Showing papers on "Solar eclipse published in 2008"
TL;DR: In this article, a comparison of vertical incidence sounding (VS) and vertical total electron content (TEC) data from above-selected ionosonde stations in Europe has been made to study the ionospheric/thermospheric response to solar radiation changes.
123 citations
TL;DR: In this paper, the authors investigated the combined point spread function (PSF) of the BFI and the SOT onboard the Hinode spacecraft for the blue, green, and red continuum channels.
Abstract: Aims. We investigate the combined point spread function (PSF) of the Broadband Filter Imager (BFI) and the Solar Optical Telescope (SOT) onboard the Hinode spacecraft. Methods. Observations of the Mercury transit from November 2006 and the solar eclipse(s) from 2007 are used to determine the PSFs of SOT for the blue, green, and red continuum channels of the BFI. For each channel, we calculate large grids of theoretical point spread functions by convolution of the ideal diffraction-limited PSF and Voigt profiles. These PSFs are applied to artificial images of an eclipse and a Mercury transit. The comparison of the resulting artificial intensity profiles across the terminator and the corresponding observed profiles yields a quality measure for each case. The optimum PSF for each observed image is indicated by the best fit. Results. The observed images of the Mercury transit and the eclipses exhibit a clear proportional relation between the residual intensity and the overall light level in the telescope. In addition, there is an anisotropic stray-light contribution. These two factors make it very difficult to pin down a single unique PSF that can account for all observational conditions. Nevertheless, the range of possible PSF models can be limited by using additional constraints like the pre-flight measurements of the Strehl ratio. Conclusions. The BFI/SOT operate close to the diffraction limit and have only a rather small stray-light contribution. The FWHM of the PSF is broadened by only ~1% with respect to the diffraction-limited case, while the overall Strehl ratio is ~0.8. In view of the large variations – best seen in the residual intensities of eclipse images – and the dependence on the overall light level and position in the FOV, a range of PSFs should be considered instead of a single PSF per wavelength. The individual PSFs of that range allow then the determination of error margins for the quantity under investigation. Nevertheless, the stray-light contributions are found to be best matched with Voigt functions with the parameters σ = 0 008 and γ = 0 004, 0 005, and 0 006 for the blue, green, and red continuum channels, respectively.
97 citations
TL;DR: The effects of the total solar eclipse on meteorological parameters, though very clear, were shown to be controlled by local factors rather than the eclipse mag- nitudes, and the turbulence activity near surface was sup- pressed causing a decrease in the Planetary Boundary Layer as mentioned in this paper.
Abstract: This paper provides the overview of an inte- grated, multi-disciplinary effort to study the effects of the 29 March 2006 total solar eclipse on the environment, with special focus on the atmosphere. The eclipse has been visible over the Eastern Mediterranean, and on this occasion several research and academic institutes organised co-ordinated ex- perimental campaigns, at different distances from eclipse to- tality and at various environments in terms of air quality. De- tailed results and findings are presented in a number of com- ponent scientific papers included in a Special Issue of Atmo- spheric Chemistry and Physics. The effects of the eclipse on meteorological parameters, though very clear, were shown to be controlled by local factors rather than the eclipse mag- nitudes, and the turbulence activity near surface was sup- pressed causing a decrease in the Planetary Boundary Layer. In addition to the above, the decrease in solar radiation has caused change to the photochemistry of the atmosphere, with night time chemistry dominating. The abrupt "switch off" of the sun, induced changes also in the ionosphere (140 up to 220 km) and the stratosphere. In the ionosphere, both photochemistry and dynamics resulted to changes in the re- flection heights and the electron concentrations. Among the most important scientific findings from the experiments un- dertaken has been the experimental proof of eclipse induced thermal fluctuations in the ozone layer (Gravity Waves), due to the supersonic movement of the moon's shadow, for the first time with simultaneous measurements at three altitudes namely the troposphere, the stratosphere and the ionosphere.
