Abstract

The effects of forest fire smoke on sky polarization and animal orientation are practically unknown. Using full-sky imaging polarimetry, we therefore measured the celestial polarization pattern under a smoky sky in Fairbanks, Alaska, during the forest fire season in August 2005. It is quantitatively documented here that the celestial polarization, a sky attribute that is necessary for orientation of many polarization-sensitive animal species, above Fairbanks on 17 August 2005 was in several aspects anomalous due to the forest fire smoke: (i) The pattern of the degree of linear polarization p of the reddish smoky sky differed considerably from that of the corresponding clear blue sky. (ii) Due to the smoke, p of skylight was drastically reduced (pmax14%, paverage8%). (iii) Depending on wavelength and time, the Arago, Babinet, and Brewster neutral points of sky polarization had anomalous positions. We suggest that the disorientation of certain insects observed by Canadian researchers under smoky skies during the forest fire season in August 2003 in British Columbia was the consequence of the anomalous sky polarization caused by the forest fire smoke.

© 2007 Optical Society of America

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References

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  1. Y. J. Kaufman, D. Tanré, and O. Boucher, "A satellite view of aerosols in the climate system," Nature 419, 215-223 (2002).
    [CrossRef] [PubMed]
  2. D. F. Yefremov and A. Z. Shvidenko, "Long-term environmental impact of catastrophic forest fires in Russia's Far East and their contribution to global processes," Int. Forest Fire News 32, 43-49 (2004).
  3. F. M. Bréon, "How do aerosols affect cloudiness and climate?" Science 313, 623-624 (2006).
    [CrossRef] [PubMed]
  4. Y. J. Kaufman and I. Koren, "Smoke and pollution aerosol effect on cloud cover," Science 313, 655-658 (2006).
    [CrossRef] [PubMed]
  5. E. S. Kasischke and B. J. Stocks, eds., Fire, Climate Change and Carbon Cycling in the Boreal Forest, Ecological Studies Series (Springer-Verlag, 2000).
  6. S. E. Page, F. Seigert, J. O. Rieley, H.-D. Boehm, A. Jaya, and S. Limin, "The amount of carbon released from peat and forest fires in Indonesia during 1997," Nature 420, 61-65 (2002).
    [CrossRef] [PubMed]
  7. M. A. Cochrane, "Fire science for rainforests," Nature 421, 913-919 (2003).
    [CrossRef] [PubMed]
  8. P. Aldhous, "Borneo is burning," Nature 432, 144-146 (2004).
    [CrossRef] [PubMed]
  9. E. A. Johnson and K. Miyanishi, Forest Fires: Behavior and Ecological Effect (Academic, 2000).
  10. K. L. Coulson, Polarization and Intensity of Light in the Atmosphere (A. Deepak Publishing, 1988).
  11. K. L. Coulson, "Characteristics of skylight at the zenith during twilight as indicators of atmospheric turbidity. 1: Degree of polarization," Appl. Opt. 19, 3469-3480 (1980).
    [CrossRef] [PubMed]
  12. K. L. Coulson, "Effects of the El Chichon volcanic cloud in the stratosphere on the polarization of light from the sky," Appl. Opt. 22, 2265-2271 (1983).
