Abstract

We report here on the observation of unpolarized (neutral) points in the sky during the total solar eclipse on 11 August 1999. Near the zenith a neutral point was observed at 450 nm at two different points of time during totality. Around this celestial point the distribution of the angle of polarization was heterogeneous: The electric field vectors on the one side were approximately perpendicular to those on the other side. At another moment of totality, near the zenith a local minimum of the degree of linear polarization occurred at 550 nm. Near the antisolar meridian, at a low elevation another two neutral points occurred at 450 nm at a certain moment during totality. Approximately at the position of these neutral points, at another moment of totality a local minimum of the degree of polarization occurred at 550 nm, whereas at 450 nm a neutral point was observed, around which the angle-of-polarization pattern was homogeneous: The electric field vectors were approximately horizontal on both sides of the neutral point.

© 2003 Optical Society of America

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  1. N. Piltschikoff, “Sur la polarisation du ciel pendant les éclipses du soleil,” C. R. Acad. Sci. Paris 142, 1449–1455 (1906).
  2. E. de Bary, K. Bullrich, D. Lorenz, “Messungen der Himmelsstrahlung und deren Polarisationsgrad während der Sonnenfinsternis am 15.2.1961 in Viareggio (Italien),” Geofis. Pura Appl. 48, 193–198 (1961).
    [CrossRef]
  3. J. G. Moore, C. R. N. Rao, “Polarization of the daytime sky during the total solar eclipse of 30 May 1965,” Ann. Geophys. 22, 147–150 (1966).
  4. B. S. Dandekar, J. P. Turtle, “Day sky brightness and polarization during the total solar eclipse of 7 March 1970,” Appl. Opt. 10, 1220–1224 (1971).
    [CrossRef] [PubMed]
  5. C. R. N. Rao, T. Takashima, J. G. Moore, “Polarimetry of the daytime sky during solar eclipses,” J. Atmos. Terr. Phys. 34, 573–576 (1972).
    [CrossRef]
  6. R. E. Miller, W. G. Fastie, “Skylight intensity, polarization and airglow measurements during the total solar eclipse of 30 May 1965,” J. Atmos. Terr. Phys. 34, 1541–1546 (1972).
    [CrossRef]
  7. K. L. Coulson, Polarization and Intensity of Light in the Atmosphere (Deepak, Hampton, Va., 1988).
  8. G. E. Shaw, “Sky brightness and polarization during the 1973 African eclipse,” Appl. Opt. 14, 388–394 (1975).
    [CrossRef] [PubMed]
  9. G. P. Können, “Skylight polarization during a total solar eclipse: a quantitative model,” J. Opt. Soc. Am. A 4, 601–608 (1987).
    [CrossRef]
  10. R. Gerharz, “Appearance of the atmospheric scatter field during a solar eclipse,” J. Geophys. 42, 163–167 (1976).
  11. J. A. North, M. J. Duggin, “Stokes vector imaging of the polarized sky-dome,” Appl. Opt. 36, 723–730 (1997).
    [CrossRef] [PubMed]
  12. K. J. Voss, Y. Liu, “Polarized radiance distribution measurements of skylight. I. System description and characterization,” Appl. Opt. 36, 6083–6094 (1997).
    [CrossRef] [PubMed]
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    [CrossRef]
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    [CrossRef]
  15. J. Gál, G. Horváth, V. B. Meyer-Rochow, “Measurement of the reflection-polarization pattern of the flat water surface under a clear sky at sunset,” Remote Sens. Environ. 76, 103–111 (2001).
    [CrossRef]
  16. I. Pomozi, J. Gál, G. Horváth, R. Wehner, “Fine structure of the celestial polarization pattern and its temporal change during the total solar eclipse of 11 August 1999,” Remote Sens. Environ. 76, 181–201 (2001).
    [CrossRef]
  17. I. Pomozi, G. Horváth, R. Wehner, “How the clear-sky angle of polarization pattern continues underneath clouds: full-sky measurements and implications for animal orientation,” J. Exp. Biol. 204, 2933–2942 (2001).
    [PubMed]
  18. J. Gál, G. Horváth, A. Barta, R. Wehner, “Polarization of the moonlit clear night sky measured by full-sky imaging polarimetry at full moon: comparison of the polarization of moonlit and sunlit skies,” J. Geophys. Res. D 106, 22647–22653 (2001).
    [CrossRef]
  19. G. Horváth, A. Barta, J. Gál, B. Suhai, O. Haiman, “Ground-based full-sky imaging polarimetry of rapidly changing skies and its use for polarimetric cloud detection,” Appl. Opt. 41, 543–559 (2002).
    [CrossRef] [PubMed]
  20. G. Horváth, J. Gál, I. Pomozi, R. Wehner, “Polarization portrait of the Arago point: video-polarimetric imaging of the neutral points of skylight polarization,” Naturwissenschaften 85, 333–339 (1998).
    [CrossRef]
  21. G. Horváth, R. Wehner, “Skylight polarization as perceived by desert ants and measured by video polarimetry,” J. Comp. Physiol. A 184, 1–7 (1999).
    [CrossRef]

