Monday, September 26, 2016
Thermal Image of the Northeast (9/29)
This image was taken on September 13th by the VIIRS instrument on one of NOAA's satellites. It senses thermal radiation to show variations in temperature across Earth's surface. In this photo of the northeast coast of the US, blue tones signify cooler surface temperatures and yellow tones signify warmer temperatures. It is interesting to see the temperature change between ocean currents, the difference in temperature between ocean and land, and the pockets of heat in densely populated areas. You can also detect lots of relief detail, with valleys being slightly warmer than mountains. Whatever processing was done to assign temperature ranges to different colors really helped create a striking and easily comprehensible image.
The ability to sense thermal radiation is really useful because it helps us visualize phenomena otherwise invisible to us. We can use it to track pollution plumes, land cover change, seasonal changes in a landscape, effects of urbanization, etc.