Iridescent Moon ring

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Often we can see an iridescent crown (ring or halo) around the Moon. From time immemorial, this phenomenon is related to the culture of many nations, a harbinger of cold, rain or snow. But often the beauty of nature is short and portends bad weather.

Fig.1. Iridescent crown around the Moon (06 Nov 2011).

Human dependence on the vagaries of time led him to observe atmospheric phenomena, to ensure their consistency and trying to predict changes. These experiences of generation’s people have understood that various changes in time are preceded by specific phenomena or events. As a result different cultures have developed folk or local signs of weather prediction. Now most of phenomena can be explained scientifically, but we continue to trust some beliefs that are often strikingly accurate.

The appearance of the color ring around the Moon in Bulgaria is called harman (threshing floor) - large, flat and round place to collect and process the seeds of cereals. This is called the time of threshing. This word comes in Bulgarian from Turkish word Harman Yeri


Fig. 2. Threshing floor view from Turkey and Grrece

According to tradition in Bulgaria, the emergence of harman is a harbinger of bad weather. Usually, bad weather occurs in the next 2-3 days. Iridescent clouds around the Moon are consequence from a pushed warmer air, which formed the most high and thin clouds. Diffraction of light by small water droplets (or small ice crystals) forming the clouds is the physical explanation for the moon-colored crown. The radius of this Moon wreath is from 1 to 8 arc degrees. Moons threshing floor is not the same as a rare phenomenon observed 22o Moon halo.


Fig. 3. Threshing floor images from 06 Nov 2011. Using CANON 1Ds Mark II, lenses 200mm f/2.8 (left) and lenses 20mm SIGMA f/1.8 (right).

Beautiful, colored in yellow, orange or red sunrises and sunsets are likewise associated with weather condition changes in short time, as in the moon crown. Beautiful sunrises and sunsets, panoramic images from the territory of NAO Rozhen are shown below.

Fig. 4. View from window at home sunrise on 07 Nov 2011.

Fig. 5. Sunset over the Rhodope Mountains of November 6, 2011