Radiazione Solare Totale questa sconosciuta. Possibile?

Posted on 27 novembre 2012
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Si parla di TSI (Total Solar Irradiation) e della sua misura ad opera del programma satellitare della NASA. La TSI è importante perché rappresenta quella che viene definita solitamente costante solare. Benché infatti sia soggetta ad oscillazioni che seguono l’andamento dei cicli solari, queste sono abbastanza piccole da essere ritenute non significative, di qui la decisione di considerarla costante e di mettere da parte il forcing solare nel cercare di interpretare le dinamiche del clima.

Molte volte abbiamo detto che la TSI è solo una parte del cosiddetto forcing solare e neanche la più importante, ma non è su questo che torneremo oggi.

Il programma satellitare della NASA che si occupa di queste misure si chiama SORCE. I sensori sono a bordo dell’omonimo satellite che orbita attorno al Pianeta a 645km di altezza fornendo, secondo quanto si legge sulle pagine della NASA “state-of-the-art measurements of incoming X-ray, ultraviolet, visible, near-infrared, and total solar radiation“.

Il 22 novembre scorso su Tallbloke è stato pubblicato un post molto interessante che vi inviterei a leggere. L’autore avanza l’ipotesi che la misura della TSI, pur accurata, non rispecchi quello che viene effettivamente ricevuto dal Pianeta, ma reastituisca un valore condizionato da quanto accade tra la quota di 645km e il limite superiore dell’atmosfera restituendo una perdita netta di radiazione ultravioletta e un guadagno netto di radiazione visibile e radiazione infrarossa, come da figura sotto.

http://tallbloke.files.wordpress.com/2012/11/bb-spectrum.png

Insomma, un satellite che misura la TSI sotto il limite superiore dell’atmosfera, le cui dinamiche alle quote superiori potrebbero avere effetti non trascurabili su quello che avviene in termini di energia ricevuta. Quell’energia così importante per i calcoli sul bilancio radiativo, sull’effetto serra, sul riscaldamento globale, sulla sensibilità climatica e, in definitiva su tutto quello su cui si discute forse con i numeri sbagliati da parecchio tempo a questa parte.

Qualcuno ha un’idea?

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26 Replies to "Radiazione Solare Totale questa sconosciuta. Possibile?"

  • Maurizio Rovati
    27 novembre 2012 (15:43)
    Reply

    Mah, un’idea no, ma un dubbio sì.

    All’inizio scrive:

    The Sun’s Photosphere has an effective temperature of 5,778 K.

    Therefore, the Photosphere’s Irradiance Spectrum should be equal to the Irradiance Spectrum of a Blackbody at 5,778 K.

    Cioè: la fotosfera ha una temperatura effettiva di 5778 kelvin

    Quindi lo spettro dovrebbe essere UGUALE a quello di un corpo nero di pari temperatura.

    Io ho sempre letto che lo spettro solare è SIMILE a quello di un corpo nero, non UGUALE.
    Questo perchè l’emissione dei gas non segue esattamente quella del corpo nero ideale, specialmente quando sono rarefatti come nell’atmosfera solare (cromosfera e corona).

    Per questo, se ho ragione, essendo sbagliate le premesse…

  • Alessio
    27 novembre 2012 (17:21)
    Reply

    Mah certo, il tipo e’ sulle stesse lunghezze d’onda di Capogna e i suoi magici pannelli fotovoltaici. Perle si saggezza snocciolate con gran disinvoltura:

    “the Photosphere’s Irradiance Spectrum should be equal to the Irradiance Spectrum of a Blackbody at 5,778 K” Gia’, e (tralasciando l’approssimazione che la temperatura di emissione si possa definire a 5778K) gli assorbimenti nella corona solare?

    “The atmosphere above 645 km emits a lot of visible light.” !?!?

    “It’s a dirty little secret that climatologists definitely don’t want you to know.” Aye mate. Una volta ho pure sentito che un tizio ha visto canguri nei boschi del Trentino.

    “Clouds absorb UVB and *emit visible light* ..” aridaje nuvole luminescenti.