2002

2001

J. Gál, G. Horváth, V. B. Meyer-Rochow, R. Wehner, “Polarization patterns of the summer sky and its neutral points measured by full-sky imaging polarimetry in Finnish Lapland north of the Arctic Circle,” Proc. R. Soc. London Ser. A 457, 1385–1399 (2001).
[CrossRef]

J. Gál, G. Horváth, V. B. Meyer-Rochow, “Measurement of the reflection-polarization pattern of the flat water surface under a clear sky at sunset,” Remote Sens. Environ. 76, 103–111 (2001).
[CrossRef]

I. Pomozi, J. Gál, G. Horváth, R. Wehner, “Fine structure of the celestial polarization pattern and its temporal change during the total solar eclipse of 11 August 1999,” Remote Sens. Environ. 76, 181–201 (2001).
[CrossRef]

I. Pomozi, G. Horváth, R. Wehner, “How the clear-sky angle of polarization pattern continues underneath clouds: full-sky measurements and implications for animal orientation,” J. Exp. Biol. 204, 2933–2942 (2001).
[PubMed]

J. Gál, G. Horváth, A. Barta, R. Wehner, “Polarization of the moonlit clear night sky measured by full-sky imaging polarimetry at full moon: comparison of the polarization of moonlit and sunlit skies,” J. Geophys. Res. D 106, 22647–22653 (2001).
[CrossRef]

1999

G. Horváth, R. Wehner, “Skylight polarization as perceived by desert ants and measured by video polarimetry,” J. Comp. Physiol. A 184, 1–7 (1999).
[CrossRef]

1998

G. Horváth, J. Gál, I. Pomozi, R. Wehner, “Polarization portrait of the Arago point: video-polarimetric imaging of the neutral points of skylight polarization,” Naturwissenschaften 85, 333–339 (1998).
[CrossRef]

1997

1987

1976

R. Gerharz, “Appearance of the atmospheric scatter field during a solar eclipse,” J. Geophys. 42, 163–167 (1976).

1975

1972

C. R. N. Rao, T. Takashima, J. G. Moore, “Polarimetry of the daytime sky during solar eclipses,” J. Atmos. Terr. Phys. 34, 573–576 (1972).
[CrossRef]

R. E. Miller, W. G. Fastie, “Skylight intensity, polarization and airglow measurements during the total solar eclipse of 30 May 1965,” J. Atmos. Terr. Phys. 34, 1541–1546 (1972).
[CrossRef]

1971

1966

J. G. Moore, C. R. N. Rao, “Polarization of the daytime sky during the total solar eclipse of 30 May 1965,” Ann. Geophys. 22, 147–150 (1966).

1961

E. de Bary, K. Bullrich, D. Lorenz, “Messungen der Himmelsstrahlung und deren Polarisationsgrad während der Sonnenfinsternis am 15.2.1961 in Viareggio (Italien),” Geofis. Pura Appl. 48, 193–198 (1961).
[CrossRef]

1906

N. Piltschikoff, “Sur la polarisation du ciel pendant les éclipses du soleil,” C. R. Acad. Sci. Paris 142, 1449–1455 (1906).

Barta, A.

G. Horváth, A. Barta, J. Gál, B. Suhai, O. Haiman, “Ground-based full-sky imaging polarimetry of rapidly changing skies and its use for polarimetric cloud detection,” Appl. Opt. 41, 543–559 (2002).
[CrossRef] [PubMed]

J. Gál, G. Horváth, A. Barta, R. Wehner, “Polarization of the moonlit clear night sky measured by full-sky imaging polarimetry at full moon: comparison of the polarization of moonlit and sunlit skies,” J. Geophys. Res. D 106, 22647–22653 (2001).
[CrossRef]

Bullrich, K.