91 citations
TL;DR: In this paper, a revised eclipse factor, FR, is constructed to describe the vari- ations of solar radiation during the solar eclipse, and the effect of this eclipse on the ionosphere with a mid- and low-latitude ionosphere theoretical model by using the revised eclipse factors during this eclipse.
Abstract: A total eclipse occurred on 11 August 1999 with its path of totality passing over central Europe in the lat- itude range 40 -50 N. The ionospheric responses to this eclipse were measured by a wide ionosonde network. On the basis of the measurements of foE, foF1, and foF2 at six- teen ionosonde stations in Europe, we statistically analyze the variations of these parameters with a function of eclipse magnitude. To model the eclipse effects more accurately, a revised eclipse factor, FR, is constructed to describe the vari- ations of solar radiation during the solar eclipse. Then we simulate the effect of this eclipse on the ionosphere with a mid- and low-latitude ionosphere theoretical model by using the revised eclipse factor during this eclipse. Simulations are highly consistent with the observations for the response in the E-region and F1-region. Both of them show that the max- imum response of the mid-latitude ionosphere to the eclipse is found in the F1-region. Except the obvious ionospheric response at low altitudes below 500 km, calculations show that there is also a small response at high altitudes up to about 2000 km. In addition, calculations show that when the eclipse takes place in the Northern Hemisphere, a small ionospheric disturbance also appeared in the conjugate hemi- sphere.
88 citations
TL;DR: In this article, the variations in the surface ozone concentration, the solar ultraviolet radiation and the meteorological parameters at the ground before, during and after the total solar eclipse of 29 March 2006 have been examined.
Abstract: In this study the variations in the surface ozone concentration, the solar ultraviolet radiation and the meteorological parameters at the ground before, during and after the total solar eclipse of 29 March 2006 have been examined. This analysis is based on the measurements performed at four stations located in the greater Athens basin in Greece. The experimental data demonstrated that the solar eclipse phenomenon affects the surface ozone concentration as well as the temperature, the relative humidity and the wind speed near the ground. The decrease in the surface ozone concentration that observed after the beginning of the eclipse event lasted almost two hours, probably due to the decreased efficiency of the photochemical ozone formation. The reduction of the solar ultraviolet radiation at 312 and 365 nm reached 97% and 93% respectively, while the air temperature dropped, the relative humidity increased and the wind speed decreased.
81 citations
TL;DR: In this paper, the combined PSF of the BFI and the SOT onboard the Hinode spacecraft was investigated for the blue, green, and red continuum channels of BFI, and the resulting artificial intensity profiles across the terminator and the corresponding observed profiles yielded a quality measure for each case.
Abstract: The combined PSF of the BFI and the SOT onboard the Hinode spacecraft is investigated. Observations of the Mercury transit from November 2006 and the solar eclipse(s) from 2007 are used to determine the PSFs of SOT for the blue, green, and red continuum channels of the BFI. For each channel large grids of theoretical point spread functions are calculated by convolution of the ideal diffraction-limited PSF and Voigt profiles. These PSFs are applied to artificial images of an eclipse and a Mercury transit. The comparison of the resulting artificial intensity profiles across the terminator and the corresponding observed profiles yields a quality measure for each case. The optimum PSF for each observed image is indicated by the best fit. The observed images of the Mercury transit and the eclipses exhibit a clear proportional relation between the residual intensity and the overall light level in the telescope. In addition there is a anisotropic stray-light contribution. ... BFI/SOT operate close to the diffraction limit and have only a rather small stray-light contribution. The FWHM of the PSF is broadened by only ~1% with respect to the diffraction-limited case, while the overall Strehl ratio is ~ 0.8. In view of the large variations -- best seen in the residual intensities of eclipse images -- and the dependence on the overall light level and position in the FOV, a range of PSFs should be considered instead of a single PSF per wavelength. The individual PSFs of that range allow then the determination of error margins for the quantity under investigation. Nevertheless the stray-light contributions are here found to be best matched with Voigt functions with the parameters sigma = 0."008 and gamma = 0."004, 0."005, and 0."006 for the blue, green, and red continuum channels, respectively.