    “The atmosphere transforms energy.” bravo “Unfortunately, these variable atmospheric absorption lines [in the solar spectrum] seem to have been written out the official scientific script.” Non e’ che se lui non le sa le cose, allora tutti non le sanno eh. Fa su un casotto con quelle Fraunhofer lines e non si capisce a che gli serve citarle se non per gonfiare il mumbojumbo di pseudo-scienza che ci mette dentro (se proprio, quelle sono linee di emissione per lo piu’ dell’atmosfera solare ed un cip di ossigeno atmosferico…che centra col suo discorso? )

    “Climatology’s “Energy Budget” science is wrong.

    Climatology’s “Greenhouse Effect” science is wrong.

    Climatology’s “Global Warming” science is wrong.”

    Se vabbe’. Avanti un altro. Guido, sara’ anche un periodo di magra per caldazze, freddi o ghiacci agonizzanti, ma ‘ste robe proprio….

    • Guido Guidi
      27 novembre 2012 (17:27)
      Reply

      Alè, ma ti pare che gli abbiamo dato ragione? Dico, sarà anche un periodo di magra con la Cop18 ridotta ad una megariunione di condominio, ma fai come Bombolo, se te lo dico me meni, se non te lo dico me meni uguale…dimme che me voi menà!
      gg

      • Alessio
        27 novembre 2012 (22:26)
        Reply

        Guido non si tratta di Bombolo. Ci si scherza su per non piangere (e scrivo castronerie pure io nella foga, le linee sarebbero state di assorbimento, no emissione come ho scritto), ma la questione e’ poco da ridere. Chiaramente il trasferimento radiativo non e’ il tuo forte, senno’ su quel post non ci avresti speso le righe che ci hai speso. E non lo avresti definito “molto interessante” (e fai venire il sospetto che tu sia alla ricerca di “materiale-scomodo-e-controverso-si-sa-mai-in-intanto-lo-pubblico)”. Perche’ non lo e’. E’ non solo profondamente scorretto, ma lo e’ pure faziosamente (resto su un registro non scurrile, ma leggi le perifrasi per come le direi a tu per tu), sparando robe del tipo

        “Climatology’s “Energy Budget” science is wrong.
        Climatology’s “Greenhouse Effect” science is wrong.
        Climatology’s “Global Warming” science is wrong.”

        basate su profonda ignoranza e oltretutto in malafede. So gia’ che mi risponderai del tipo “eh ma io ho invitato a leggerlo cosi’ la gente si fa un’idea ed infatti vedi che lo hanno bocciato”. Su Tallbloke quell’accozzaglia di imbecillita’ l’hanno postata ben 2 volte perche’ la prima, ahime’, e’ pure passata inosservata. E ora te ce la propini una terza. Ora che te lo hanno bocciato anche gli amici e non solo io che te voglio mena’, aggiungici per favore in fondo “bene abbiamo appurato che e’ una serie di stronzate. Buona notte”

        • Guido Guidi
          28 novembre 2012 (09:10)
          Reply

          Beato te che hai capito tutto Alè…
          gg

          • Maurizio Rovati
            28 novembre 2012 (09:38)

            No, non ha capito tutto, capisce quello che vuole lui.
            Tu Guido hai probabilmente commesso un errore nel dare risalto a questo post, può capitare, lui ne ha commesso uno più grosso, come succede quando si va in giro con tutta la Verità nelle saccocce.

  • franco zavatti
    27 novembre 2012 (17:47)
    Reply

    Sono un po’ perplesso: gli effetti descritti ci sono senz’altro ma non mi è chiaro quanto pesano sulla distribuzione spettrale dell’irraggiamento solare. Io credo che pesino molto poco e che siano “annegati” nell’errore.
    Qui i dati osservati sembrano avere differenze di irraggiamento notevoli che poi si compongono in un risultato finale con una banda di errore che comprende le fluttazioni (sì, sono sistematiche in quanto trasferiscono energia dall’UV al visibile e all’IR) descritte da Cullen.
    C’è un altro articolo di Krivova, Solanki1,Schmutz (A&A 529, A81, 2011, DOI: 10.1051/0004-6361/201016234) in cui la TSI viene prodotta utilizzando i dati del magnetometro MDI di SOHO (posizionato nel punto lagrangiano L1, a 1.5 milioni di km in direzione del Sole e quindi ben al fuori dell’atmosfera terrestre), i dati di PMOD e i dati di TIM/SORCE senza trovare particolari differenze se non qualcosa legato alla perdita di sensibilità di MDI (soho è in orbita dal 1995 e comincia ad essere un po’ vecchiotto). Nel confronto tra TIM/SORCE, PMOD e il loro modello, gli autori scrivono :”A very good agreement between the model and both TIM/SORCE and PMOD data was found, with the linear correlation coefficient lying above 0.98 in both cases …” quindi gli effetti descritti da Cullen non dovrebbero essere troppo visibili.
    Non conta molto nel contesto generale ma non fa una buona impressione la figura dello spettro in giornate serene e nuvolose, presa da un sito commerciale, in cui la griglia orizzontale non coincide con le “tacche” del grafico e in cui si visualizzano densità molto diverse da quelle dell’esosfera/magnetosfera.

