Specular reflection from nearly horizontal ice crystals in EPIC data
Abstract
Every hour or two, the EPIC instrument onboard the DSCOVR satellite provides unique full-color images of the sunlit side of the Earth. Casual glances at such images often reveal bright and colorful spots that stand out markedly from their surroundings. These spots are quite visible not only over ocean but also over land. A closer look at these bright features over land often reveals a shape resembling a flying bird. The presented study characterizes these over land "birds" in terms of location, size, color, and brightness, and provides insights into the factors that lead to their appearance. The analysis of a yearlong dataset of EPIC images indicates that these "birds" can span over dozens of kilometers, vary in color from blue to yellow and red, and often appear in pairs or small flocks. Tracking them using an automated image analysis algorithm reveals a seasonal north-south "migration" spanning vast regions of Africa, Asia, Australia, and the Americas. A detailed analysis reveals that most "birds" are caused by specular reflection of sunlight from clouds containing nearly horizontally oriented ice crystals.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.A23D0258V
- Keywords:
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- 0321 Cloud/radiation interaction;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 3311 Clouds and aerosols;
- ATMOSPHERIC PROCESSESDE: 3359 Radiative processes;
- ATMOSPHERIC PROCESSESDE: 3360 Remote sensing;
- ATMOSPHERIC PROCESSES