File:Slovakia (4690803639).jpg

False-color images, like this one of northern central Europe, can be hard to interpret unless you know what each color corresponds to. This particular image, from the Terra MODIS instrument, shows snow cover and clouds on the land and water. The bright turquoise and black colors correspond to ice- and snow-free land and water (respectively), while white corresponds to cloud cover, and red corresponds to snow.

As can be seen in this image, snow covers much of northern central Europe on December 9th, 2002. The snow stretches, from top to bottom, through Latvia (top right), Lithuania, a small piece of the Russian Federation (between Poland and Lithuania), western Belarus, eastern Poland, and down into the Carpathian Mountains of western Ukraine and Romania. A thinner line of snow and clouds also runs along the Poland and Czech Republic/Slovakia border.

The benefit of creating false color images is that they can show a visual difference between snow and ice, whereas in true-color images, they look very much the same and can be very hard, if not impossible, to distinguish. Clouds and snow have different temperature signatures, which make it possible to assign them different colors. Likewise, bare land and snow or cloud-covered lands have different temperature signatures. Compare this to the true-color image of the same scene, where snow and cloud can be hard to distinguish.

Credit Jeff Schmaltz, MODIS Rapid Response Team, NASA/GSFC

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