  • donato
    27 novembre 2012 (20:56)
    Reply

    Il post di Cullen mi dà l’idea di uno di quei sermoni in cui si dicono un sacco di cose senza dimostrarne alcuna e si affastellano una serie di fatti che, presi singolarmente, non significano nulla, ma accostati l’uno all’altro sembra che delineino un quadro logico (che, però, non lo è). Detto in altri termini assomiglia molto ad una di quelle teorie che vogliono le piramidi costruite da civiltà aliene perché la loro conformazione sembra avere una qualche correlazione con la costellazione di Orione, perché i lati e le facce si trovano in certe proporzioni, ecc. ecc..
    Questa prima impressione è stata confermata dal commento di F. Zavatti e, soprattutto, dai dati che possono reperirsi al link da lui fornito e all’articolo citato. L’esame dei dati citati da F. Zavatti mi ha convinto del fatto che i fenomeni di trasformazione energetica di cui parla Cullen sono reali, ma da un punto di vista quantitativo spostano di poco (forse nulla) i termini della questione: come dice F. Zavatti si perdono nel rumore delle osservazioni (basta dare un’occhiata ai compositi desunti dalle osservazioni dei singoli satelliti per rendersene conto).
    Proprio dalle operazioni da cui sono stati desunti i diagrammi compositi della TSI, però, ho potuto rendermi conto che la stima (di ciò si tratta, infatti) di questa grandezza è piuttosto problematica. I valori desunti dai dati satellitari relativi alla fine degli anni settanta e quelli degli ultimi esperimenti differiscono notevolmente, in particolare la TSI è diminuita con il passare degli anni. Probabilmente questa diminuzione è frutto di errori sistematici degli strumenti di misura utilizzati e del loro miglioramento tecnologico, però mi rende piuttosto perplesso. Una cosa positiva che ho potuto notare, inoltre, riguarda le metodiche di omogeneizzazione utilizzate: si basano sul confronto dei risultati di diversi strumenti di misura di cui si conoscono le caratteristiche, proprio quello che manca in altre circostanze.
    La concordanza tra le misure del radiometro di SOHO e quelle degli altri strumenti di misura, infine, dovrebbe tagliare definitivamente la testa al toro.
    Per chiudere un sentito ringraziamento a F. Zavatti per averci fornito dati in grado di dirimere gli aspetti salienti della questione.
    Ciao, Donato.

  • Tim Cullen
    28 novembre 2012 (17:45)
    Reply

    Perhaps it is better to say that solar radiation should be SIMILAR to the radiation of a blackbody at 5778 K. No problem.

    The diagram [originally from Wikipedia] clearly shows that TSI is not from a blackbody at 5778 K because there are clear absorption losses and emission gains.

    http://malagabay.files.wordpress.com/2012/11/extraterrestrial-total-solar-irradiance_analysis.jpg

    However, the evidence presented in the article clearly shows that TSI is transformed within the Earth’s atmosphere:

    Some TSI is transformed above 645 km – before it reaches the SORCE satellite.
    Some TSI is transformed below 645 km – after it reaches the SORCE satellite.

    Therefore,
    1) SORCE is not measuring “top of atmosphere” TSI.
    2) SORCE is not measuring “bottom of atmosphere” TSI.

    The evidence presented clearly shows that hydrogen in the Exosphere interacts with the Solar Wind and generates X-Rays which SORCE will interpret as being emitted by the Sun. Therefore, overall, we don’t really know what SORCE is measuring.

    http://malagabay.files.wordpress.com/2012/11/sorce-transformed-tsi.jpg

    The spectrum for a “cloudy day” shows UVA being transformed into visible light and infrared radiation. Therefore, the SORCE TSI spectrum [especially of infrared radiation] cannot be used to calculate a theoretical “greenhouse effect” at the “bottom of atmosphere”.

