Forest corona & simulator test
Image Index      Forest corona captured by Till Credner and Sven Kohle (atmospheric optics site) on the island of Tenerife in May 2000. Fragments of three to four rings are visible above the aureole and to add to the spectacle, crepuscular rays fan in all directions. The corona forming droplets are close because the rings shine in front of the nearby trees. Photo ©Till Credner & Sven Kohle and reproduced with permission.                    IRIS simulator test In the opposite direction there was a glory. The droplets creating both were likely of the same size and thus the two sightings provide a test of the IRIS Mie scattering simulator. In the split image the angular scale (major ticks 1°) were gauged from the camera lens focal length. The IRIS corona best fitting the image was from 13.5 micron diameter droplets.  The rings rather than the aureole were used for fitting because the aureole's size in images and simulations depends too much on exposure and brightness settings. No spread of droplet sizes was needed, monodisperse droplets best matched the image. Did the same sized droplets fit the glory seen at the same time? Yes they did, check the glory image.

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