    [CrossRef] [PubMed]
  13. H. Neuberger, "Arago's neutral point: a neglected tool in meteorological research," Bull. Am. Meteorol. Soc. 31, 119-125 (1950).
  14. G. Steinhorst, "Stratospheric aerosol concentration determined by an iterative method from twilight polarization measurements," Beit. Phys. Atmos. 50, 508-523 (1977).
  15. F. E. Volz, "Volcanic turbidity, skylight scattering functions, sky polarization, and twilights in New England during 1983," Appl. Opt. 23, 2589-2598 (1984).
    [CrossRef] [PubMed]
  16. R. Wehner, "Arthropods," in Animal Homing, F.Papi, ed. (Chapman & Hall, 1992), p. 45-144.
    [CrossRef]
  17. G. Horváth and D. Varjú, Polarized Light in Animal Vision--Polarization Patterns in Nature (Springer-Verlag, 2003).
  18. R. Muheim, J. B. Phillips, and S. Åkesson, "Polarized light cues underlie compass calibration in migratory songbirds," Science 313, 837-839 (2006).
    [CrossRef] [PubMed]
  19. D. L. Johnson, D. Naylor, and G. Scudder, "Red sky in day, bugs go astray," Annual Meeting of the Canadian Association of Geographers, Western Division, Lethbridge, Alberta, Canada, 12 March 2005, Abstracts (2005), p. 45.
  20. J. Gál, G. Horváth, V. B. Meyer-Rochow, and 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]
  21. M. V. Berry, M. R. Dennis, and R. L. Lee Jr., "Polarization singularities in the clear sky," New J. Phys. 6, 162 (2004).
    [CrossRef]
  22. G. P. Können, Polarized Light in Nature (Cambridge U. Press, 1985).
  23. A. Cornu, "Observations relatives a la couronne visible actuellement autour du soleil," C. R. Acad. Sci. Paris 99, 488-493 (1884).
  24. H. H. Kimball, "The effect of the atmospheric turbidity of 1912 on solar radiation intensities and skylight polarization," Bull. Meteorological Weather Observatory 5, 295-312 (1913).
  25. C. Dorno, "Himmelshelligkeit, Himmelspolarisation und Sonnenintensität in Davos (1911 bis 1918). I," Meteorologische Zeit. 36, 109-128 (1919).
  26. C. Dorno, "Himmelshelligkeit, Himmelspolarisation und Sonnenintensität in Davos (1911 bis 1918). II," Meteorologische Zeit. 36, 181-192 (1919).
  27. C. Jensen, "Die Himmelsstrahlung," in Handbuch der Physik (Springer, 1928), Vol. 19, p. 70-152.
  28. C. Jensen, "Die Polarisation des Himmelslichts," in Handbuch der Geophysik (Springer, 1942), Vol. 8, p. 527-620.
  29. G. M. Shah, "Enhanced twilight glow caused by the volcanic eruption on Bali Island in March and September, 1963," Tellus 21, 636-640 (1969).
    [CrossRef]
  30. J. L. Soret, "Influences des surfaces d'eau sur la polarisation atmospherique et observation de deux points neutres a droite et a gauche de soleil," C. R. Acad. Sci. Paris 107, 867-870 (1888).
  31. T. Alerstam, A. Hedenström, and S. Åkesson, "Long-distance migration: evolution and determinants," Oikos 103, 247-260 (2003).
    [CrossRef]
  32. J. Gál, G. Horváth, A. Barta, and 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]