65 citations
TL;DR: In this paper, the effects of the partial (about 77%) solar eclipse (SE) in the ionospheric plasma were observed using the Kharkov incoherent scatter radar.
Abstract: The observations of the effects of the partial (about 77%) solar eclipse (SE) of March 29, 2006, in the ionospheric plasma are presented. The experimental data were obtained using the Kharkov incoherent scatter radar. At the moment of the maximum phase of SE, a decrease in the critical frequency of the ionospheric F2 layer by 18%, a depletion of the density in the F2 layer maximum by 33%, and an increase in the maximum height zm by 30 km were observed. The solar eclipse caused a decrease in the electron and ion temperatures by 150–300 and 100–200 K, respectively, within the height range 210–490 km. An increase in the relative density of the hydrogen ions during the maximum phase of SE by 20–25% within the height range 900–1200 km is detected. Calculations of the parameters of dynamical processes and thermal regime of the ionospheric plasma during SE are performed.
34 citations
TL;DR: GPS observations from EUREF permanent GPS network were used to observe the response of TEC (Total Electron Content) to the total solar eclipse on October 3, 2005, under quiet geomagnetic conditions of the daytime ionosphere as mentioned in this paper.
33 citations
TL;DR: In this article, the effects of the total solar eclipse on field crops and marine zooplankton were investigated in a field crop and marine zooplankton assemblage, and various vertical migratory behaviors were adopted by different species.
Abstract: Some effects in the biosphere from the Total Solar Eclipse of 29 March 2006 were investigated in field crops and marine zooplankton. Taking into account the decisive role of light on plant life and productivity, measurements of photosynthesis and stomatal behaviour were conducted on seven important field-grown cereal and leguminous crops. A drop in photosynthetic rates, by more than a factor of 5 in some cases, was observed, and the minimum values of photosynthetic rates ranged between 3.13 and 10.13 μmol CO 2 m −2 s −1 . The drop in solar irradiance and the increase in mesophyll CO 2 -concentration during the eclipse did not induce stomatal closure thus not blocking CO 2 uptake by plants. Light effects on the photochemical phase of photosynthesis may be responsible for the observed depression in photosynthetic rates. Field studies addressing the migratory responses of marine zooplankton (micro-zooplankton (ciliates), and meso-zooplankton) due to the rapid changes in underwater light intensity were also performed. The light intensity attenuation was simulated with the use of accurate underwater radiative transfer modeling techniques. Ciliates, responded to the rapid decrease in light intensity during the eclipse adopting night-time behaviour. From the meso-zooplankton assemblage, various vertical migratory behaviours were adopted by different species.
27 citations
TL;DR: In this paper, the response of the equatorial electrojets to solar eclipses is studied and it is shown that the depression of the EEJ during an eclipse favors the formation of a counter electrojet.
26 citations
TL;DR: Other astronomical references in the Epic are analyzed, without assuming the existence of an eclipse, and it is speculated that these references, plus the disputed eclipse reference, may refer to that specific eclipse.
Abstract: Plutarch and Heraclitus believed a certain passage in the 20th book of the Odyssey (“Theoclymenus's prophecy”) to be a poetic description of a total solar eclipse. In the late 1920s, Schoch and Neugebauer computed that the solar eclipse of 16 April 1178 B.C.E. was total over the Ionian Islands and was the only suitable eclipse in more than a century to agree with classical estimates of the decade-earlier sack of Troy around 1192–1184 B.C.E. However, much skepticism remains about whether the verses refer to this, or any, eclipse. To contribute to the issue independently of the disputed eclipse reference, we analyze other astronomical references in the Epic, without assuming the existence of an eclipse, and search for dates matching the astronomical phenomena we believe they describe. We use three overt astronomical references in the epic: to Bootes and the Pleiades, Venus, and the New Moon; we supplement them with a conjectural identification of Hermes's trip to Ogygia as relating to the motion of planet Mercury. Performing an exhaustive search of all possible dates in the span 1250–1115 B.C., we looked to match these phenomena in the order and manner that the text describes. In that period, a single date closely matches our references: 16 April 1178 B.C.E. We speculate that these references, plus the disputed eclipse reference, may refer to that specific eclipse.