E. de Bary, K. Bullrich, D. Lorenz, “Messungen der Himmelsstrahlung und deren Polarisationsgrad während der Sonnenfinsternis am 15.2.1961 in Viareggio (Italien),” Geofis. Pura Appl. 48, 193–198 (1961).
[CrossRef]

Coulson, K. L.

K. L. Coulson, Polarization and Intensity of Light in the Atmosphere (Deepak, Hampton, Va., 1988).

Dandekar, B. S.

de Bary, E.

E. de Bary, K. Bullrich, D. Lorenz, “Messungen der Himmelsstrahlung und deren Polarisationsgrad während der Sonnenfinsternis am 15.2.1961 in Viareggio (Italien),” Geofis. Pura Appl. 48, 193–198 (1961).
[CrossRef]

Duggin, M. J.

Fastie, W. G.

R. E. Miller, W. G. Fastie, “Skylight intensity, polarization and airglow measurements during the total solar eclipse of 30 May 1965,” J. Atmos. Terr. Phys. 34, 1541–1546 (1972).
[CrossRef]

Gál, J.

G. Horváth, A. Barta, J. Gál, B. Suhai, O. Haiman, “Ground-based full-sky imaging polarimetry of rapidly changing skies and its use for polarimetric cloud detection,” Appl. Opt. 41, 543–559 (2002).
[CrossRef] [PubMed]

J. Gál, G. Horváth, V. B. Meyer-Rochow, “Measurement of the reflection-polarization pattern of the flat water surface under a clear sky at sunset,” Remote Sens. Environ. 76, 103–111 (2001).
[CrossRef]

I. Pomozi, J. Gál, G. Horváth, R. Wehner, “Fine structure of the celestial polarization pattern and its temporal change during the total solar eclipse of 11 August 1999,” Remote Sens. Environ. 76, 181–201 (2001).
[CrossRef]

J. Gál, G. Horváth, V. B. Meyer-Rochow, R. Wehner, “Polarization patterns of the summer sky and its neutral points measured by full-sky imaging polarimetry in Finnish Lapland north of the Arctic Circle,” Proc. R. Soc. London Ser. A 457, 1385–1399 (2001).
[CrossRef]

J. Gál, G. Horváth, A. Barta, R. Wehner, “Polarization of the moonlit clear night sky measured by full-sky imaging polarimetry at full moon: comparison of the polarization of moonlit and sunlit skies,” J. Geophys. Res. D 106, 22647–22653 (2001).
[CrossRef]

G. Horváth, J. Gál, I. Pomozi, R. Wehner, “Polarization portrait of the Arago point: video-polarimetric imaging of the neutral points of skylight polarization,” Naturwissenschaften 85, 333–339 (1998).
[CrossRef]

Gerharz, R.

R. Gerharz, “Appearance of the atmospheric scatter field during a solar eclipse,” J. Geophys. 42, 163–167 (1976).

Haiman, O.

Horváth, G.

G. Horváth, A. Barta, J. Gál, B. Suhai, O. Haiman, “Ground-based full-sky imaging polarimetry of rapidly changing skies and its use for polarimetric cloud detection,” Appl. Opt. 41, 543–559 (2002).
[CrossRef] [PubMed]

I. Pomozi, G. Horváth, R. Wehner, “How the clear-sky angle of polarization pattern continues underneath clouds: full-sky measurements and implications for animal orientation,” J. Exp. Biol. 204, 2933–2942 (2001).
[PubMed]

J. Gál, G. Horváth, V. B. Meyer-Rochow, “Measurement of the reflection-polarization pattern of the flat water surface under a clear sky at sunset,” Remote Sens. Environ. 76, 103–111 (2001).
[CrossRef]

J. Gál, G. Horváth, A. Barta, R. Wehner, “Polarization of the moonlit clear night sky measured by full-sky imaging polarimetry at full moon: comparison of the polarization of moonlit and sunlit skies,” J. Geophys. Res. D 106, 22647–22653 (2001).
[CrossRef]

J. Gál, G. Horváth, V. B. Meyer-Rochow, R. Wehner, “Polarization patterns of the summer sky and its neutral points measured by full-sky imaging polarimetry in Finnish Lapland north of the Arctic Circle,” Proc. R. Soc. London Ser. A 457, 1385–1399 (2001).
[CrossRef]

I. Pomozi, J. Gál, G. Horváth, R. Wehner, “Fine structure of the celestial polarization pattern and its temporal change during the total solar eclipse of 11 August 1999,” Remote Sens. Environ. 76, 181–201 (2001).
[CrossRef]

G. Horváth, R. Wehner, “Skylight polarization as perceived by desert ants and measured by video polarimetry,” J. Comp. Physiol. A 184, 1–7 (1999).
[CrossRef]

G. Horváth, J. Gál, I. Pomozi, R. Wehner, “Polarization portrait of the Arago point: video-polarimetric imaging of the neutral points of skylight polarization,” Naturwissenschaften 85, 333–339 (1998).
[CrossRef]

Können, G. P.