    Overall, these observations invalidate the standard “energy budget” because the solar wind and TSI energy transformations are not included in the “energy budget”.

    Unfortunately, these energy transformations require further study before they can be quantified. The “cloudy day” spectrum and the “airglow” phenomenon clearly indicate that they should not be simply dismissed as trivial and just ignored.

    http://malagabay.files.wordpress.com/2012/11/earths-airglow.jpg

    If SORCE measured Total Solar Irradiation and Total Terrestrial Radiation [at altitude of 645 km] then we could start to understand [holistically] the overall “energy budget” for the atmosphere below 645 km.

    • Maurizio Rovati
      29 novembre 2012 (12:57)
      Reply

      Welcome Tim and thank you.

      I can not hold a technical discussion with you but I hope that others will do so with the necessary expertise.
      My opinion is that the data received from scientific instruments could be interpreted in good faith mistakenly maybe due to lack of knowledge or deliberately manipulated in one sense or another.
      The first hypothesis falls within the normal scientific practice of experimental verification, and the second lies in the political fight.
      Personally I hope that everything stays whithin the field of science. Unfortunately, I know that often this is not the case and that scientists, as human beings, are not impartial, but at least they should try to be more impartial then lawyers … :-)

      Best regards.

      M.

  • Alessio
    29 novembre 2012 (23:04)
    Reply

    Tim,

    thanks for joining the conversation (Guido, wow. You’re getting international!).

    Straight to some of the (many) problems embedded in your reasoning. In your post you keep on holding on the mystery of the mismatch between the blackbody emission curve at 5778K (do you know where this exact temperature comes from?) and the observed SI spectrum. Funny, there is not a single mention to the solar atmosphere and its composition. I guess you’re aware of the many atmospheric physics books out there. The ones I know all clearly show that the spectrally-resolved Solar Irradiance is not expected to follow the pure blackbody curve at a single (approximate) temperature. And this is due to the complex structure of the solar atmosphere and to the emission/absorption processes in it, shaping the irradiance spectrum that reaches the outer boundaries of the Earth’s atmosphere. In particular the UV part of the spectrum owes it’s lower emission temperature to the non-isothermal profile of solar atmosphere. Now, what’s wrong with this explanation of what you see as a (conspiracy-linked) mismatch?

    Where does then the “missing” UV go? Where does the magic VIS comes from? You state that the Earth atmosphere (also above 600km) emits in the solar spectrum (a lot apparently) and so would be the case also for the cloud layers in the troposphere. So from space the Earth is basically a wee glowing sun? Wow, I bet we also give some of the light to the Moon! Also, you’re free to rewrite the quantum mechanics as it pleases you, and I’d be delighted to know what kind of not-clearly-understood process would allow a cloud layer at temperatures around 250K to emit a non negligible amount of radiation in the short-wave spectrum. (did you notice that the plot that should support this folly is normalised irradiance? Surely you know what it means for the shape of your spectral distribution. An hint: it doesn’t support your claim).
    Among the rest, I think you also have not clear the difference between emission and scattering of electromagnetic radiation.

    The Fraunhofer lines: really I don’t see your point in adding them to the soup. These are absorption lines and most of them belong to the Sun’s atmosphere. The few of them of atmospheric origin, are well know like the Oxygen absorption lines in the visible. So what?

    I’m going to skip the rest of the mumbojumbo Gish-gallop about ionized particles, magic energy transformations and conspiracy.

    Finally, given the -how to say it nicely?- “unconventional” scientific basis not supporting your claims, I find quite blunt..actually frankly insulting and surely pathetic the “everything and everyone are wrong” ending of your post.

    So long.

    Now to Guido: it’d really be nice to hear whether you have any personal ideas about Tim’s post, beyond the monosyllabic comments and jokes for which you’ve already shown your competence.