2006 (3)

F. M. Bréon, "How do aerosols affect cloudiness and climate?" Science 313, 623-624 (2006).
[CrossRef] [PubMed]

Y. J. Kaufman and I. Koren, "Smoke and pollution aerosol effect on cloud cover," Science 313, 655-658 (2006).
[CrossRef] [PubMed]

R. Muheim, J. B. Phillips, and S. Åkesson, "Polarized light cues underlie compass calibration in migratory songbirds," Science 313, 837-839 (2006).
[CrossRef] [PubMed]

2004 (3)

M. V. Berry, M. R. Dennis, and R. L. Lee Jr., "Polarization singularities in the clear sky," New J. Phys. 6, 162 (2004).
[CrossRef]

D. F. Yefremov and A. Z. Shvidenko, "Long-term environmental impact of catastrophic forest fires in Russia's Far East and their contribution to global processes," Int. Forest Fire News 32, 43-49 (2004).

P. Aldhous, "Borneo is burning," Nature 432, 144-146 (2004).
[CrossRef] [PubMed]

2003 (2)

M. A. Cochrane, "Fire science for rainforests," Nature 421, 913-919 (2003).
[CrossRef] [PubMed]

T. Alerstam, A. Hedenström, and S. Åkesson, "Long-distance migration: evolution and determinants," Oikos 103, 247-260 (2003).
[CrossRef]

2002 (2)

Y. J. Kaufman, D. Tanré, and O. Boucher, "A satellite view of aerosols in the climate system," Nature 419, 215-223 (2002).
[CrossRef] [PubMed]

S. E. Page, F. Seigert, J. O. Rieley, H.-D. Boehm, A. Jaya, and S. Limin, "The amount of carbon released from peat and forest fires in Indonesia during 1997," Nature 420, 61-65 (2002).
[CrossRef] [PubMed]

2001 (2)

J. Gál, G. Horváth, V. B. Meyer-Rochow, and 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, and 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]

1984 (1)

1983 (1)

1980 (1)

1977 (1)

G. Steinhorst, "Stratospheric aerosol concentration determined by an iterative method from twilight polarization measurements," Beit. Phys. Atmos. 50, 508-523 (1977).

1969 (1)

G. M. Shah, "Enhanced twilight glow caused by the volcanic eruption on Bali Island in March and September, 1963," Tellus 21, 636-640 (1969).
[CrossRef]

1950 (1)

H. Neuberger, "Arago's neutral point: a neglected tool in meteorological research," Bull. Am. Meteorol. Soc. 31, 119-125 (1950).

1919 (2)

C. Dorno, "Himmelshelligkeit, Himmelspolarisation und Sonnenintensität in Davos (1911 bis 1918). I," Meteorologische Zeit. 36, 109-128 (1919).

C. Dorno, "Himmelshelligkeit, Himmelspolarisation und Sonnenintensität in Davos (1911 bis 1918). II," Meteorologische Zeit. 36, 181-192 (1919).

1913 (1)

H. H. Kimball, "The effect of the atmospheric turbidity of 1912 on solar radiation intensities and skylight polarization," Bull. Meteorological Weather Observatory 5, 295-312 (1913).

1888 (1)

J. L. Soret, "Influences des surfaces d'eau sur la polarisation atmospherique et observation de deux points neutres a droite et a gauche de soleil," C. R. Acad. Sci. Paris 107, 867-870 (1888).

1884 (1)

A. Cornu, "Observations relatives a la couronne visible actuellement autour du soleil," C. R. Acad. Sci. Paris 99, 488-493 (1884).

Åkesson, S.

R. Muheim, J. B. Phillips, and S. Åkesson, "Polarized light cues underlie compass calibration in migratory songbirds," Science 313, 837-839 (2006).
[CrossRef] [PubMed]

T. Alerstam, A. Hedenström, and S. Åkesson, "Long-distance migration: evolution and determinants," Oikos 103, 247-260 (2003).
[CrossRef]

Aldhous, P.

P. Aldhous, "Borneo is burning," Nature 432, 144-146 (2004).
[CrossRef] [PubMed]

Alerstam, T.

T. Alerstam, A. Hedenström, and S. Åkesson, "Long-distance migration: evolution and determinants," Oikos 103, 247-260 (2003).
[CrossRef]

Barta, A.

J. Gál, G. Horváth, A. Barta, and 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]

Berry, M. V.

M. V. Berry, M. R. Dennis, and R. L. Lee Jr., "Polarization singularities in the clear sky," New J. Phys. 6, 162 (2004).
[CrossRef]

Boehm, H.-D.

S. E. Page, F. Seigert, J. O. Rieley, H.-D. Boehm, A. Jaya, and S. Limin, "The amount of carbon released from peat and forest fires in Indonesia during 1997," Nature 420, 61-65 (2002).
[CrossRef] [PubMed]

Boucher, O.

Y. J. Kaufman, D. Tanré, and O. Boucher, "A satellite view of aerosols in the climate system," Nature 419, 215-223 (2002).
[CrossRef] [PubMed]

Bréon, F. M.

F. M. Bréon, "How do aerosols affect cloudiness and climate?" Science 313, 623-624 (2006).
[CrossRef] [PubMed]

Cochrane, M. A.

M. A. Cochrane, "Fire science for rainforests," Nature 421, 913-919 (2003).
[CrossRef] [PubMed]

Cornu, A.

