Ulli Seibt

Upcoming Seminar

(270 Seminar) The Unprecedented Pyrocumulonimbus Super Outbreak in Australia at the Dawn of 2020: Cause and Perspective

Wed, Apr 21, 2021

Zoom Seminar

Speaker: David A. Peterson

Institution: United States Naval Research Laboratory Monterey, CA

Abstract:

The Black Summer fire season of 2019-2020 in southeastern Australia contributed to an unprecedented “super outbreak” of fire-induced and smoke-infused thunderstorms, known as pyrocumulonimbus (pyroCb). More than half of the 38 observed pyroCbs injected smoke particles directly into the stratosphere, producing two of the three largest smoke plumes observed at such altitudes to date. Over the course of three months, these plumes encircled a large swath of the Southern Hemisphere while continuing to rise, in a manner consistent with existing nuclear winter theory. We connect cause and effect of this event by quantifying the fire characteristics, fuel consumption, and meteorology contributing to the pyroCb spatiotemporal evolution. Emphasis is placed on the unusually long duration of sustained pyroCb activity and anomalous persistence during nighttime hours. The ensuing stratospheric smoke plumes are compared with plumes injected by significant volcanic eruptions over the last decade. As the second record-setting stratospheric pyroCb event in the last four years, the Australian super outbreak offers new clues on the potential scale and intensity of this increasingly extreme fire-weather phenomenon in a warming climate.

Ulli Seibt

Specialty: Terrestrial biogeochemistry, biosphere-atmosphere interactions

Notes: Diploma, Max Planck Institute for Meteorology, Hamburg,
and University of Tübingen, Germany
Ph.D., Max Planck Institute for Biogeochemistry, Jena,
and University of Hamburg, Germany

ulli [at] atmos.ucla.edu

Associate Professor

MSA 7975

https://sites.google.com/site/useibt/

Atmospheric and Oceanic Sciences

55°

Fog

Campus Address

Mailing Address

Contact Information

Campus Address	Mailing Address	Contact Information
520 Portola Plaza	UCLA Atmospheric & Oceanic Sciences	Students Services Office: (310) 825-1954
Math Sciences Building 7127	Box 951565	Email: studentinfo@atmos.ucla.edu
Los Angeles, CA 90095	Los Angeles, CA 90095-1565	Phone: (310) 825-1217