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Important role of stratospheric injection height for the distribution and radiative forcing of smoke aerosol from the 2019–2020 Australian wildfires

Journal Article · · Atmospheric Chemistry and Physics (Online)
More than 1 Tg smoke aerosol was emitted into the atmosphere by the exceptional 2019–2020 southeastern Australian wildfires. Triggered by the extreme fire heat, several deep pyroconvective events carried the smoke directly into the stratosphere. Once there, smoke aerosol remained airborne considerably longer than in lower atmospheric layers. The thick plumes traveled eastward, thereby being distributed across the high and mid-latitudes in the Southern Hemisphere, enhancing the atmospheric opacity. Due to the increased atmospheric lifetime of the smoke plume, its radiative effect increased compared to smoke that remains in lower altitudes. Global models describing aerosol-climate impacts lack adequate descriptions of the emission height of aerosols from intense wildfires. Here, we demonstrate, by a combination of aerosol-climate modeling and lidar observations, the importance of the representation of those high-altitude fire smoke layers for estimating the atmospheric energy budget. Through observation-based input into the simulations, the Australian wildfire emissions by pyroconvection are explicitly prescribed to the lower stratosphere in different scenarios. Based on our simulations, the 2019–2020 Australian fires caused a significant top-of-atmosphere (TOA) hemispheric instantaneous direct radiative forcing signal that reached a magnitude comparable to the radiative forcing induced by anthropogenic absorbing aerosol. Up to +0.50 W m-2 instantaneous direct radiative forcing was modeled at TOA, averaged for the Southern Hemisphere (+0.25 W m-2 globally) from January to March 2020 under all-sky conditions. At the surface, on the other hand, an instantaneous solar radiative forcing of up to -0.81 W m-2 was found for clear-sky conditions, with the respective estimates depending on the model configuration and subject to the model uncertainties in the smoke optical properties. Since extreme wildfires are expected to occur more frequently in the rapidly changing climate, our findings suggest that high-altitude wildfire plumes must be adequately considered in climate projections in order to obtain reasonable estimates of atmospheric energy budget changes.
Research Organization:
Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
Sponsoring Organization:
USDOE
Grant/Contract Number:
AC05-76RL01830
OSTI ID:
1882841
Report Number(s):
PNNL-SA-167820
Journal Information:
Atmospheric Chemistry and Physics (Online), Journal Name: Atmospheric Chemistry and Physics (Online) Journal Issue: 15 Vol. 22; ISSN 1680-7324
Publisher:
Copernicus Publications, EGUCopyright Statement
Country of Publication:
United States
Language:
English

References (63)