Liu, Y.

Lorenz, D.

E. de Bary, K. Bullrich, D. Lorenz, “Messungen der Himmelsstrahlung und deren Polarisationsgrad während der Sonnenfinsternis am 15.2.1961 in Viareggio (Italien),” Geofis. Pura Appl. 48, 193–198 (1961).
[CrossRef]

Meyer-Rochow, V. B.

J. Gál, G. Horváth, V. B. Meyer-Rochow, “Measurement of the reflection-polarization pattern of the flat water surface under a clear sky at sunset,” Remote Sens. Environ. 76, 103–111 (2001).
[CrossRef]

J. Gál, G. Horváth, V. B. Meyer-Rochow, R. Wehner, “Polarization patterns of the summer sky and its neutral points measured by full-sky imaging polarimetry in Finnish Lapland north of the Arctic Circle,” Proc. R. Soc. London Ser. A 457, 1385–1399 (2001).
[CrossRef]

Miller, R. E.

R. E. Miller, W. G. Fastie, “Skylight intensity, polarization and airglow measurements during the total solar eclipse of 30 May 1965,” J. Atmos. Terr. Phys. 34, 1541–1546 (1972).
[CrossRef]

Moore, J. G.

C. R. N. Rao, T. Takashima, J. G. Moore, “Polarimetry of the daytime sky during solar eclipses,” J. Atmos. Terr. Phys. 34, 573–576 (1972).
[CrossRef]

J. G. Moore, C. R. N. Rao, “Polarization of the daytime sky during the total solar eclipse of 30 May 1965,” Ann. Geophys. 22, 147–150 (1966).

North, J. A.

Piltschikoff, N.

N. Piltschikoff, “Sur la polarisation du ciel pendant les éclipses du soleil,” C. R. Acad. Sci. Paris 142, 1449–1455 (1906).

Pomozi, I.

I. Pomozi, J. Gál, G. Horváth, R. Wehner, “Fine structure of the celestial polarization pattern and its temporal change during the total solar eclipse of 11 August 1999,” Remote Sens. Environ. 76, 181–201 (2001).
[CrossRef]

I. Pomozi, G. Horváth, R. Wehner, “How the clear-sky angle of polarization pattern continues underneath clouds: full-sky measurements and implications for animal orientation,” J. Exp. Biol. 204, 2933–2942 (2001).
[PubMed]

G. Horváth, J. Gál, I. Pomozi, R. Wehner, “Polarization portrait of the Arago point: video-polarimetric imaging of the neutral points of skylight polarization,” Naturwissenschaften 85, 333–339 (1998).
[CrossRef]

Rao, C. R. N.

C. R. N. Rao, T. Takashima, J. G. Moore, “Polarimetry of the daytime sky during solar eclipses,” J. Atmos. Terr. Phys. 34, 573–576 (1972).
[CrossRef]

J. G. Moore, C. R. N. Rao, “Polarization of the daytime sky during the total solar eclipse of 30 May 1965,” Ann. Geophys. 22, 147–150 (1966).

Shaw, G. E.

Suhai, B.

Takashima, T.

C. R. N. Rao, T. Takashima, J. G. Moore, “Polarimetry of the daytime sky during solar eclipses,” J. Atmos. Terr. Phys. 34, 573–576 (1972).
[CrossRef]

Turtle, J. P.

Voss, K. J.

Wehner, R.

J. Gál, G. Horváth, V. B. Meyer-Rochow, R. Wehner, “Polarization patterns of the summer sky and its neutral points measured by full-sky imaging polarimetry in Finnish Lapland north of the Arctic Circle,” Proc. R. Soc. London Ser. A 457, 1385–1399 (2001).
[CrossRef]

I. Pomozi, J. Gál, G. Horváth, R. Wehner, “Fine structure of the celestial polarization pattern and its temporal change during the total solar eclipse of 11 August 1999,” Remote Sens. Environ. 76, 181–201 (2001).
[CrossRef]