A. Cornu, "Observations relatives a la couronne visible actuellement autour du soleil," C. R. Acad. Sci. Paris 99, 488-493 (1884).

Coulson, K. L.

Dennis, M. R.

M. V. Berry, M. R. Dennis, and R. L. Lee Jr., "Polarization singularities in the clear sky," New J. Phys. 6, 162 (2004).
[CrossRef]

Dorno, C.

C. Dorno, "Himmelshelligkeit, Himmelspolarisation und Sonnenintensität in Davos (1911 bis 1918). I," Meteorologische Zeit. 36, 109-128 (1919).

C. Dorno, "Himmelshelligkeit, Himmelspolarisation und Sonnenintensität in Davos (1911 bis 1918). II," Meteorologische Zeit. 36, 181-192 (1919).

Gál, J.

J. Gál, G. Horváth, A. Barta, and 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, and 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]

Hedenström, A.

T. Alerstam, A. Hedenström, and S. Åkesson, "Long-distance migration: evolution and determinants," Oikos 103, 247-260 (2003).
[CrossRef]

Horváth, G.

J. Gál, G. Horváth, A. Barta, and 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, and 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]

G. Horváth and D. Varjú, Polarized Light in Animal Vision--Polarization Patterns in Nature (Springer-Verlag, 2003).

Jaya, A.

S. E. Page, F. Seigert, J. O. Rieley, H.-D. Boehm, A. Jaya, and S. Limin, "The amount of carbon released from peat and forest fires in Indonesia during 1997," Nature 420, 61-65 (2002).
[CrossRef] [PubMed]

Jensen, C.

C. Jensen, "Die Himmelsstrahlung," in Handbuch der Physik (Springer, 1928), Vol. 19, p. 70-152.

C. Jensen, "Die Polarisation des Himmelslichts," in Handbuch der Geophysik (Springer, 1942), Vol. 8, p. 527-620.

Johnson, D. L.

D. L. Johnson, D. Naylor, and G. Scudder, "Red sky in day, bugs go astray," Annual Meeting of the Canadian Association of Geographers, Western Division, Lethbridge, Alberta, Canada, 12 March 2005, Abstracts (2005), p. 45.

Johnson, E. A.

E. A. Johnson and K. Miyanishi, Forest Fires: Behavior and Ecological Effect (Academic, 2000).

Kasischke, E. S.

E. S. Kasischke and B. J. Stocks, eds., Fire, Climate Change and Carbon Cycling in the Boreal Forest, Ecological Studies Series (Springer-Verlag, 2000).

Kaufman, Y. J.

Y. J. Kaufman and I. Koren, "Smoke and pollution aerosol effect on cloud cover," Science 313, 655-658 (2006).
[CrossRef] [PubMed]

Y. J. Kaufman, D. Tanré, and O. Boucher, "A satellite view of aerosols in the climate system," Nature 419, 215-223 (2002).
[CrossRef] [PubMed]

Kimball, H. H.

H. H. Kimball, "The effect of the atmospheric turbidity of 1912 on solar radiation intensities and skylight polarization," Bull. Meteorological Weather Observatory 5, 295-312 (1913).

Können, G. P.

G. P. Können, Polarized Light in Nature (Cambridge U. Press, 1985).

Koren, I.

Y. J. Kaufman and I. Koren, "Smoke and pollution aerosol effect on cloud cover," Science 313, 655-658 (2006).
[CrossRef] [PubMed]

Lee, R. L.

M. V. Berry, M. R. Dennis, and R. L. Lee Jr., "Polarization singularities in the clear sky," New J. Phys. 6, 162 (2004).
[CrossRef]

Limin, S.

S. E. Page, F. Seigert, J. O. Rieley, H.-D. Boehm, A. Jaya, and S. Limin, "The amount of carbon released from peat and forest fires in Indonesia during 1997," Nature 420, 61-65 (2002).
[CrossRef] [PubMed]

Meyer-Rochow, V. B.

