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1.
M. Golay N. Cramer D. Huguenin B. Nicolet A. Blecha 《Astrophysics and Space Science》1985,109(1):191-212
The present paper is the introduction to a systematic analysis of 123 6-degree fields near the galactic plane, recorded in the medium ultraviolet (2000 Å) by the ballon-borne experiment SCAP 2000 of the Laboratoire d'Astronomie Spatiale, Marseille, and Geneva Observatory. The available data are presented and the general properties of the images are briefly discussed.It is shown that the high selectivity of the UV passband regarding spectral type, together with the strong interstellar extinction at that wavelength, provide the necessary conditions for an efficient application of Wolf's method to study the distribution of interstellar matter in the solar neighbourhood. The results of a fast analysis of the available data are presented here. 相似文献
2.
A general analysis of ionospheric conditions has been made in the light of possible ionic reactions occurring in the upper atmosphere. Data obtained on various parameters, such as ionic production and recombination, show that precise knowledge of the spectral distribution of solar radiation is needed and that other experimental determinations on dissociative recombinations are required.
The ionic complexity of the ionosphere is underlined by describing how the atomic ions O+ and N+ react with N2, O2 and NO molecules. The behavior of the molecular ions N+2, O+2and NO+depends on a group of simultaneous processes involving charge transfers and ionatom interchanges which are more important than dissociative recombinations. The altitude distribution of ions is exemplified by discussing the relative importance of various loss coefficients in the D-, E- and F-regions. It is seen that molecular nitrogen ions are subject to important charge transfer processes, that nitric oxide ions are always final products destroyed only by dissociative recombination. Additionally, the entire production of atomic oxygen ions is related to the photoionization of molecular nitrogen. Some information is also given on possible anomalies in the ratio of O+2 and NO+ densities in the lower ionosphere. From the lack of sufficient experimental information on ionic processes it is shown that a precise analysis of ionospheric behavior remains highly speculative. 相似文献
3.
A general analysis of the absorption of the Schumann-Runge bands of molecular oxygen has been made in order to compare the various experimental and theoretical results which have been obtained for an application to the O2 atmospheric absorption and its photodissociation in the mesosphere and stratosphere. The different values of the oscillator strengths deduced from the laboratory absorption spectra and of the predissociation linewidths used for the calculation of the absorption have been compared.Calculations based on a Voight profile of the O2 rotational lines have led to simple formulas for atmospheric applications taking into account that the total photodissociation rate in the stratosphere depends strongly on the absorption of solar radiation in the spectral range of the O2 Herzberg continuum. Specific examples are given. 相似文献
4.
Marcel Nicolet 《Planetary and Space Science》1981,29(9):951-974
A critical analysis has been made of solar irradiance in the spectral region covering wavelengths from 100 nm upwards; the absorption characteristics of molecules of oxygen and ozone have been taken into account with a view to the direct application of the results to atmospheric photochemistry. The absorption of radiation by these molecules results in the photodissociation of both of them in the homosphere, and it also makes possible the penetration of solar radiation from the thermosphere, through the mesosphere and the stratosphere, down to the troposphere.Special attention has been given to each of the following spectral regions: Lyman-alpha radiation at 121.6 nm, the O2 Schumann-Runge continuum at wavelengths less than 175 nm, the O2 Schumann-Runge band system from 200 to 175 nm, and the O2 Herzberg continuum at 242.4 nm. For absorption by ozone, the solar spectrum has been analysed in the following regions: the Hartley band at wavelengths less than 310 nm, the Huggins bands at wavelengths above 310 nm and the visible Chappuis bands. Finally, for the photodissociation of O3, particular attention has been given to the transition region (300–320 nm) in which there is a change-over from the production of the excited atom O(1D) to that of the atom in its ground state O(3p). 相似文献
5.
M. Nicolet 《Theoretical and Applied Climatology》1951,3(1):209-219
Résumé Le problème de la densité spectrale du flux énergétique du rayonnement solaire extraterrestre a été réexaminé en relation, avec le problème de la constante solaire. En utilisant les densités spectrales de flux énergétique du rayonnement global de la photosphère, on a déterminé la distribution spectrale extraterrestre du rayonnement solaire de 0,2 à 10 . Ces nouvelles données doivent être employées dans les études actinométriques. L'application des résultats indique sous quelles formes les diverses, corrections ultraviolettes et infrarouges pour le rayonnement non observable ont été introduites pour obtenir la valeur de la constante solaire. En outre, l'explication est donnée des résultats actinométriques les plus récents.Enfin, la valeur de la constante solaire doit être égale à 1,98 calories dans l'échelle récente (1932-34-48) de la Smithsonian, Institution. Néanmoins, on retiendra qu'une erreur qui peut dépasser ±5% peut être admise tant que de nouvelles mesures,absolues des densités spectrales ou du flux total extra-terrestre n'ont pas été effectuées.
