Anatomy of a Wild­fire

Popular Science - - FEATURES -

The 2011 Las Con­chas wild­fire was big even be­fore it blew up on June 27.

A) A Gi­ant Rises

Ex­treme heat lofts smoke, ash, and fire into the at­mos­phere, forg­ing a 45,000-foot-tall con­vec­tive col­umn that gen­er­ates two coun­ter­ro­tat­ing vor­texes—like a gi­ant egg beater.

B) A Py­rocu­mu­lus Cloud

Burn­ing veg­e­ta­tion re­leases mois­ture, which the fire’s heat drives up the plume. It con­denses into a py­rocu­mu­lus cloud, which in turn can cre­ate ex­treme down­draft­ing winds that can fur­ther stoke the ground fire.

C) Fire­na­dos

As veg­e­ta­tion com­busts, it re­leases fuel-rich hy­dro­car­bons. Driven by up­drafts, they rise and can ig­nite into tow­ers of swirling flame.

D) Flam­ing Pine Cones

The mas­sive ver­ti­cal winds inside the col­umn can rip a pine cone off a branch, set it on fire, shoot it a few hun­dred feet into the air, then spit it as far as 2 miles away, where it can start a new fire.

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