TL;DR: The observations here on the temporal variation of the celestial patterns of the degree p and angle alpha of linear polarization of the eclipsed sky measured in the red (650 nm), green (550 nm), and blue (450 nm) parts of the spectrum shows that the observed polarization phenomena may be general.
Abstract: Using 180 degrees field-of-view (full-sky) imaging polarimetry, we measured the spatiotemporal change of the polarization of skylight during the total solar eclipse on 29 March 2006 in Turkey. We present our observations here on the temporal variation of the celestial patterns of the degree p and angle alpha of linear polarization of the eclipsed sky measured in the red (650 nm), green (550 nm), and blue (450 nm) parts of the spectrum. We also report on the temporal and spectral change of the positions of neutral (unpolarized, p = 0) points, and points with local minima or maxima of p of the eclipsed sky. Our results are compared with the observations performed by the same polarimetric technique during the total solar eclipse on 11 August 1999 in Hungary. Practically the same characteristics of celestial polarization were encountered during both eclipses. This shows that the observed polarization phenomena of the eclipsed sky may be general.
01 Mar 2008
TL;DR: A second partial eclipse occurred on 22 October 1949, and the Division again mounted a major expedition, this time with very different results as mentioned in this paper, which helped establish Australia's reputation as a leader in solar radio astronomy.
Abstract: On 1 November 1948 the Radio Astronomy Group within the Commonwealth Scientific and Industrial
Research Organisation’s Division of Radiophysics observed a partial solar eclipse on a range of radio frequencies at
three different sites within Australia. These observations helped establish Australia’s reputation as a leader in solar
radio astronomy. A second partial eclipse occurred on 22 October 1949, and the Division again mounted a major
expedition, this time with very different results.
This paper examines the contribution of the eclipse observations and contrasts the very different results achieved. While scientific progress is generally well documented, stumbling in the path of progress is often overlooked. In looking to future research it is important to realise that progress is often only made in the face of adversity.
TL;DR: In this paper, the influence of a solar eclipse on solar-radiation fluxes, meteorological parameters, turbulence characteristics, and vertical temperature profiles in the atmospheric boundary layer is analyzed.
Abstract: The influence of a solar eclipse on solar-radiation fluxes, meteorological parameters, turbulence characteristics, and vertical temperature profiles in the atmospheric boundary layer is analyzed. Air-temperature variations caused by an eclipse and time delays of these variations with respect to the onset of the total-eclipse phase in the atmospheric surface and boundary layers are determined. The influence of a solar eclipse on the turbulent kinetic energy, turbulent heat flux, and variance and spectral density of the power of air-temperature pulsations are estimated. Variations in aerosol parameters and concentrations of light ions during a total solar eclipse are discussed.
TL;DR: In this paper, the effects of the solar eclipse on the signals of ULF radio stations, in the intensity of regular radio noise at frequencies of 0.3-10 kHz, and in the number of atmospherics received in Yakutsk mostly from the west have been considered.