    • Guido Guidi
      30 novembre 2012 (16:16)
      Reply

      Alessio you and Tim both showed a level of knowledge of this matter that is far beyond my possibilities, nevertheless I stick to the point that the mesure of SORCE it’s probably the best we can actually do measuring TSI, but it’s not precisely measuring it as the mission claims. Therefore as for many other arguments concerneing climate science, science is not settled. On the contrary, the more we dig the more uncertainty gets bigger. I know you will probably answer that in my case a big part of this uncertainty is just lacking of knowledge, but since you proved many times to know a lot more, you will be probably happy to tell us why things are not going as predicted and as settled by this knowledge, will you?
      gg

      • Alessio
        1 dicembre 2012 (12:59)
        Reply

        Guido, I’ve got not problem to accept one’s lack of knowledge in a particular field. Nothing wrong with that (sorry in the first few posts I’ve been quite aggressive and direct. But when I see that similar stuff gets visibility like if it was important, I get angry). There is also nothing wrong if one wants to study and explore the subject matter on his own. But to really understand issues like the SORCE measurements and the processes involved in the radiative transfer and *to be able to make bold claims about pointless research carried on by scientists*, I expect that one went first through fundamental steps like reading (like…a lot) and spending time (like…a lot) in studying books like this http://books.google.co.uk/books/about/An_Introduction_to_Atmospheric_Radiation.html?id=6xUpdPOPLckC&redir_esc=y or this http://books.google.co.uk/books/about/Atmospheric_Radiation_Theoretical_Basis.html?id=Ji0vfj4MMH0C&redir_esc=y or this http://www.amazon.com/Fundamentals-Atmospheric-Radiation-Physics-Textbook/dp/3527405038. Otherwise when I read that claims that “science is all wrong” are supported by statements like “The atmosphere above 645 km emits a lot of visible light.” or “Clouds absorb UVB and *emit visible light* ..” I don’t see the point of even having a conversation. And, this is to answer to duepassi, there is even no point in using fake pointless sweet kindness when one first starts his claims with “mortal blow for climatologists”, “little dirty secret they dont want you to know” etc. Feel free to keep yourself honored to read such wisdom. Tim’s reply to Zavatti’s comment clearly illustrates his way to reply to scientific concerns in his reasoning.

        Another example of Tim’s insightful replies to his post on tallbloke, on the 25th of Nov:

        “I am not sure that we really know if any insolation arrives directly [at the surface]… even “reflected” light has to be absorbed before it is emitted back into space… it could be that everything is absorbed somewhere along the line… the absorbed insolation could then be remitted [without significant loss] or partially transformed or totally transformed… we really know very little… the “cloudy day” spectrum [for example] shows enhanced visible light and reduced UVA… so we have a transformation of energy… we might have “clouds” acting as a prism and “defusing” white light into all the other colours of the rainbow.”

        But anyway, you know what, Guido? I actually have to thank you this time since with this discussion your blog helped reducing the sources of bad science…and of your future controversial posts ;)

        Occhio che se continui di ‘sto passo ti prendono a SkS ;)

        • Guido Guidi
          1 dicembre 2012 (14:04)
          Reply

          In effetti non è proprio il massimo delle mie aspirazioni, ma chissà che questo non possa portare anche quelli bravi a chiudere un’occhio ogni tanto, come del resto succede per quanti hanno correttamente compreso il messaggio. :-)
          gg

          • Maurizio Morabito
            2 dicembre 2012 (00:49)

            I really do not understand what’s Alessio moaning about.

            Tim had several ideas and researched them. He published his thoughts (twice) on the Talkshop and Guido deemed them interesting (or perhaps, intriguing) enough to see them reposted here.

            Is Tim wrong? Who knows. Is he wrong on each and every aspect of his ideas? Who knows. But AFAIK Alessio’s point is not about Tim’s wrongness, rather a general cry against the publication of ideas he (Alessio) finds wrong.

            Now…what is the danger there? Will hordes of Climatemonitor acolytes jump off as one man and start suggesting little children, grandmas and other unsuspecting quasi-skeptics that all solar science is wrong “because a guy called Tim says so”? Will physics faculties get their fundings slashed, astronomers start selling hamburgers, satellites burned deliberately in the atmosphere because of Tim’s (and Guido’s) shaming of a profession and of a science by way of a blog post or two?

            No.

            As Douglas Hofstadter is fond of saying, there is only one way to get the truly good ideas published, and it involves getting a million not-so-good ideas published too. If we started censoring off whoever sounds unorthodox, we would smother solar science (any science!) ourselves in the process.