J. Gál, G. Horváth, A. Barta, R. Wehner, “Polarization of the moonlit clear night sky measured by full-sky imaging polarimetry at full moon: comparison of the polarization of moonlit and sunlit skies,” J. Geophys. Res. D 106, 22647–22653 (2001).
[CrossRef]

I. Pomozi, G. Horváth, R. Wehner, “How the clear-sky angle of polarization pattern continues underneath clouds: full-sky measurements and implications for animal orientation,” J. Exp. Biol. 204, 2933–2942 (2001).
[PubMed]

G. Horváth, R. Wehner, “Skylight polarization as perceived by desert ants and measured by video polarimetry,” J. Comp. Physiol. A 184, 1–7 (1999).
[CrossRef]

G. Horváth, J. Gál, I. Pomozi, R. Wehner, “Polarization portrait of the Arago point: video-polarimetric imaging of the neutral points of skylight polarization,” Naturwissenschaften 85, 333–339 (1998).
[CrossRef]

Ann. Geophys.

J. G. Moore, C. R. N. Rao, “Polarization of the daytime sky during the total solar eclipse of 30 May 1965,” Ann. Geophys. 22, 147–150 (1966).

Appl. Opt.

C. R. Acad. Sci. Paris

N. Piltschikoff, “Sur la polarisation du ciel pendant les éclipses du soleil,” C. R. Acad. Sci. Paris 142, 1449–1455 (1906).

Geofis. Pura Appl.

E. de Bary, K. Bullrich, D. Lorenz, “Messungen der Himmelsstrahlung und deren Polarisationsgrad während der Sonnenfinsternis am 15.2.1961 in Viareggio (Italien),” Geofis. Pura Appl. 48, 193–198 (1961).
[CrossRef]

J. Atmos. Terr. Phys.

C. R. N. Rao, T. Takashima, J. G. Moore, “Polarimetry of the daytime sky during solar eclipses,” J. Atmos. Terr. Phys. 34, 573–576 (1972).
[CrossRef]

R. E. Miller, W. G. Fastie, “Skylight intensity, polarization and airglow measurements during the total solar eclipse of 30 May 1965,” J. Atmos. Terr. Phys. 34, 1541–1546 (1972).
[CrossRef]

J. Comp. Physiol. A

G. Horváth, R. Wehner, “Skylight polarization as perceived by desert ants and measured by video polarimetry,” J. Comp. Physiol. A 184, 1–7 (1999).
[CrossRef]

J. Exp. Biol.

I. Pomozi, G. Horváth, R. Wehner, “How the clear-sky angle of polarization pattern continues underneath clouds: full-sky measurements and implications for animal orientation,” J. Exp. Biol. 204, 2933–2942 (2001).
[PubMed]

J. Geophys.

R. Gerharz, “Appearance of the atmospheric scatter field during a solar eclipse,” J. Geophys. 42, 163–167 (1976).

J. Geophys. Res. D

J. Gál, G. Horváth, A. Barta, R. Wehner, “Polarization of the moonlit clear night sky measured by full-sky imaging polarimetry at full moon: comparison of the polarization of moonlit and sunlit skies,” J. Geophys. Res. D 106, 22647–22653 (2001).
[CrossRef]

J. Opt. Soc. Am. A

Naturwissenschaften

G. Horváth, J. Gál, I. Pomozi, R. Wehner, “Polarization portrait of the Arago point: video-polarimetric imaging of the neutral points of skylight polarization,” Naturwissenschaften 85, 333–339 (1998).
[CrossRef]

Proc. R. Soc. London Ser. A

J. Gál, G. Horváth, V. B. Meyer-Rochow, R. Wehner, “Polarization patterns of the summer sky and its neutral points measured by full-sky imaging polarimetry in Finnish Lapland north of the Arctic Circle,” Proc. R. Soc. London Ser. A 457, 1385–1399 (2001).
[CrossRef]

Remote Sens. Environ.

J. Gál, G. Horváth, V. B. Meyer-Rochow, “Measurement of the reflection-polarization pattern of the flat water surface under a clear sky at sunset,” Remote Sens. Environ. 76, 103–111 (2001).
[CrossRef]

I. Pomozi, J. Gál, G. Horváth, R. Wehner, “Fine structure of the celestial polarization pattern and its temporal change during the total solar eclipse of 11 August 1999,” Remote Sens. Environ. 76, 181–201 (2001).
[CrossRef]

Other

K. L. Coulson, Polarization and Intensity of Light in the Atmosphere (Deepak, Hampton, Va., 1988).

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Figures (18)

Fig. 1
Fig. 1

Map of Hungary showing the path and shape of the umbra during the total solar eclipse on 11 August 1999. Our full-sky imaging polarimetric measurements were performed at Kecel, Hungary.