Abstract: The effects of the solar eclipse of March 29, 2006, in the signals of ULF radio stations, in the intensity of regular radio noise at frequencies of 0.3–10 kHz, and in the number of atmospherics received in Yakutsk mostly from the west have been considered. The observations were performed using a multichannel parallel analyzer-recorder (11 channels in the frequency band 0.47–8.7 kHz), one-point lightning direction and range finder (0.3–100 kHz), narrow-sector radio noise direction-finder (0.3–10 kHz), recorder of signals from VLF radio stations, and broadband radio noise recorder (0.3–100 kHz). A GPS clock was used to synchronize a recorder of signals from VLF radio stations. The effect was observed in radio signals, radio noise, and number of atmospherics from the direction 270° ± 20° counted off clockwise from the north during the last stage of the eclipse (∼ 1100–1200 UT), when the lunar shadow approached the line of the nighttime terminator and obscured part of the signal propagation path. The effect was observed as an enhancement of the received signals by a factor of ∼1.2, a factor of ∼1.4 increase in the number of atmospherics, and a change in the radio station phase values.
TL;DR: In this article, the authors have shown that the axis of symmetry of the "helmet" type streamers is tilted towards the solar equator and deviations from a radial direction in the western hemisphere are greater than those in the eastern one (21°/8°).
Journal Article•
TL;DR: The Schaeberle camera as discussed by the authors was a hallmark of the Lick Observatory's direct solar eclipse photography program for the first couple decades of the 20th century, and it was used to obtain high resolution images of inner coronal structure and images in which coronal brightness could be studied.
Abstract: The primary goal of the Lick Observatory's direct solar eclipse photography program was to secure high- resolution images of inner coronal structure and images in which coronal brightness could be studied. Between 1889 and 1932 the Observatory sent out seventeen eclipse expeditions worldwide. During these expeditions, direct coronal photography was a significant part of the program for the first couple of decades. By the end of the expedition series, spectrographic observations became of primary importance, yet direct coronal imaging continued. Lick Observatory astronomer, John M. Schaeberle, conceived and constructed a large portable camera of 5-inch aperture with a focal length of 40-feet, and from 1893 the so-called 'Schaeberle Camera' became a hallmark of the Observatory's eclipse expeditions. In this paper we provide details of the Schaeberle Camera's design, setup and operation, and we briefly discuss some of the ways in which Lick Observatory staff and other astronomers used the plates obtained during the various eclipse expeditions in their investigations of the solar corona.
TL;DR: The results of observations of the solar eclipse ionospheric effects on March 29, 2006, are presented in this paper, where it has been established that the eclipse in the E and F1 regions of the polar ionosphere causes a change in the electron density by 15-20%.
Abstract: The results of observations of the solar eclipse ionospheric effects on March 29, 2006, are presented. The observations were conducted using the partial reflection method near Nizhni Novgorod and the vertical sounding method at the automatic ionospheric station near Murmansk. It has been obtained that the electron density at altitudes of 77 and 91 km decreases by a factor of more than 4; in this case the response of the ionosphere at an altitude of 91 km lags behind the eclipse maximum phase on the Earth by approximately 20 min. It has been established that the eclipse in the E and F1 regions of the polar ionosphere causes a change in the electron density by 15–20%. The delay time of this effect varies from 12 to 24 min depending on the altitude. It has been registered that the reflection virtual altitude at altitudes of the ionospheric F region increases in Murmansk and Nizhni Novgorod.
TL;DR: In this article, the results of microwave observations of the ozone content variability in the upper stratosphere and lower mesosphere during a total solar eclipse of March 29, 2006 at the Kislovodsk high-altitude scientific station were presented.
Abstract: We present the results of microwave observations of the ozone content variability in the upper stratosphere and lower mesosphere during a total solar eclipse of March 29, 2006 at the Kislovodsk high-altitude scientific station. An increase in the concentration of mesospheric ozone was recorded during the eclipse. At a height of 60 km, the ozone concentration increased by 40%, which is close to the value of diurnal ozone variations.
TL;DR: In this paper, the authors examined ion composition, ion temperature, and neutral temperature data from the Atmosphere Explorer E spacecraft for the total solar eclipse of 16 February 1980, allowing for examination of eclipse effects to be made over a wide longitude and local time range.
