The Suomi NPP satellite's VIIRs instrument captured this view of clear skies over the mouth of the St. Lawrence River on January 22, 2018. Clouds often obscure the Canadian maritime provinces during the winter months, due to storm systems and the temperature contrast between cold land areas and the relatively warmer river and sea waters. This image shows the snow-covered land of eastern Canada in stunning detail. Ice floes can be discerned in the bluish-gray areas extending from the river shoreline. The ring-shaped Manicouagan Reservoir, site of one of the world's oldest impact craters, can be seen in the upper left. Low tide in the Bay of Fundy, home to the world's most extreme tidal swings, is also evident in the brown areas at the bottom-center portion of this imagery.
Connecting the Great Lakes to the Atlantic Ocean, the St. Lawrence River is one of the longest rivers in North America and the primary waterway serving eastern Canada. The stretch of river between Quebec City and the Gulf of St. Lawrence (shown in the left half of this image) forms the largest river estuary in the world.
Although true-color images like this may appear to be photographs of Earth, they aren't. They are created by combining data from the three color channels on the VIIRS instrument sensitive to the red, green and blue (or RGB) wavelengths of light into one composite image. In addition, data from several other channels are often also included to cancel out or correct atmospheric interference that may blur parts of the image.