Good-bye, 'Scattering' Rayleigh!
Unraveling the Greatest Astronomical Mystery
Global, highly intense blue-colored diffuse auroras, rather than Rayleigh scattering, are the main contributor to the blueness of the daytime sky.
The clear, sunward sky is nearly always blue mainly because the ionosphere is self-coloring due to its capability of being a planetary-scale discharge tube wherein global, continuous blue-colored auroras mostly from molecular and atomic nitrogen emissions, especially the emissions of N2+ ions upon being impact-excited, are prevalent almost along the daytime. Simply, the diffuse sky radiation is blue mainly because the bulk of this light is blue diffuse auroras.
From the perspective of the classical polar auroras, or by the comparison with them, we find that:
First, all the agents needed to operate extremely intense auroral activities are continuously present in the whole sunward ionosphere.
Second, all the conditions relevant to the occurrence of extremely bright, blue-colored diffuse auroras could be persistently observed throughout the daytime ionosphere.
Third, all the effects associated with the events of exceptionally bright auroras always appear in the daytime sky. Accordingly, relatively and comparatively speaking, very bright, veiling blue-colored auroras should be continuously present in an almost uniformly diffuse state in the whole sunward ionosphere.
Concise Explanation and Interpretation
It is known that excited oxygen atoms are responsible for the emission of the two most principal and most typical auroral lines: the green wavelength 557.7nm and red wavelength 630.0nm.
However, both of these two emissions belong to the forbidden transitions (meta-stable states): 557.7nm [OI] line(1S→1D) and 630.0nm [OI] line(1D→3P). Therefore, unless the green-excited oxygen atom passes its radiative lifetime whose duration is 0.75sec without suffering any collision, it will not emit the green photon (557.7nm). Otherwise, the gained energy which caused the activation will be yielded to the other colliding particle in a non-radiative de-excitation. Also, unless the red-excited oxygen atom passes its radiative lifetime whose duration is 110 seconds without suffering any collision, it will not emit the red photon (630.0nm). Otherwise, however, this red-activated oxygen atom will be quenched i.e., the excitation energy will be released to the collision partner in a non-radiative decay. Well, the blue emissions of the excited nitrogen particles belong to the permitted transitions. This means that such excited nitrogen particles can return back to their stable, ground states immediately i.e., in a time of the order of 10-8 sec or even less.
So, whatever high be the density of the ionosphere, the nitrogen particles are able to release their specific visible auroral emissions as soon as these particles are excited.Geophysicists show that the blue emissions of N2* molecules, N2*+ ions, and N*+ ions generally compete with the visible auroral emissions of excited oxygen atoms in giving the aurora its predominant color.
Any way, respecting the blue-hued emissions of the N2*+ ions, we find that 391.4 nm and 427.8 nm lines are the dominant ones. The nitrogen molecules in the sunward ionosphere are ionized to N2+ ions by the action of the so-called solar ultraviolet photons. About 20-35% of the molecular nitrogen at the altitude of E-layer is found as N2+ ions. Afterwards the N2+ ions become excited by the collisions with energized electrons whether precipitating from the magnetosphere or produced as photoelectrons in the process of photo-ionization. Thenceforth, the excited N2*+ ions give blue-hued emissions at 391.4 nm and 427.8 nm wavelengths. Moreover, these blue-hued emissions become well enhanced by the resonance scattering i.e. by absorption and re-emission of these wavelengths from the so-called solar rays, irrespective of the original source of such rays. Thus, the blue photons absorbed by N2+ ions are quickly re-emitted in all directions. Although these processes are concentrated in the E-layer, however, their occurrence encompasses the whole ionosphere. Well, during the daytime, throughout the sunward ionosphere, the different blue-hued nitrogen emissions have the chance to dominate the green and red emissions of the excited oxygen atoms. The latter emissions become greatly suppressed owing to the highly increased probabilities of suffering excitement-aborting collisions. In other words, with respect to the green-excited and red-excited oxygen atoms, the excitement-aborting collisions become relatively so highly probable in the sunward ionosphere because its density increases greatly. Comparatively, this so high increase in the density of the daytime ionosphere happens mainly as a result of the intense photo-dissociation and photo-ionization. No escape, the significant degree of the suppression of the green-excited and red-excited oxygen atoms gives the blue emissions of the excited nitrogen particles, especially N2*+ions, the opportunity to impose their color on the sunward ionosphere. According to, first, the fact that the two main aurora-characterizing emissions belong to the forbidden transitions of the excited oxygen atoms, second, the fact that the geophysicists used to optically deal with the so-described typical features of the auroras of the classical auroral zone in order to judge whether there are any auroral activities or not and, third, the fact that the most important typical feature is the appearance of visible green curtain-like arcs or bands, consequently, the apparent absence of such discrete green arcs from the sunward ionosphere either from the perspective of the ground-stationed observers or of orbit-based observers, led the geophysicists to wrongly think that the sunward ionosphere does not house any bright auroras. Inevitably, all the typical features of the classical auroras are present throughout the daytime sky, but they are embedded in the uniformly diffused, full-sky blue-colored auroras whose intensity is relatively so high to the degree of being able to outshine and conceal almost completely all the features of the classical typical auroras, especially due to the significant suppression of the two main aurora-characterizing emissions of the excited oxygen atoms. This suppression is caused by the highly increased rate of collisions. So far, it now is worthwhile remembering that the ozone molecules whether present in the stratosphere or in the ionosphere can contribute sensibly to the blueness of the sky. The ozone gas is naturally blue. Doubtlessly, Cerenkov radiation occurring in the ionosphere can also sensibly contribute to the blueness of the sky. In addition to, we find many other different ionospheric and stratospheric gases which have their minor contributions to the blueness of the sky.