            These are considerations of pure and basic logic.

            And whatever the true figures behind Tim’s ideas, those ideas are obviously intriguing per-se. These have been my take-home messages wrt them: what if SORCE is not measuring just-and-only TSI? What if atmospheric effects interfere, what if the data is affected by the position in the Earth’s orbit (i.e. by the time of the year)? Have all those effects been taken into account? Is SORCE’s raw data processed accordingly?

            Perhaps the answers are yes some, others no. But whatever the outcome, I for one am grateful to Tim for having been made possible to me and possibly others, to ask those questions: because at the end we will of course be much wiser for them.

        • donato
          1 dicembre 2012 (18:51)
          Reply

          Sono molto contento che, una volta tanto, non vi prendete a male parole! :-) :-)
          Ciao, Donato.

  • Alessio
    29 novembre 2012 (23:15)
    Reply

    Rovati: oddio ho commesso un grosso errore! Eh bem, mi ritirero’ a piangere in un angolino, abbattuto dalla vostra umilta’.

    Ma aspetto con malcelata trepidazione la prossima scoperta di Guido nel molto interessante sottobosco dei climate skeptics.

    • Maurizio Rovati
      30 novembre 2012 (09:36)
      Reply

      Ti prego Alessio (ce l’hai un cognome?), non piangere, mi si spezza il cuore!

  • Tim Cullen
    30 novembre 2012 (11:42)
    Reply

    Alessio,

    The blackbody spectrum provides a theoretical context against which we can compare the solar spectrum. It is a “point of departure” for analysing solar irradiation.

    The blackbody comparison shows that the solar spectrum is not a pure blackbody spectrum. There are apparent absorption losses and emission gains.

    Therefore, this blackbody comparison provides an indication that the solar spectrum might be modified before it arrives at the Earth’s surface. This is just a possibly that we should remember in our further analysis of the solar spectrum.

    The Fraunhofer Lines [rediscovered in 1814] provide the textbook representation of the solar spectrum as it is received on the surface of the Earth. It is a “point of arrival” for analysing solar irradiation.

    Interestingly, Sir David Brewster observed [in 1836] that the intensity of certain Fraunhofer Lines varied with the sun’s elevation and with the seasons.

    The observations of Sir David Brewster imply:
    1. The Earth’s atmosphere modifies the solar spectrum.
    and/or
    2. The Earth’s orbital distance from the Sun modifies the solar spectrum.

    Therefore, Sir David Brewster’s observations provide an indication that the solar spectrum might be modified before it arrives at the Earth’s surface. This is just a possibly that we should remember in our further analysis of the solar spectrum.

    Moving forward to the “satellite age” and the scientific discoveries made since the nineteenth century we find that solar irradiation travels through many particulate layers during its 8 minute journey from it’s “point of departure” [the Sun] and its “point of arrival” [the Earth].

    For example: http://malagabay.files.wordpress.com/2012/11/sorce-transformed-tsi.jpg

    The possibly that solar irradiance is modified “en route” is observationally confirmed by the many “satellite age” discoveries that have been made using spectroscopy [“the study of the interaction between matter and radiated energy” – Wikipedia].

    Overall, the observational evidence indicates:

    a) Science has not conclusively demonstrated that Fraunhofer Lines solely originate in the Sun because solar irradiation is observed to be transformed “en route”.

    b) Science has not conclusively demonstrated that the Sun does not emit radiation as a blackbody because solar irradiation is observed to be transformed “en route”.

    c) Science has not conclusively demonstrated that solar irradiation is not transformed during its journey through the Earth’s atmosphere because solar irradiation is observed to be transformed “en route”.

    Personally, I find it very exciting when I discover that the science is not settled.

    Personally, I find it very regrettable that you find these observations “insulting”.

    However, everyone is entitled to review the evidence and make their own conclusions.