Fig. 2
Fig. 2

Trajectory of the observer through the umbra of the total eclipse on 11 August 1999 with filled dots where and when our polarimetric measurements were taken. Open dots represent the second and the third contact as well as the midtotality.

Fig. 3
Fig. 3

Celestial pattern of the degree of linear polarization p of skylight measured by full-sky imaging polarimetry at wavelength 550 nm (green) at 13:01:00 (local summer time, UTC + 2) on 11 August 1999 in Kecel, 7 min after the end of totality (third contact, 12:53:56; Fig. 2) of the solar eclipse, when the geometrical obscuration of the Sun’s disk was 89%. The position of the Sun (S) is indicated by a dot, and the estimated positions of the Babinet and the Brewster neutral points are marked with Ba and Br, respectively. The radial bar approximately parallel to the solar meridian comes from the Sun occulter (a wire holding a small disk). The graphs of Figs. 4 and 6 below are measured along the antisolar meridian indicated by an arrow in the circular pattern. East (West) is on the left (right) rather than on the right (left) of the compass rose, because we are looking up through the celestial dome rather than down onto a map.

Fig. 4
Fig. 4

Graph of the degree of linear polarization p along the antisolar meridian indicated by an arrow in the circular pattern of Fig. 3. The solid curve represents the curve fitted by the method of least squares to the measured values of p, and the dashed curves show the upper and the lower limits, between which 90% of the p values fall. In the graph the vegetation near the horizon is indicated by gray shading.

Fig. 5
Fig. 5

As in Fig. 3 for the angle of polarization α of skylight with respect to the local meridian.

Fig. 6
Fig. 6

As in Fig. 4 for the angle of polarization α (with respect to the local meridian) along the antisolar meridian indicated by an arrow in the circular pattern of Fig. 5.

Fig. 7
Fig. 7

Celestial pattern of the degree of linear polarization p of skylight measured with full-sky imaging polarimetry during totality of the eclipse on 11 August 1999 in Kecel at 12:51:34 (local summer time, UTC + 2) and 450 nm (blue). The p values are rounded to integers (0, 1, 2, 3, …, 100%). The neutral points are marked by dots.

Fig. 8
Fig. 8

As in Fig. 7 at 12:52:00.

Fig. 9
Fig. 9

As in Fig. 8 at 550 nm (green).

Fig. 10
Fig. 10

As in Fig. 7 for the angle of polarization α of skylight measured from the local meridian.

Fig. 11
Fig. 11

As in Fig. 10 at 12:52:00.

Fig. 12
Fig. 12

As in Fig. 11 at 550 nm (green).

Fig. 13
Fig. 13

Graphs of the degree of linear polarization p measured along different meridians crossing the zenith Z of the eclipse sky at 12:51:34 (UTC + 2) and 450 nm. The solid curves represent the curves fitted by the method of least squares to the measured p values, and the dashed curves show the upper and the lower limits, between which 90% of the p values falls. The circular insets show how the scans are located with respect to the pattern in Fig. 3. (A) Scan through the two neutral points N1 of type 1 near the horizon. (B) Scan through the neutral point N2 of type 2 near the zenith.

Fig. 14
Fig. 14

As in Fig. 13 for 12:52:00. (A) Scan through the neutral point N3 of type 3 near the horizon. (B) Scan through the neutral point N2 of type 2 near the zenith.

Fig. 15
Fig. 15

As in Fig. 14 for 550 nm. (A) Scan through the local minimum MH of p near the horizon. (B) Scan through the local minimum MZ of p near zenith.

Fig. 16
Fig. 16

As in Fig. 13 for the angle of polarization α.

Fig. 17
Fig. 17

As in Fig. 14 for the angle of polarization α.

Fig. 18
Fig. 18

As in Fig. 15 for the angle of polarization α.

Tables (2)

Tables Icon

Table 1 Summary of Instrumental Observations of the Degree of Linear Polarization of Skylight at Mideclipse Measured at 90° from the Eclipsed Sun in the Sun’s Vertical (apart from Gerharza)b

Tables Icon

Table 2 Zenith Angles θ and Azimuth Angles φ (Measured Counterclockwise from the West, for the Antisolar Meridian: φ = 79°) of the Local Minima of the Degree of Linear Polarization p and the Neutral Points of Skylight Polarizationa

Metrics