Thursday, March 11, 2021

Fires in the Western United States, 2020

Watching the planet from the various instruments that are available in orbit offers some really clear insights into just how unusual the fires of 2020 were - not just in California, but across the West, including in Oregon, Colorado, and Washington. I screen captured (from the NASA firms system) one-week integrations of all the points on the ground that registered as "on fire" in the infrared and stitched them into a short movie.

At the beginning of the year, the fires are almost all in agricultural lands of the Central Valley. Fire pixels tend to be isolated or in very small groups, representing the burning of individual or groups of fields. This is from the week spanning February 5th through 11th, 2020.

By the end of October, the fires are mostly in the wildlands, and once again are small and distributed widely. Notice the large organized fires in the Sierra Nevada Mountains just below picture center - this is the end of on of the massive fires.

Compare either of the above photos with this one from the week of September 9th through 15th, 2020 - look at the numerous large fires that are crossing the Cascades, North Coast Ranges, Sierra Nevada, and San Gabriel Mountains.


Having just one of these mesoscale fires is unusual, having a dozen or more is unprecedented. These are burning concurrently, not just in the fire prone areas of Southern California, but in the Redwood forests of the Northern California coast and completely crossing several of the largest mountain ranges in North America.

The reasons for this are numerous and complex, and the topic of my next post.