Summary The problem of the spectral density of the energy flux of the extra-terrestrial solar radiation has been examined anew in relation to the problem of the solar constant. Based on, the spectral densities of the energy flux of the total radiation of the photosphere, the extra-terrestrial spectral distribution of the solar radiation has been determined from 0,2 to 10 . These new values ought, to be employed in actinometric investigations. The use of these results shows in which manner the different ultraviolet and infra-red corrections for the radiation which cannot be observed, have been introduced for determining the solar constant. In addition, an explanation is given of the latest actinometric results.It results that the solar constant ion the new scale of the Smithsonian Institution (1932-1934-1948) must be 1.98 cal cm–2 min–1. Nevertheless, an error which can exceed ±5% must be admitted as long as newabsolute measurements of the spectral densities or of the total extra-terrestrial flux have not been carried out.
Zusammenfassung Das Problem der spektralen Dichte des Energieflusses der extraterrestrischen Sonnenstrahlung wurde im Hinblick auf das Problem der Solarkonstanten neuerdings geprüft. Unter Benützung der spektralen Dichten des Energieflusses der Gesamtstrahlung der Photosphäre wurde die Spektralverteilung der extraterrestrischen Sonnenstrahlung von 0,2 bis 10 bestimmt. Die neuen Werte sollen bei aktinometrischen Untersuchungen Verwendung finden. Aus der Untersuchung läßt sich erkennen, in welcher Form die verschiedenen, der direkten Beobachtung nicht zugänglichen Strahlungskorrektionen für Ultraviolett und Ultrarot zur Bestimmung des Wertes der Solarkonstanten eingeführt wurden; außerdem konnte für die neuesten aktinometrischen Ergebnisse eine Erklärung, gegeben werden.Aus der Untersuchung ergibt sich, daß die Solarkonstante in der neuen Skala der Smithsonian Institution (1932-1934-1948) zu 1,98 cal/cm2min angesetzt werden muß. Immerhin muß mit einer Unsicherheit von mindestens ±5% gerechnet werden, solange nicht neue Absolutbestimmungen der Spektraldichten oder des gesamten extraterrestrischen Energieflusses durchgeführt sind.相似文献
6.
The vertical distribution of the methane concentration in the stratosphere is related to its dissociation by two simultaneous daytime reactions with excited oxygen atoms O(1D) and with OH radicals and depends on the stratospheric eddy diffusion coefficient.Dissociation of CH4 in the lower stratosphere leads to the production of CO molecules while in the upper stratosphere thepphotodissociation of CO2 molecules is an additional process to the CO production.In the upper stratosphere (40±10 km) there is an equilibrium between the formation and destruction processes of carbon monoxide which leads to a minimum of its mixing ratio. There is an increase of the CO mixing ratio in the troposphere and mesosphere compared with that of the stratosphere.The vertical distribution of the CO mixing ratio is closely related to the eddy diffusion coefficient in the whole stratosphere but the absolute values of the hydroxyl radical concentration also determine the values of the CO mixing ratio. 相似文献
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The results of calculations of the multiply-scattered solar-induced radiation field in the troposphere and stratosphere are presented for direct application to photochemical models. The enhancement factors due to multiple scattering are given for the heights, solar zenith angles and wavelengths (between 800 and 300 nm) which play a role in the photodissociation of various atmospheric constituents. 相似文献
9.
A detailed study is made of the atmospheric attenuation of the dissociation of nitric oxide in the mesosphere and stratosphere. The nitric oxide dissociation profile depends on the absorption of the discrete Schumann-Runge bands of O2. The major contribution to the dissociation rate of NO is the predissociation of the δ(0-0) and δ(1-0) bands which can reach the stratosphere. 相似文献
10.
A detailed calculation of the nitric oxide photodissoeiation rate has been made for application to mesospheric and stratospheric photochemistry. It takes into account a new determination of the oscillator strengths of the NO bands and is based on a critical analysis of the solar flux. Moreover it entails a complete determination of the molecular oxygen attenuation allowing for the rotational fine structure including the Voight profile of the Schumann-Runge bands. 相似文献