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Solar eclipse
About: Solar eclipse is a research topic. Over the lifetime, 2737 publications have been published within this topic receiving 22625 citations.
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TL;DR: In this paper, the authors compare the extent of flash spectrum crescents from emission lines formed in the chromosphere-corona transition zone with two simple but fundamentally different models describing this region.
Abstract: An Aerobee 170 rocket carried five slitless extreme ultraviolet (XUV) spectroheliographs into the March 7, 1970, solar eclipse. Salt water damage left latent images on 16 exposures of the XUV camera covering the wavelength range from 1390 A to 1945 A. The salt water damage made the absolute calibration of the spectroheliograms uncertain. Therefore, the analysis in this paper is based on a comparison of the extent of flash spectrum crescents from emission lines formed in the chromosphere-corona transition zone with two simple but fundamentally different models describing this region. The observations can be satisfactorily described by an inhomogeneous model where cool spicules are surrounded by a transition zone which has the same temperature and density structure as the chromospheric coronal transition zone customarily used in spherically symmetric models of the quiet Sun.
12 citations
01 Jun 1972
TL;DR: In this paper, the authors investigated whether the observed variations in electric parameters are caused by near-ground processes (related to eddy diffusion) or by high-altitude processes and concluded that simple models are not sufficient to explain the sequence of variations seen in the data.
Abstract: Measurements of the electric field, the vertical current density, space charge and conductivity have been carried out at five ground stations and three series of free-air measurements during the 7 March 1970 solar eclipse in and near the totality zone. The problem whether the observed variations in electric parameters are caused by near-ground processes (related to eddy diffusion) or by highaltitude processes is not yet solved. It was possible, however, to offer a speculative explanation with the first assumption for the majority of the observations. The most important conclusion is the ecquisition of a better understanding of the requirements for measurements made for investigating solar eclipse effects. Also, it seems that simple models are not sufficient to explain the sequence of variations seen in the data.
12 citations
TL;DR: In this paper, a total eclipse of the Sun was visible on the Greek island Kastelorizo (36.150°N, 29.596°E) and seven spectroradiometers were installed in order to measure the variability of different components of the radiation field during the eclipse.
Abstract: On 29 March 2006, a total eclipse of the Sun was visible on the Greek island Kastelorizo (36.150°N, 29.596°E). An extended set of instruments was installed in order to measure the variability of different components of the radiation field during the eclipse. Seven spectroradiometers (two scanning double monochromators measuring especially in the UV range, 4 photo diode array instruments and one CCD-spectrograph for the UV and visible wavelength range) performed measurements during 28 and 29 March. A narrow band multi-filter radiometer and two broadband erythemal and UVA radiometers were operated with about 1 sec temporal resolution. Two sun-photometers were used to measure ozone column and aerosol optical depth. The weather conditions on March 28 were almost perfect, whereas on 29 March thin cirrus clouds were occasionally present in front of the sun. Details about the observed changes in the radiation field on the eclipse day are presented and compared with model calculations of the change in extraterrestrial solar irradiance. The results show an underestimation of the model calculations compared with measurements, with respect to the effect of the limb darkening on the spectral behavior of the solar irradiance during the eclipse. The absolute changes in the global and direct irradiance and their wavelength dependencies are discussed. Finally, the decrease in total ozone retrieved during the course of the eclipse from direct irradiance measurements is investigated with respect to the effect of the limb darkening and the influence of the diffuse radiation entering the field of view of the Brewer spectroradiometer.
12 citations
TL;DR: In this paper, the authors used the 1D NLTE radiative transfer COde for Solar Irradiance (COSI) to model the measured light curves and corresponding center-to-limb variations of the solar brightness.
Abstract: We analyze the light curves of the recent solar eclipses measured by the Herzberg channel (200 – 220 nm) of the Large Yield RAdiometer (LYRA) onboard Project for OnBoard Autonomy (PROBA2). The measurements allow us to accurately retrieve the center-to-limb variations (CLV) of the solar brightness. The formation height of the radiation depends on the observing angle, so the examination of the CLV provide information about a broad range of heights in the solar atmosphere. We employ the 1D NLTE radiative transfer COde for Solar Irradiance (COSI) to model the measured light curves and corresponding CLV dependencies. The modeling is used to test and constrain the existing 1D models of the solar atmosphere, e.g. the temperature structure of the photosphere and the treatment of the pseudo-continuum opacities in the Herzberg continuum range. We show that COSI can accurately reproduce not only the irradiance from the entire solar disk, but also the measured CLV. Hence it can be used as a reliable tool for modeling the variability of the spectral solar irradiance.
12 citations
TL;DR: In this paper, the authors studied the effect of the annular solar eclipse on water vapor concentration in the surface layer during 8-18 January 2010 at a land station located close to the central line of the eclipse.
12 citations