    Kind Regards
    Tim Cullen

    • duepassi
      30 novembre 2012 (14:15)
      Reply

      Tim, I’m personally profoundly sorry for the words Alessio used, which, I think, the very large majority of the people reading this site don’t agree.
      I apologize.
      I’m instead very honoured of reading your opinion.
      You wrote:
      “2. The Earth’s orbital distance from the Sun modifies the solar spectrum.”
      I find this very interesting.
      The eccentricity of the Earth’s orbit is currently about 0.0167, while its maximum is almost 0.058, and its minimum nearly 0.0034; the Earth’s orbit is now nearly circular.
      Wikipedia says:
      “Over the next 10,000 years, northern hemisphere winters will become gradually longer and summers will become shorter. Any cooling effect, however, will be counteracted by the fact that the eccentricity of Earth’s orbit will be almost halved[citation needed], reducing the mean orbital radius and raising temperatures in both hemispheres closer to the mid-interglacial peak.”
      I think this subject should be more deeply examined. I mean correlation between climate and apsidal precession, axial tilt and precession, orbital eccentricity, nutation, and so on. Also I am interested on correlation with the changes of our position with respect to our Galaxy, and the rest of Universe.
      Universe and our galaxy are not omogeneous places, and I think that we can expect influences on our climate.
      Cosmic rays (wherever they come from) have consequences on our climate (clouds, ozone hole…).
      Earth is not a perfect sphere, it is not simply an oblate spheroid, it is not a “pear”, like someone said :-)
      Gauss said it is a geoid, that is a “mathematical figure of the Earth”. This is not exactly true, because Earth is a moving, changing thing very similar to a geoid :-)
      But I wonder what all these changes do as far as distribution of heat is considered. It is not exactly divided by the sword of Solomon :-)
      I suspect that part of the GW is simply due to a problem of distribution, caused by all these movements and changes.
      Not all, may be, but a part of it. imho

      • Tim Cullen
        30 novembre 2012 (17:12)
        Reply

        duepassi 30 novembre 2012

        My personal perspective is that the variations in the Earth’s orbit and axial tilt are very significant parameters that influence climate.

        The majority of long term predictions are based upon the assumption that everything else stays the same. The theory of Uniformitarianism is firmly embedded in many areas of mainstream science:

        Uniformitarianism is the assumption that the same natural laws and processes that operate in the universe now, have always operated in the universe in the past and apply everywhere in the universe. It has included the gradualistic concept that “the present is the key to the past” and is functioning at the same rates.

        http://en.wikipedia.org/wiki/Uniformitarianism

        Unfortunately, the geological record of the Earth indicates there are periods of gradual change that are interrupted by relatively short periods of traumatic [violent] change.

        Therefore, I think we need to keep a very open mind because Wikipedia’s “over the next 10,000 year” predictions are founded upon a false assumption: Uniformitarianism.

        The historical record indicates there have been natural [and significant] changes in the Earth’s climate over the last 2,000 years: Little Ice Age, Medieval Warm Period, Roman Warm Period.

        But I wonder what all these changes do as far as distribution of heat is considered.

        Heat distribution is another extremely important element in climate.

        Contradictorily, the development of extensive ice sheets [as in an “Ice Age”] requires a significant input of heat to drive the evaporation of water. The evaporated water then needs to be transported to a cold region where is precipitated as snow [which then accumulates to form ice sheets].

        Interestingly, the discovery of “fast frozen” mammoths in Siberia [still with food in their mouths] suggests that rapid axial tilt may be associated with the equally rapid onset of an “Ice Age”.

        There is still so much we do not know with any degree of certainty.

        Kind regards
        Tim

        • duepassi
          30 novembre 2012 (21:05)
          Reply

          Thank you. I think that wikipedia is too simplicistic when it says:
          “Any cooling effect, however, will be counteracted …”
          I think that many climatic factors don’t act in only one single way, but have contrasting effects that should be as best carefully calculated as possible. I think of the clouds, for example, that can have negative or positive effects, and cannot be considered a secondary question; but I could mention others, volcanic eruptions, and so on.
          Ok, a certain degree of counteracting effect is certain, but, how much ?
          Sun is considered a constant in computer models, for example, and many other factors are not considered.
          I find curious this behaviour; as Marcello Truzzi put it, “extraordinary claims require extraordinary proof.”
          imho

  • Tim Cullen
    30 novembre 2012 (12:38)
    Reply

    franco zavatti 27 novembre 2012
    Non conta molto nel contesto generale ma non fa una buona impressione la figura dello spettro in giornate serene e nuvolose, presa da un sito commerciale, in cui la griglia orizzontale non coincide con le “tacche” del grafico e in cui si visualizzano densità molto diverse da quelle dell’esosfera/magnetosfera.