Abstract: [1] Solar eclipses are known to locally disrupt the transport, production, and loss mechanisms in the ionosphere. Ion composition, ion temperature, and neutral temperature data from the Atmosphere Explorer E spacecraft are examined for the total solar eclipse of 16 February 1980. The spacecraft transited twice across the dayside face of the Earth during the course of the eclipse, allowing for examination of eclipse effects to be made over a wide longitude and local time range and for examination of posteclipse recovery of the ionosphere. One orbit from 14 February, occurring over a longitude and local time range similar to that of the first eclipse orbit, is used as control data. The eclipse had a significant effect on the concentrations of both O+ and N+, which both dropped. The concentration of H+ seems to show an eclipse effect, but the concentrations are too low to draw definite conclusions. Signatures of charge exchange between H+ and neutral oxygen are seen in the data from the second eclipse orbit. The ion temperature drops by as much as 60 K. The neutral atmosphere shows no change in temperature during the course of the eclipse. The second eclipse orbit occurred closer to the path of the eclipse than did the first orbit, and the perturbations caused by the eclipse are greater in the second orbit. The control and second eclipse orbit data are compared to results from the International Reference Ionosphere 2000 model. The model results show good qualitative agreement with the ion concentration data.
TL;DR: A decrease in the tectonic aerosol flux during a total solar eclipse was detected for the first time using a backscattering lidar as mentioned in this paper, which was performed in the tunnel of the Baksan Neutrino Observatory, Russian Academy of Sciences, on March 29, 2006.
Abstract: A decrease in the tectonic aerosol flux during a total solar eclipse was detected for the first time using a backscattering lidar. The experiment was performed in the tunnel of the Baksan Neutrino Observatory, Russian Academy of Sciences, on March 29, 2006 (11:17:30 UT). It was found that the decrease in the aerosol release is 2 h ahead of the decrease in the amplitude of seismic vibrations. The decrease in seismic activity is interpreted as a result of lithosphere bulging at the ridge of the eclipse-induced tidal wave, which arrives at the point of observation with a delay. The increased sensitivity of aerosol release to lithosphere deformation in comparison with a seismograph and the detected advance give grounds to consider the change in the lidar signal as a precursor of the change in seismic activity.
TL;DR: Analyses of lunar halo observations during twilight indicate that bright halo displays may also persist during totality, and it is found that diffraction coronas around the totally eclipsed Sun may nevertheless occur.
Abstract: The visibility of stars, planets, diffraction coronas, halos, and rainbows during the partial and total phases of a solar eclipse is studied. The limiting magnitude during various stages of the partial phase is presented. The sky radiance during totality with respect to noneclipse conditions is revisited and found to be typically 1/4000. The corresponding limiting magnitude is +3.5. At totality, the signal-to-background ratio of diffraction coronas, halos, and rainbows has dropped by a factor of 250. It is found that diffraction coronas around the totally eclipsed Sun may nevertheless occur. Analyses of lunar halo observations during twilight indicate that bright halo displays may also persist during totality. Rainbows during totality seem impossible.
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TL;DR: In this article, a part whose retardance is specified at a center wavelength and its stability is stable over temperature changes is determined. But it is not strictly possible to design the part to be achromatic and athermal, and two thicknesses cannot accommodate the three constraints of retardance, retardance slope, and temperature insensitivity.
Abstract: Determining t1 and t2, we have a part whose retardance is specified at a center wavelength, and whose retardance is stable over temperature changes (see figure 4). Note that it is not strictly possible to design the part to be achromatic and athermal. Two thicknesses—that is, two degrees of freedom—can not accommodate the three constraints of retardance, retardance slope, and temperature insensitivity; however, a little give and take with the specifications can lead to acceptable performance in all three.
30 Jan 2008
TL;DR: In this paper, the authors examined the dynamics and spectral distribution of the solar radiation reaching the Earth's surface during the total solar eclipse on March 29, 2006, using a multichannel spectrometer OCEAN USB2000.
