Structure and Dynamics of the 2009 July 22 Eclipse White-Light Corona

Pasachoff, Jay M.; Rusin, V.; Санига, Метод; Druckmüllerová, Hana; Babcock, B. A.

doi:10.1088/0004-637x/742/1/29

Cited by 15 publications

(11 citation statements)

References 22 publications

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“…Our comparisons are similar in method to those we reported from pairs of observing sites at the 2006 eclipse (Pasachoff et al 2007(Pasachoff et al , 2008 from Greece; at the 2008 eclipse (Pasachoff et al 2009) from Siberia; at the 2009 eclipse (Pasachoff et al 2011b) from China; and at the 2010 eclipse (Pasachoff et al 2011a) from Easter Island. But only with this 2012 total solar eclipse did the Sun approach the maximum phase of the solar-activity cycle, so the corona was in a different configuration.…”

Section: Introductionsupporting

confidence: 86%

“…The behavior of large-scale solar coronal structures has been discussed, for example, by Rušin & Rybanský (1984), Koutchmy (1988), Zirker et al (1992), Pasachoff et al (2006Pasachoff et al ( , 2007Pasachoff et al ( , 2008Pasachoff et al ( , 2009Pasachoff et al ( , 2011aPasachoff et al ( , 2011b, Golub & Pasachoff (2010, Habbal et al (2013), and Druckmüller et al (2014). As the observing sites (Queensland and north of New Zealand) of the images in our comparison were 36 minutes apart in umbral travel time, comparing the corresponding data also enables us to discern interesting changes in the large-scale structure of the WLC on a temporal scale of half an hour.…”

Section: Dynamics Of the White-light Corona At Solar Maximummentioning

confidence: 99%

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Structure and Dynamics of the 2012 November 13/14 Eclipse White-Light Corona

Pasachoff

Rusin

Санига

et al. 2015

ApJ

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Continuing our series of observations of coronal motion and dynamics over the solar-activity cycle, we observed from sites in Queensland, Australia, during the 2012 November 13 (UT)/14 (local time) total solar eclipse. The corona took the low-ellipticity shape typical of solar maximum (flattening index ε = 0.01), a change from the composite coronal images we observed and analyzed in this journal and elsewhere for the 2006 and 2008-2010 eclipses. After crossing the northeast Australian coast, the path of totality was over the ocean, so further totality was seen only by shipborne observers. Our results include velocities of a coronal mass ejection (CME; during the 36 minutes of passage from the Queensland coast to a ship north of New Zealand, we measured 413 km s−1 ) and we analyze its dynamics. We discuss the shapes and positions of several types of coronal features seen on our higherresolution composite Queensland coronal images, including many helmet streamers, very faint bright and dark loops at the bases of helmet streamers, voids, and radially oriented thin streamers. We compare our eclipse observations with models of the magnetic field, confirming the validity of the predictions, and relate the eclipse phenomenology seen with the near-simultaneous images from NASA's Solar Dynamics Observatory (SDO/AIA), NASA's Extreme Ultraviolet Imager on Solar Terrestrial Relations Observatory, ESA/Royal Observatory of Belgium's Sun Watcher with Active Pixels and Image Processing (SWAP) on PROBA2, and Naval Research Laboratory's Large Angle and Spectrometric Coronagraph Experiment on ESA's Solar and Heliospheric Observatory. For example, the southeastern CME is related to the solar flare whose origin we trace with a SWAP series of images.

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Section: Introductionsupporting

confidence: 86%

Section: Dynamics Of the White-light Corona At Solar Maximummentioning

confidence: 99%

Structure and Dynamics of the 2012 November 13/14 Eclipse White-Light Corona

Pasachoff

Rusin

Санига

et al. 2015

ApJ

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“…The same variable conditions prevailed between third and fourth contacts and worsened afterward, including some rain. Even with the clouds, we were able to obtain and analyze images of the solar corona (Pasachoff et al, ). Figures are images taken by the Chinese geostationary meteorological satellite Fengyun 2‐D that show the cloudiness over the shadow path at 08:45, 09:15, and 09:45 local time, respectively.…”

Section: Cloudiness Evaluationmentioning

confidence: 99%

“…This image displays the cloudiness during totality (between 09:33:02.8 [9.55 a.m.] and 09:38:44.9 [9.65 a.m.]) at Tianhuangping. The clouds did not completely obstruct the view of the totally eclipsed solar disk; the Williams College expedition could observe the solar corona (Pasachoff et al, ). The sky had partly cleared up at the time of totality (not completely; we were looking through moving clouds, of course); however, stratocumulus and alto cumulus translucidus were observed (see also Figure ) around and close to the solar corona (photo by M. T. Roman).…”

