What You May Not Notice On Satellite

Most people are probably quite familiar with seeing satellite images like the one below that shows thunderstorms over Lake Superior and high cloudiness over Nebraska and South Dakota and the lack of cloudiness over the rest of the region.

IR satellite image

What you may not realize is that this satellite image is not actually taking a picture of clouds, but is actually measuring the temperature being emmitted from the earth over a given point. Clouds are high up in the atmosphere and are therefore colder and show up quite nicely in this type of satellite image, which is known as an infrared satellite image. What you may not notice on the satellite image is a lake breeze enhanced cold front is also visible over Wisconsin and Minnesota.

Let's take a look at the exact same satellite image, but this time, let's change the color scale to help make some interesting features show up a bit more clearly.

 infrared satellite image

If you compare the two images above, you'll notice the similarities, however you're also notice a lot more "features" showing up across Wisconsin, Illinois, and Minnesota. The image with the special color enhancement shows the lake breeze enhanced front very nicely stretching east to west across Minnesota and then southeastward across northwest into east central Wisconsin. The image also shows the pool of cold air that is sitting over top Lake Michigan where water temperatures over the middle of the lake are still in the 30s! Another interesting feature that shows up is the urban heat island effect over the Chicago metropolitan area and even up north over Milwaukee. Temperatures this morning ranged from the middle 60s downtown Chicago to the lower to middle 50s in the far outlying areas of northern Illinois. This rather subtle contrast actually shows up in satellite imagery!

 infrared satellite image



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