TL;DR: The results of single-type optical observations, analysis, and comparison of dynamic characteristics of the effects in the surface atmosphere that accompanied four partial solar eclipses (August 11, 1999, May 31, 2003, October 3, 2005, March 29, 2006) near the city of Kharkiv (Ukraine) are presented in this article.
Abstract: The results of single-type optical observations, analysis, and comparison of dynamic characteristics of the effects in the surface atmosphere that accompanied four partial solar eclipses (August 11, 1999; May 31, 2003; October 3, 2005; March 29, 2006) near the city of Kharkiv (Ukraine) are presented. The effects observed in the morning, near-noon, and afternoon hours differed markedly. During the solar eclipses, the temperature of the surface atmosphere decreased by 1.3–7.3°. It was detected that, when the maximum value of the occultation function changed from 0.24 to 0.73, the standard deviation of solar-limb displacement σS decreased by 0.14″ and 0.68″, respectively. The time of convection development was found to be 15–16 min. The parameters of dynamic processes in the surface atmosphere have been calculated and the parameters of mechanical and thermal turbulence have been estimated from the results of measurements of the statistical characteristics of the level of solar-limb tremor with invocation of theoretical relations. The solar eclipses were accompanied by quasi-periodic processes in the atmosphere, which were most likely associated with the generation and propagation of internal gravity waves.
TL;DR: In this paper, a series of digital images of the solar disk and corona as well as of a near-sun sky area were collected during all phases of the 2006 total solar eclipse from an observation post located on the central line of totality near the town of Manavgat, Turkey.
TL;DR: In this paper, the mesosphere response to the solar eclipse (SE) event, which occurred on 29 March 2006, was analyzed using a periodogram method and the spectra of the observed wave-like oscillations, observed in the upper mesosphere, were examined.
TL;DR: In this paper, the radio emission of a high-latitude prominence located in the NE part of the solar limb was studied in the wavelength interval 1.03 ÷ 5.0 cm.
Abstract: The results of observations of the radio emission of a high-latitude prominence located in the NE part of the solar limb are discussed. Observations were performed on the radio telescope RATAN-600 using its Northeastern sector and Southern sector with a periscope during the maximum phase (0.998) of the solar eclipse of March 29, 2006. The prominence was studied in the wavelength interval 1.03 ÷ 5.0 cm. The absence of the background illumination from the solar disk allowed us to study the parameters of the radio emission of the high-latitude prominence (ϕ = 45°, NE limb of the Sun). Observations of the solar limb at the time of the maximum phase made it possible to record very small radio fluxes from the prominence, which amounted to 0.05 ÷ 0.01 s.f.u. in the wavelength interval from 1.84 to 5.0 cm. The position of the maximum of the radio emission of the prominence coincides, according to the results of observations performed on both sectors, with the summit of the prominence as seen on the solar image taken in the He II 304 A line (SOHO, ϕ = 45°, NE limb of the Sun).
TL;DR: The first experimental evidence for solar eclipse induced changes in the equatorial mesopause and the thermosphere ionosphere regions using a daytime optical photometer is presented in this article.
Abstract: [1] First experimental evidence for solar eclipse induced changes in the equatorial mesopause and the thermosphere ionosphere regions using daytime optical photometer is presented. The photometer was operated in scanning mode to probe the thermosphere and mesopause regions simultaneously in North-South direction over Trivandrum (8.5°N; 77°E; dip lat. 0.5°N) during a partial solar eclipse event on 03 October 2005. This provided a unique data set of thermosphere and mesopause regions over a horizontal distance of 600 and 240 km respectively from zenith during this event. The striking feature observed during the eclipse is the enhancement in the thermospheric O(1D) 630 nm dayglow intensity and its equatorward movement. Another noteworthy observation is an overall enhancement in the mesopause temperature, more pronounced (∼25–30 K) over zenith. These observations are discussed in context of the vertical coupling of the mesopause with thermosphere-ionosphere region.