Thunderstorms generated by a group of giant wildfires in 2017 injected a small volcano’s worth of aerosol into the stratosphere, creating a smoke plume that lasted for almost nine months. CIRES and NOAA researchers studying the plume found that black carbon or soot in the smoke was key to the plume’s rapid rise: the soot absorbed solar radiation, heating the surrounding air and allowing the plume to quickly rise.
The billowing smoke clouds provided researchers with an ideal opportunity to test climate models that estimate how long the particulate cloud would persist—after achieving a maximum altitude of 23 km, the smoke plume remained in the stratosphere for many months. These models are also important in understanding the climate effects of nuclear war or geoengineering.
“We compared observations with model calculations of the smoke plume. That helped us understand why the smoke plume rose so high and persisted so long, which can be applied to other stratospheric aerosol injections, such as from volcanoes or nuclear explosions,” said NOAA scientist Karen Rosenlof, a member of the author team that also included scientists from CU Boulder, Naval Research, Rutgers and other institutions. The findings were published today in the journal Science.
During the summer of 2017, wildfires raged across the Pacific Northwest. On August 12 in British Columbia, a group of fires and ideal weather conditions produced five near-simultaneous towering clouds of smoke or pyrocumulonimbus clouds that lofted smoke high into the stratosphere. Within two months, the plume rose from its initial height of about 12 km up to 23 km and persisted in the atmosphere for much longer—satellites could spot it even after eight months.
Read more at University of Colorado at Boulder
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