    Franco,
    One of the problems [for my perspective] is that the transformation of solar irradiation is largely ignored in the scientific literature [although there are many published satellite “images” that clearly show that the transformation of insolation is a real phenomena].

    Unfortunately, I have only found a few “actual” terrestrial solar spectrums published on the internet. The majority of solar spectrums I encountered were just “indicative” or “generalised”.

    One of the other problems [for my perspective] is trying to quantify the transformations and other energy inputs received by the Earth because the scientific literature predominately concentrates upon the satellites measurement of TSI.

    However, if we search back through the literature there are references to the terrestrial measurement of TSI [before the “satellite age”] ranging from 1,322 to 1,465 W m2.

    Measurement of the absolute value of total solar irradiance (TSI) is difficult from the Earth’s surface because of the need to correct for the influence of the atmosphere. Langley (1884) attempted to minimise the atmospheric effects by taking measurements from high on Mt. Whitney in California, and to estimate the correction for atmospheric effects by taking measurements at several times of day, for example, with the solar radiation having passed through different atmospheric pathlengths. Between 1902 and 1957, Charles Abbot and a number of other scientists around the globe made thousands of measurements of TSI from mountain sites. Values ranged from 1,322 to 1,465 W m–2, which encompasses the current estimate of 1,365 W m–2. Foukal et al. (1977) deduced from Abbot’s daily observations that higher values of TSI were associated with more solar faculae (e.g., Abbot, 1910).

    http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch1s1-4-3.html

    If we compare the maximum “terrestrial” measurement of 1,465 W/m2 with the maximum “satellite age” measurement of 1,412 W/m2 we find a difference of around 50 Wm2.

    The actual direct solar irradiance at the top of the atmosphere fluctuates by about 6.9% during a year (from 1.412 kW/m² in early January to 1.321 kW/m² in early July) due to the Earth’s varying distance from the Sun, and typically by much less than 0.1% from day to day.

    http://en.wikipedia.org/wiki/Solar_constant

    From my perspective a discrepancy of 50 W/m2 is worthy of further investigation.
    From my perspective we still have a lot to discover. I might be wrong.
    Unfortunately, we don’t really know. The science is not settled.

  • Alessio
    3 dicembre 2012 (13:32)
    Reply

    Maurizio, domattina durante la tua quotidiana blog review ti imbatti in un post del signor Pinco Pallino, rimbalzato di qua’ e di la’, dove ti spiegano che, ohibo’ non ce l’hanno raccontata giusta sul galleggiamento delle navi. Questi scienziati accettano roba scritta dai greci (e si sa come va la loro economia…) e tanto tempo fa (tipo..piu’ di venti anni fa eh) e pensano che molecoline d’acqua tutte assieme tengano su una nave che pesa tonnellate. Fuffa. Sai perche’, facile. Se ‘sti scienziatucoli si fossero presi la briga di vedere che ci sta nell’aqcua e sotto la nave, avrebbero visto che c’e’ il sotto del mare. O della tinozza. e il fatto che la nave ti preme sul fondo innesca un rimbalzo molecolare ultrasonico che te, la nave, la vedi che sta su. Il sasso non sta su che’ il rimbalzo molecolare e’, ovviamente, troppo piccolo.

    Se leggi queste perle di saggezza, pensi “ohibio’. Queste sono idee non ortodosse che mi fanno pensare. Spetta che le divulgo ancora un po’. Possono essere giuste o sbagliate, chi lo sa? Diamogli lo spazio che si merita ogni idea bislacca. Continuiamo ad insinuare il mystero.

    Seriamente le robe che scrive Tim sono a quel livello. E basta un minimo di fisica di base per accorgersi delle boiate che ho riportato nell’ultimo mio commento, estratte da una sua risposta sul blog.

    • Maurizio Morabito
      4 dicembre 2012 (00:52)
      Reply

      Padronissimo di pensare come la pensi. Continuo però a non capire perché ti dovrebbe dare fastidio che Guido faccia sul blog di Guido quello che pare e piace a Guido? A meno che tu non sia il suo Angelo Custode?

  • The danger of ideas… | Omnologos
    9 settembre 2013 (22:46)
    Reply

    [...] I really do not understand what’s Alessio moaning about. [...]


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