J. Gál, G. Horváth, V. B. Meyer-Rochow, and 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]

Miyanishi, K.

E. A. Johnson and K. Miyanishi, Forest Fires: Behavior and Ecological Effect (Academic, 2000).

Muheim, R.

R. Muheim, J. B. Phillips, and S. Åkesson, "Polarized light cues underlie compass calibration in migratory songbirds," Science 313, 837-839 (2006).
[CrossRef] [PubMed]

Naylor, D.

D. L. Johnson, D. Naylor, and G. Scudder, "Red sky in day, bugs go astray," Annual Meeting of the Canadian Association of Geographers, Western Division, Lethbridge, Alberta, Canada, 12 March 2005, Abstracts (2005), p. 45.

Neuberger, H.

H. Neuberger, "Arago's neutral point: a neglected tool in meteorological research," Bull. Am. Meteorol. Soc. 31, 119-125 (1950).

Page, S. E.

S. E. Page, F. Seigert, J. O. Rieley, H.-D. Boehm, A. Jaya, and S. Limin, "The amount of carbon released from peat and forest fires in Indonesia during 1997," Nature 420, 61-65 (2002).
[CrossRef] [PubMed]

Phillips, J. B.

R. Muheim, J. B. Phillips, and S. Åkesson, "Polarized light cues underlie compass calibration in migratory songbirds," Science 313, 837-839 (2006).
[CrossRef] [PubMed]

Rieley, J. O.

S. E. Page, F. Seigert, J. O. Rieley, H.-D. Boehm, A. Jaya, and S. Limin, "The amount of carbon released from peat and forest fires in Indonesia during 1997," Nature 420, 61-65 (2002).
[CrossRef] [PubMed]

Scudder, G.

D. L. Johnson, D. Naylor, and G. Scudder, "Red sky in day, bugs go astray," Annual Meeting of the Canadian Association of Geographers, Western Division, Lethbridge, Alberta, Canada, 12 March 2005, Abstracts (2005), p. 45.

Seigert, F.

S. E. Page, F. Seigert, J. O. Rieley, H.-D. Boehm, A. Jaya, and S. Limin, "The amount of carbon released from peat and forest fires in Indonesia during 1997," Nature 420, 61-65 (2002).
[CrossRef] [PubMed]

Shah, G. M.

G. M. Shah, "Enhanced twilight glow caused by the volcanic eruption on Bali Island in March and September, 1963," Tellus 21, 636-640 (1969).
[CrossRef]

Shvidenko, A. Z.

D. F. Yefremov and A. Z. Shvidenko, "Long-term environmental impact of catastrophic forest fires in Russia's Far East and their contribution to global processes," Int. Forest Fire News 32, 43-49 (2004).

Soret, J. L.

J. L. Soret, "Influences des surfaces d'eau sur la polarisation atmospherique et observation de deux points neutres a droite et a gauche de soleil," C. R. Acad. Sci. Paris 107, 867-870 (1888).

Steinhorst, G.

G. Steinhorst, "Stratospheric aerosol concentration determined by an iterative method from twilight polarization measurements," Beit. Phys. Atmos. 50, 508-523 (1977).

Stocks, B. J.

E. S. Kasischke and B. J. Stocks, eds., Fire, Climate Change and Carbon Cycling in the Boreal Forest, Ecological Studies Series (Springer-Verlag, 2000).

Tanré, D.

Y. J. Kaufman, D. Tanré, and O. Boucher, "A satellite view of aerosols in the climate system," Nature 419, 215-223 (2002).
[CrossRef] [PubMed]

Varjú, D.

G. Horváth and D. Varjú, Polarized Light in Animal Vision--Polarization Patterns in Nature (Springer-Verlag, 2003).

Volz, F. E.

Wehner, R.

J. Gál, G. Horváth, V. B. Meyer-Rochow, and 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, and 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]

R. Wehner, "Arthropods," in Animal Homing, F.Papi, ed. (Chapman & Hall, 1992), p. 45-144.
[CrossRef]

Yefremov, D. F.