The most spread, most diffused, or most distributed light in the daytime sky is the blue light. This is not because the blue-hued wavelengths of the so-called solar rays are the most scattered ones, but instead, because, firstly, the bulk of the diffuse blue light of the sky is generated in the sunward ionosphere by the same mechanisms that are responsible for the production of the light of classical polar auroras and, secondly, the overwhelmingly greatest ratio of the colored constituents of the naturally clean atmosphere is blue-colored.
Certainly speaking, the contribution of Rayleigh scattering to the blueness of the sky could be described as insignificant or even optically negligible. In other words, the explanation of the blueness of the daytime sky in terms of Rayleigh scattering is not acceptable at all, though the very Rayleigh's law of scattering isn't wrong. So, the daytime sky is bright and blue mainly due to the fact that the sunward ionosphere is self-coloring by the generation of blue auroras, and not at all because the air scatters the short wavelengths of light more than longer wavelengths according to Rayliegh's 1/λ4 law i.e. scattering of light by small molecules in the atmosphere is inversely proportional to the forth power of the wavelength. Expressed another way, the intensity of the scattered light (Is) is related to the intensity of the incident light (I0) by the inverse fourth power of the wavelength: Is/Io = constant λ-4 However, another type of scattering contributes to the blueness of the sky, particularly, in the ionosphere. That is the so-called resonance scattering. Really, on viewing the clear daytime sky the line of sight passes through the illuminated atmosphere which is formed from a transparent colorless troposphere which is about 99% of two colorless gases: nitrogen and oxygen, a transparent pale blue-colored stratosphere, a transparent pale blue-colored lower mesosphere, a transparent blue-colored upper mesosphere, and a brilliantly deep blue-colored ionosphere whose background is the black exosphere.
Briefly, the blueness of the sky and its brightness are mainly due to the presence of blue light-emitting layers overlying the colorless troposphere. Precisely, this is the main genuine reason behind the blueness of the clear daytime sky. However, all the limb view images of the atmosphere photographed from different terrestrial orbits, e.g. from space shuttles, show this fact so clearly.
http://www.visualphotos.com/image/1x...ace_over_earth [IMG]file:///C:/DOCUME%7E1/XPPRESP3/LOCALS%7E1/Temp/msohtml1/01/clip_image007.jpg[/IMG] http://www.jpaerospace.com/whatsnewp...cexplorer6.bmp [IMG]file:///C:/DOCUME%7E1/XPPRESP3/LOCALS%7E1/Temp/msohtml1/01/clip_image009.jpg[/IMG] http://www.bom.gov.au/info/climate/c...y/images/3.jpg [IMG]file:///C:/DOCUME%7E1/XPPRESP3/LOCALS%7E1/Temp/msohtml1/01/clip_image011.jpg[/IMG]
http://i.dailymail.co.uk/i/pix/2008/...69_468x286.jpg [IMG]file:///C:/DOCUME%7E1/XPPRESP3/LOCALS%7E1/Temp/msohtml1/01/clip_image012.gif[/IMG] Introduction to the Atmosphere: Background Material
Is Colonel Wheels saying: 'Goodbye, Lord Rayleigh! Please don't forget to 'scatter' my blue and red salutes to all the Earth's peoples, but according to your law'?