Pearlescent brown is a brownish sunset associated with pearl clouds that appears at dusk in the morning and evening when the Sun is below the horizon.
It is usually remarkably powerful and makes the landscape bathe in red or purple light. Most often, some degree of pearlescent is observed in the context of pearl clouds. Pearl brown can also be the dominant element in which the actual pearl clouds stand out poorly if at all.
The pearl clouds themselves are reported in the Sky Watch in the categories of colorless light (type I) and spectral color (type II) clouds.
Parel clouds are often also associated with the Bishop ring. The Bishop’s ring may be a clear sign of pearls when the Sun is on the horizon. In addition, pearlescent cloud fibers are visible, which, however, are often very inconspicuous when the Sun is on the horizon.
The Pearl Bishop gradually turns into a pearl brown in the evening as the sun continues to sink below the horizon. In the morning the opposite. However, the Bishop ring is not always visible, even if pearl clouds are observed in the morning or evening. In this case, the pearlescent brown would also appear to be weak or non-existent.
Sunset colors with pearl clouds Eetu Saarti.
Close up of mother of pearl brown. It also shows type I pale pearl clouds. Photo by Mika Aho.
Pearlescent sunset by Veikko Mäkelä.