D. F. Yefremov and A. Z. Shvidenko, "Long-term environmental impact of catastrophic forest fires in Russia's Far East and their contribution to global processes," Int. Forest Fire News 32, 43-49 (2004).

Appl. Opt. (3)

Beit. Phys. Atmos. (1)

G. Steinhorst, "Stratospheric aerosol concentration determined by an iterative method from twilight polarization measurements," Beit. Phys. Atmos. 50, 508-523 (1977).

Bull. Am. Meteorol. Soc. (1)

H. Neuberger, "Arago's neutral point: a neglected tool in meteorological research," Bull. Am. Meteorol. Soc. 31, 119-125 (1950).

Bull. Meteorological Weather Observatory (1)

H. H. Kimball, "The effect of the atmospheric turbidity of 1912 on solar radiation intensities and skylight polarization," Bull. Meteorological Weather Observatory 5, 295-312 (1913).

C. R. Acad. Sci. Paris (2)

A. Cornu, "Observations relatives a la couronne visible actuellement autour du soleil," C. R. Acad. Sci. Paris 99, 488-493 (1884).

J. L. Soret, "Influences des surfaces d'eau sur la polarisation atmospherique et observation de deux points neutres a droite et a gauche de soleil," C. R. Acad. Sci. Paris 107, 867-870 (1888).

Int. Forest Fire News (1)

D. F. Yefremov and A. Z. Shvidenko, "Long-term environmental impact of catastrophic forest fires in Russia's Far East and their contribution to global processes," Int. Forest Fire News 32, 43-49 (2004).

J. Geophys. Res. D (1)

J. Gál, G. Horváth, A. Barta, and 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]

Meteorologische Zeit. (2)

C. Dorno, "Himmelshelligkeit, Himmelspolarisation und Sonnenintensität in Davos (1911 bis 1918). I," Meteorologische Zeit. 36, 109-128 (1919).

C. Dorno, "Himmelshelligkeit, Himmelspolarisation und Sonnenintensität in Davos (1911 bis 1918). II," Meteorologische Zeit. 36, 181-192 (1919).

Nature (4)

S. E. Page, F. Seigert, J. O. Rieley, H.-D. Boehm, A. Jaya, and S. Limin, "The amount of carbon released from peat and forest fires in Indonesia during 1997," Nature 420, 61-65 (2002).
[CrossRef] [PubMed]

M. A. Cochrane, "Fire science for rainforests," Nature 421, 913-919 (2003).
[CrossRef] [PubMed]

P. Aldhous, "Borneo is burning," Nature 432, 144-146 (2004).
[CrossRef] [PubMed]

Y. J. Kaufman, D. Tanré, and O. Boucher, "A satellite view of aerosols in the climate system," Nature 419, 215-223 (2002).
[CrossRef] [PubMed]

New J. Phys. (1)

M. V. Berry, M. R. Dennis, and R. L. Lee Jr., "Polarization singularities in the clear sky," New J. Phys. 6, 162 (2004).
[CrossRef]

Oikos (1)

T. Alerstam, A. Hedenström, and S. Åkesson, "Long-distance migration: evolution and determinants," Oikos 103, 247-260 (2003).
[CrossRef]

Proc. R. Soc. London Ser. A (1)

J. Gál, G. Horváth, V. B. Meyer-Rochow, and 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]

Science (3)

R. Muheim, J. B. Phillips, and S. Åkesson, "Polarized light cues underlie compass calibration in migratory songbirds," Science 313, 837-839 (2006).
[CrossRef] [PubMed]

F. M. Bréon, "How do aerosols affect cloudiness and climate?" Science 313, 623-624 (2006).
[CrossRef] [PubMed]

Y. J. Kaufman and I. Koren, "Smoke and pollution aerosol effect on cloud cover," Science 313, 655-658 (2006).
[CrossRef] [PubMed]

Tellus (1)

G. M. Shah, "Enhanced twilight glow caused by the volcanic eruption on Bali Island in March and September, 1963," Tellus 21, 636-640 (1969).
[CrossRef]