Section: Cloudiness Evaluationmentioning

confidence: 99%

Cloudiness and Solar Radiation During the Longest Total Solar Eclipse of the 21st Century at Tianhuangping (Zhejiang), China

Peñaloza-Murillo

Pasachoff

2018

JGR Atmospheres

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The lack of comprehensive solar radiation monitoring during the longest total solar eclipse of the 21st century at Tianhuangping (Zhejiang), China, on 22 July 2009, has led to this investigation in order to evaluate the cloudiness contribution in estimating the impact on global solar radiation throughout this phenomenon. In doing so, we applied a cloud cover empirical model to obtain the global solar radiation and, at the same time, we deduced a theoretical model to get the direct solar radiation in which both the occultation and obscuration functions of this eclipse are included. We took limb darkening and atmospheric transmission into account. Though the weather during our eclipse observations agreed with the forecasts for that day, clouds and some rain, we were nonetheless able to observe all phases of the eclipse from our observation site at Tianhuangping. This experience suggests that for coming eclipses a record of the in situ observation protocol of cloudiness is mandatory. Our results for comparing global solar radiation models indicate that our total solar eclipse radiation model is quite acceptable and representative of that which could have happened at that time.Plain Language Summary A total solar eclipse is a situation where the Sun is obscured by the Moon viewed from Earth. In this particular arrangement in space a shadow is cast over a particular region. Thus, the ideal circumstances to observe a total solar eclipse are those in which the sky is cloudless in that region or zone. Yet from time to time this phenomenon occurs in the presence of interfering clouds preventing a direct observation of the event. However, under these adverse circumstances effects over the environment can still be felt and measured as, for example, the rapid reduction of solar energy reaching the surface. In that case such measurements would be lacking, but with some information about cloudiness one can have an idea of how the variation of this energy during the eclipse took place. In the procedure a quantitative knowledge of how the Moon disk is going to progressively cut the Sun's brightness during the eclipse is necessary. From an environmental point of view it is shown that a scientific observation of a total solar eclipse matters even though it was made under the influence of blocking clouds.

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“…Pasachoff et al (2011a) provide extensive coverage of coronal imaging of this eclipse from the same site on Easter Island, from Tatakoto in French Polynesia, and from several solar spacecraft. The solar-activity cycle had risen considerably since the China/Marshall-Islands observations of the 22 July 2009 total solar eclipse, for which the sunspot number was essentially zero (Pasachoff et al, 2011b).…”

Section: Figurementioning

confidence: 99%

Spectroscopic Coronal Observations During the Total Solar Eclipse of 11 July 2010

Voulgaris¹,

Gaintatzis

Seiradakis

et al. 2012

Sol Phys

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The flash spectra of the solar chromosphere and corona were measured with a slitless spectrograph before, after, and during the totality of the solar eclipse of 11 July 2010, at Easter Island, Chile. This eclipse took place at the beginning of the Solar Cycle 24, after an extended minimum of solar activity. The spectra taken during the eclipse show a different intensity ratio of the red and green coronal lines compared with those taken during the total solar eclipse of 1 August 2008, which took place toward the end of Solar Cycle 23. The characteristic coronal emission line of forbidden Fe XIV (5303 Å) was observed on the east and west solar limbs in four areas relatively symmetrically located with respect to the solar rotation axis. Subtraction of the continuum flash-spectrum background led to the identification of several extremely weak emission lines, including forbidden Ca XV (5694 Å), which is normally detected only in regions of very high excitation, e.g., during flares or above large sunspots. The height of the chromosphere was measured spectrophotometrically, using spectral lines from light elements and compared with the equivalent height of the lower chromosphere measured using spectral lines from heavy elements.

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Structure and Dynamics of the 2009 July 22 Eclipse White-Light Corona

Cited by 15 publications

References 22 publications

Structure and Dynamics of the 2012 November 13/14 Eclipse White-Light Corona

Structure and Dynamics of the 2012 November 13/14 Eclipse White-Light Corona

Cloudiness and Solar Radiation During the Longest Total Solar Eclipse of the 21st Century at Tianhuangping (Zhejiang), China

Spectroscopic Coronal Observations During the Total Solar Eclipse of 11 July 2010

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