 EPOD - a service of USRA

The Earth Science Picture of the Day (EPOD) highlights the diverse processes
and phenomena which shape our planet and our lives. EPOD will collect and
archive photos, imagery, graphics, and artwork with short explanatory
captions and links exemplifying features within the Earth system. The
community is invited to contribute digital imagery, short captions and
relevant links.


 Dark Spots and Patterns on Lake Ice

   January 15, 2021

    Mm_spots01 (002)a

    Mm_spots03 (003)b

   Photographer: Mr. Moose
   Summary Author: Mr. Moose

    Patterns on Lake Ice2222222222 A few weeks back,  ice covered
   the lake near my home for the first time this season. It was quite thin
   (less than one-quarter inch or 6 mm) and completely clear and smooth
   and thus appeared rather dark since lake water was easily visible
   through it. Not until  ice thickens and gets rough does it attain
   the matte white look that most people think of when they envision ice.

   During the early afternoon I noticed that a thin layer of snow covered
   the ice and also it was now littered with a few leaves (top photo).
   Later on, there were dark spots on the ice, and at the center of each
   spot was a leaf (inset photo). Later yet, these spots had grown in size
   (bottom photo). The leaves were melting the snow and exposing the ice,
   not because they were warm but rather because  dark leaves absorb
   solar radiation more readily than does snow. This continued in a
   feedback loop where the dark spot on the ice then absorbed more
    radiation and continued to get larger and larger, even when the sky
   was overcast. Notice also the more  star-like or spider-like pattern
   of the smaller spots (bottom photo). It should be mentioned that when
   the snow or ice is thicker, I never see this phenomenon. Photos taken
   on November 21, 2020.
     * Oneida County, Wisconsin Coordinates:  45.6751, -89.4617

Related EPODs

    Dark Spots and Patterns on Lake Ice  Surface Hoar Formation
    Not all Snow Crystals are Perfectly Symmetrical  Archive - Blue
   Light From Deep Snow  Archive - Lago Grey Icebergs  Iceberg
   Lagoon
    More...

Cryosphere Links

     *  Guide to Frost
     *  What is the Cryosphere?
     *  Bentley Snow Crystals
     *  Glaciers of the World
     *  Ice, Snow, and Glaciers: The Water Cycle
     *  The National Snow and Ice Data Center Google Earth Images
     *  Snow and Ice Crystals

-
   Earth Science Picture of the Day is a service of the  Universities
   Space Research Association.

https://epod.usra.edu
 