Other (9)

G. P. Können, Polarized Light in Nature (Cambridge U. Press, 1985).

C. Jensen, "Die Himmelsstrahlung," in Handbuch der Physik (Springer, 1928), Vol. 19, p. 70-152.

C. Jensen, "Die Polarisation des Himmelslichts," in Handbuch der Geophysik (Springer, 1942), Vol. 8, p. 527-620.

E. S. Kasischke and B. J. Stocks, eds., Fire, Climate Change and Carbon Cycling in the Boreal Forest, Ecological Studies Series (Springer-Verlag, 2000).

E. A. Johnson and K. Miyanishi, Forest Fires: Behavior and Ecological Effect (Academic, 2000).

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

D. L. Johnson, D. Naylor, and G. Scudder, "Red sky in day, bugs go astray," Annual Meeting of the Canadian Association of Geographers, Western Division, Lethbridge, Alberta, Canada, 12 March 2005, Abstracts (2005), p. 45.

R. Wehner, "Arthropods," in Animal Homing, F.Papi, ed. (Chapman & Hall, 1992), p. 45-144.
[CrossRef]

G. Horváth and D. Varjú, Polarized Light in Animal Vision--Polarization Patterns in Nature (Springer-Verlag, 2003).

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Figures (5)

Fig. 1
Fig. 1

(Color online) Photograph of the reddish, smoky sky taken at the airport of Fairbanks on 17 August 2005 at 10:20 h (local summer time = UTC − 8).

Fig. 2
Fig. 2

(Color online) A, Locations of forest fires (red spots) in the vicinity of Fairbanks on 17 August 2005 at 15:00 h (local summer time = UTC − 8) displayed on the geographical map of interior Alaska. Data from the MODIS Active Fire Detection (http://activefiremaps.fs.fed.us). Yellow: previously (since 1 January 2005) burned areas. Orange: actively burning areas (last 24 h). Red: actively burning areas (last 12 h). B, C, Satellite photographs of a forest fire in the vicinity of Fairbanks [Google—Imagery © 2005 Digital Globe (http://maps.google.com)].

Fig. 3
Fig. 3

(Color online) A, Color photograph, C–E, patterns of the degree of linear polarization p, and F–H, angle of polarization α of the reddish smoky sky above Fairbanks (64° 49′ N, 147° 45′ W) measured by full-sky imaging polarimetry in the C, F, red, D, G, green, and E, H, blue parts of the spectrum on 17 August 2005 at 15:01 h (local summer time = UTC − 8). B, Theoretical α pattern of the clear sky calculated on the basis of the model of Berry et al.[21] for the same Sun position as in photograph A. The position of the Brewster neutral point is shown by br. In patterns C–H the estimated positions of the Arago and Babinet neutral points are shown by ar and ba, respectively. The optical axis of the fish-eye lens was vertical; thus the horizon and zenith are the perimeter and the center of the circular patterns, respectively. The position of the Sun is represented by a white dot. The underexposed trees near the horizon are marked by a checkered pattern.

Fig. 4
Fig. 4

(Color online) As in Fig. 3 for 20:20 h (= UTC − 8). The position of the invisible Sun occluded by the thick smoke layer near the horizon is represented by a white dot. The solar position was obtained from the online solar position calculator of the U.S. Naval Observatory, Astromonical Applications Department (http://aa.usno.navy.mil) on the basis of the exact time and geographical coordinates of the site of measurements.

Fig. 5
Fig. 5

(Color online) As Fig. 3 for a clear blue sky above the arctic ice cover measured on 25 August 2005 at 21:20 h (= UTC − 8) at the site 78° 28′ N and 149° 9′ W. The position of the Sun visible by the naked eye is represented by a yellow dot. The overexposed sky region around the Sun and the underexposed contour of the icebreaker Oden are marked by a checkered pattern.

Tables (1)

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Table 1 Optical Characteristics of the Anomalous Reddish Smoky Sky above Fairbanks a

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