
kenningar Svensmarks reynist réttar...   
Auðvitað ættu allir að gleðjast ef svo reynist, því þá væri ljóst að
hlýnun undanfarinna áratuga sé að miklu (mestu?) leyti að völdum náttúrulegra breytinga,
og á því væntanlega eftir að ganga til baka.
Þá geta menn farið að anda rólega aftur, eða anda með nefinu eins og sagt er...).


Gætu geimverur bjargað lofthjúp jarðar með árás...?

 

 

alien_invasion_photoshop_art.jpg

 

 

"Vísindamenn við Penn State-háskólann bandaríska og Geimferðamálastofnunina, NASA, hafa velt fyrir sér hvað gæti valdið árás geimvera á jörðina. Ein tilgátan er að árás yrði gerð til að stöðva hlýnun lofthjúpsins, segir á vefsíðu Fox-stöðvarinnar.

Geimverur gætu ráðist á okkur og „drepið okkur, hneppt okkur í þrældóm og hugsanlega étið okkur“, segir m.a. í skýrslunni. En einnig gætu þær talið að við værum ógn við sólkerfið, rétt eins og við séum ógn við eigin plánetu með því að stuðla að breytingum í lofthjúpnum".

 

Fréttin um þetta hefur birst víða undanfarna daga, og fréttin hér að ofan birtist á vef Morgunblaðsins í morgun..

Sjá til dæmis þessa grein í The Guardian:

Aliens may destroy humanity to protect other civilisations, say scientists

Rising greenhouse emissions could tip off aliens that we are a rapidly expanding threat,
warns a repor
t

Fréttina í The Guardian má lesa hér.

 

Sjálf ritrýnda greinin í Acta Astronoutica:

Would Contact with Extraterrestrials Benefit or Harm Humanity? A Scenario Analysis
Seth D. Baum,1 Jacob D. Haqq-Misra,2 & Shawn D. Domagal-Goldman3
1. Department of Geography, Pennsylvania State University.
2. Department of Meteorology, Pennsylvania State University
3. NASA Planetary Science Division

Acta Astronautica, 2011, 68(11-12): 2114-2129

Sýnishorn úr greininni:

A preemptive strike [from extraterrestrials] would be particularly likely in the early phases of our expansion because a civilization may become increasingly difficult to destroy as it continues to expand. Humanity may just now be entering the period in which its rapid civilizational expansion could be detected by an ETI because our expansion is changing the composition of Earth’s atmosphere (e.g. via greenhouse gas emissions), which therefore changes the spectral signature of Earth. While it is difficult to estimate the likelihood of this scenario, it should at a minimum give us pause as we evaluate our expansive tendencies.

 

 Öll greinin í Acta Astronautica er hér.

 

Þetta er auðvitað mjög mikilvægt framlag í þágu loftslagsvísindanna. Vísindamenn um allan heim munu liggja yfir þessari merku grein næstu daga...  Miklar hávísindalegar umræður hafa birst hér.

Vísindagreinin er einnig aðgengileg sem pdf neðst á þessari síðu.

 

Einn höfunda þessarar merku greinar skrifaði á blogsíðuna PaleBlue.blog í gær:

 

Some important points of clarification

So here’s the thing. This isn’t a “NASA report.” It’s not work funded by NASA, nor is it work supported by NASA in other ways. It was just a fun paper written by a few friends, one of whom happens to have a NASA affiliation.

A while ago, a couple good friends of mine (Seth Baum and Jacob Haqq-Misra) approached me about a paper they were writing, and asked if I wanted to join them on it. The paper was a review of all the different proposed situations for contact with an alien civilization. I didn’t think this was particularly important. After all, I consider the likelihood of contact with an alien civilization to be low. It certainly wasn’t urgent, as I don’t expect this to happen anytime soon. But… it sounded like fun and I decided to join in on it. So we wrote the paper, but I have to admit that Seth and Jacob put in the vast majority of the work on it. One of the scenarios we considered in the review was the possibility that an alien civilization would contact us because they were concerned about the exponential growth of our civilization, as evidenced by climate change. This isn’t an entirely new idea; remember, this was a review effort. Indeed, Keanu Reaves recently played a similar alien in the movie “The Day the Earth Stood Still.” There were lots of other ideas we reviewed, but this was probably the most provocative.

Well, the paper came out a couple months ago. Today, for some reason, The Guardian picked it up, publishing an article about it with the following title: “Aliens may destroy humanity to protect other civilisations, say scientist: Rising greenhouse emissions may tip off aliens that we are a rapidly expanding threat, warns a report for NASA.” That then was picked up by The Drudge Report, with this headline:

“NASA REPORT: Aliens may destroy humanity to protect other civilizations…”

UH OH. Now that is a bit problematic.

So here’s the deal, folks. Yes, I work at NASA. It’s also true that I work at NASA Headquarters. But I am not a civil servant… just a lowly postdoc. More importantly, this paper has nothing to do with my work there. I wasn’t funded for it, nor did I spend any of my time at work or any resources provided to me by NASA to participate in this effort. There are at least a hundred more important and urgent things to be done on any given work day than speculate on the different scenarios for contact with alien civilizations… However, in my free time (what precious little I have), I didn’t mind working on stuff like this every once in a while. Why? Well, because I’m a geek and stuff like this is fun to think about. Unfortunately, there is not enough time for fun. Indeed, I felt guilty at times because this has led to a lack of effort on my part in my interactions with Seth and Jacob. Beyond adding some comments here or there, I did very little for the paper.

But I do admit to making a horrible mistake. It was an honest one, and a naive one… but it was a mistake nonetheless. I should not have listed my affiliation as “NASA Headquarters.” I did so because that is my current academic affiliation. But when I did so I did not realize the full implications that has. I’m deeply sorry for that, but it was a mistake born our of carelessness and inexperience and nothing more. I will do what I can to rectify this, including distributing this post to the Guardian, Drudge, and NASA Watch. Please help me spread this post to the other places you may see the article inaccurately attributed to NASA.

One last thing: I stand by the analysis in the paper. Is such a scenario likely? I don’t think so. But it’s one of a myriad of possible (albeit unlikely) scenarios, and the point of the paper was to review them. But remember - and this is key - it’s me standing for the paper… not the full weight of the National Aeronautics and Space Administration. For anything I have done to mis-convey that to those covering this story, to the public, or to the fine employees of NASA, I apologize.

UPDATE/ADDENDUM: If anyone has further questions about the paper itself, I direct you to contact my good friend and colleague, Seth Baum. Seth is the first and corresponding author on the manuscript, so all queries should first be directed to him.

http://paleblueblog.org/post/9110304050/some-important-points-of-clarification

 

 

Jæja, þá vitum við það...  Sjái menn einhver furðuljós á himninum yfir Reykjavík í kvöld, þá eru það vonandi ekki geimverurnar... Smile

 

 

 

 

 

alien1.jpg

 

 

 

 

 

Sól tér sortna,

sígur fold í mar,

hverfa af himni

heiðar stjörnur.

Geisar eimi

við aldurnara,

leikur hár hiti

við himin sjálfan.

 


mbl.is Gætu geimverur bjargað lofthjúp jarðar með árás?
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Ágúst H Bjarnason

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agbjarn-hjá-gmail.com

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