CMIP5 simulations of the Max Planck Institute for Meteorology (MPI-M) based on the MPI-ESM-LR model: The amip4xCO2 experiment, served by ESGF dataset January 2012
Paths to accuracy for radiation parameterizations in atmospheric models: PATHS TO PARAMETERIZATION ACCURACY journal May 2013
Climate and carbon cycle changes from 1850 to 2100 in MPI-ESM simulations for the Coupled Model Intercomparison Project phase 5: Climate Changes in MPI-ESM journal July 2013
Bounding the role of black carbon in the climate system: A scientific assessment: BLACK CARBON IN THE CLIMATE SYSTEM journal June 2013
The ERA5 global reanalysis journal June 2020
Dependence of climate forcing and response on the altitude of black carbon aerosols journal April 2011
AERONET—A Federated Instrument Network and Data Archive for Aerosol Characterization journal October 1998
After the Megafires: What Next for Australian Wildlife? journal September 2020
Clouds and Aerosols book June 2014
M7: An efficient size-resolved aerosol microphysics module for large-scale aerosol transport models: AEROSOL MICROPHYSICS MODULE journal November 2004
Radiative forcing by long-lived greenhouse gases: Calculations with the AER radiative transfer models journal January 2008
Anthropogenic and natural contributions to regional trends in aerosol optical depth, 1980–2006 journal January 2009
Lifting potential of solar-heated aerosol layers: LIFTING POTENTIAL journal December 2010
Attribution of the influence of human‐induced climate change on an extreme fire season journal December 2018
On the Limits of CALIOP for Constraining Modeled Free Tropospheric Aerosol journal September 2018
Global Emergence of Anthropogenic Climate Change in Fire Weather Indices journal January 2019
Volcanic Radiative Forcing From 1979 to 2015 journal November 2018
The Primary Convective Pathway for Observed Wildfire Emissions in the Upper Troposphere and Lower Stratosphere: A Targeted Reinterpretation journal December 2019
Bounding global aerosol radiative forcing of climate change journal November 2019
Australian PyroCb Smoke Generates Synoptic‐Scale Stratospheric Anticyclones journal July 2020
Pyrocumulonimbus Stratospheric Plume Injections Measured by the ACE‐FTS journal August 2020
Detection of Aerosols in Antarctica From Long‐Range Transport of the 2009 Australian Wildfires journal December 2020
Persistent Stratospheric Warming Due to 2019–2020 Australian Wildfire Smoke journal April 2021
Climate-induced variations in global wildfire danger from 1979 to 2013 journal July 2015
Significant radiative impact of volcanic aerosol in the lowermost stratosphere journal July 2015
Biomass burning aerosols in most climate models are too absorbing journal January 2021
Unprecedented burn area of Australian mega forest fires journal February 2020
Impact of 2019–2020 mega-fires on Australian fauna habitat journal July 2020
Future changes in extreme weather and pyroconvection risk factors for Australian wildfires journal July 2019
Wildfire-driven thunderstorms cause a volcano-like stratospheric injection of smoke journal August 2018
Australia’s Black Summer pyrocumulonimbus super outbreak reveals potential for increasingly extreme stratospheric smoke events journal July 2021
The 2019/20 Australian wildfires generated a persistent smoke-charged vortex rising up to 35 km altitude journal September 2020
Prescribed burning in south-eastern Australia: history and future directions journal January 2020
Potential climate change impacts on fire intensity and key wildfire suppression thresholds in Canada journal September 2016
Key indicators of Arctic climate change: 1971–2017 journal April 2019
Fire in the Earth System journal April 2009
Record-breaking aerosol levels explained by smoke injection into the stratosphere journal March 2021
The Untold Story of Pyrocumulonimbus journal September 2010
Inversion with regularization for the retrieval of tropospheric aerosol parameters from multiwavelength lidar sounding journal January 2002
A Global Analysis of Wildfire Smoke Injection Heights Derived from Space-Based Multi-Angle Imaging journal October 2018
The global aerosol-climate model ECHAM-HAM, version 2: sensitivity to improvements in process representations journal January 2012
The global 3-D distribution of tropospheric aerosols as characterized by CALIOP journal January 2013
Fire emission heights in the climate system – Part 1: Global plume height patterns simulated by ECHAM6-HAM2 journal July 2015
Impacts of global open-fire aerosols on direct radiative, cloud and surface-albedo effects simulated with CAM5 journal January 2016
An overview of the first decade of Polly NET : an emerging network of automated Raman-polarization lidars for continuous aerosol profiling journal January 2016
A review of approaches to estimate wildfire plume injection height within large-scale atmospheric chemical transport models journal January 2016
Two global data sets of daily fire emission injection heights since 2003 journal January 2017
Depolarization and lidar ratios at 355, 532, and 1064 nm and microphysical properties of aged tropospheric and stratospheric Canadian wildfire smoke journal January 2018
The unprecedented 2017–2018 stratospheric smoke event: decay phase and aerosol properties observed with the EARLINET journal January 2019
Smoke of extreme Australian bushfires observed in the stratosphere over Punta Arenas, Chile, in January 2020: optical thickness, lidar ratios, and depolarization ratios at 355 and 532 nm journal January 2020
Hemispheric contrasts in ice formation in stratiform mixed-phase clouds: disentangling the role of aerosol and dynamics with ground-based remote sensing journal January 2021
Dilution impacts on smoke aging: evidence in Biomass Burning Observation Project (BBOP) data journal January 2021
Effective radiative forcing from emissions of reactive gases and aerosols – a multi-model comparison journal January 2021
Australian wildfire smoke in the stratosphere: the decay phase in 2020/2021 and impact on ozone depletion journal June 2022
A review of biomass burning emissions part III: intensive optical properties of biomass burning particles journal January 2005
Advancements in the Aerosol Robotic Network (AERONET) Version 3 database – automated near-real-time quality control algorithm with improved cloud screening for Sun photometer aerosol optical depth (AOD) measurements journal January 2019
Discriminating between clouds and aerosols in the CALIOP version 4.1 data products journal January 2019
The automated multiwavelength Raman polarization and water-vapor lidar PollyXT: the neXT generation journal January 2016
Biomass burning emissions estimated with a global fire assimilation system based on observed fire radiative power journal January 2012
A continued role of short-lived climate forcers under the Shared Socioeconomic Pathways journal November 2020
The global aerosol–climate model ECHAM6.3–HAM2.3 – Part 1: Aerosol evaluation journal January 2019
Data for paper publication 'Important role of stratospheric injection height for the distribution and radiative forcing of smoke aerosol from the 2019/2020 Australian wildfires' dataset January 2021
NOAA Climate Data Record (CDR) of AVHRR Daily and Monthly Aerosol Optical Thickness (AOT) over Global Oceans, Version 3.0 dataset January 2017

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