Significant Effective Radiative Forcing of Stratospheric Wildfire Smoke

The radiative forcing (RF) of volcanic sulfate is well quantified. However, the RF of pyrocumulonimbus (pyroCb) smoke with absorbing carbonaceous aerosols has not been considered in climate assessment reports. With the Community Earth System Model, we studied two record‐breaking wildfire events, the 2017 Pacific Northwest Event (PNE) and the 2019–2020 Australian New Year event (ANY), that perturbed stratospheric chemistry and the earth's radiation budget. We calculated a global annual‐mean effective RF (ERF) of −0.04 ± 0.02 and −0.17 ± 0.02 W/m2 at the top of the atmosphere (TOA) for PNE and ANY, respectively. The complexity of longwave RF led to an uncertainty of about 50% in the ERF at the TOA among climate models. We found that modeled ERF from wildfire smoke was 70%–270% more negative than the ERF of mass‐equivalent sulfate aerosol, highlighting its important role in the climate radiative budget.

[1]  B. Legras,et al.  Radiative impacts of the Australian bushfires 2019–2020 – Part 1: Large-scale radiative forcing , 2022, Atmospheric Chemistry and Physics.

[2]  M. Dubey,et al.  Contrasting Stratospheric Smoke Mass and Lifetime From 2017 Canadian and 2019/2020 Australian Megafires: Global Simulations and Satellite Observations , 2022, Journal of Geophysical Research: Atmospheres.

[3]  P. Bernath,et al.  Wildfire smoke destroys stratospheric ozone , 2022, Science.

[4]  S. Solomon,et al.  On the stratospheric chemistry of midlatitude wildfire smoke , 2022, Proceedings of the National Academy of Sciences of the United States of America.

[5]  E. Ray,et al.  Dominant role of mineral dust in cirrus cloud formation revealed by global-scale measurements , 2022, Nature Geoscience.

[6]  L. Froidevaux,et al.  Prolonged and Pervasive Perturbations in the Composition of the Southern Hemisphere Midlatitude Lower Stratosphere From the Australian New Year's Fires , 2022, Geophysical Research Letters.

[7]  J. Dykema,et al.  Composition Dependence of Stratospheric Aerosol Shortwave Radiative Forcing in Northern Midlatitudes , 2021, Geophysical Research Letters.

[8]  S. Solomon,et al.  Stratospheric Temperature and Ozone Anomalies Associated With the 2020 Australian New Year Fires , 2021, Geophysical Research Letters.

[9]  A. Steiner,et al.  Observing the climate impact of large wildfires on stratospheric temperature , 2021, Scientific Reports.

[10]  L. Oman,et al.  The long-term transport and radiative impacts of the 2017 British Columbia pyrocumulonimbus smoke aerosols in the stratosphere , 2021, Atmospheric Chemistry and Physics.

[11]  M. Fromm,et al.  Australia’s Black Summer pyrocumulonimbus super outbreak reveals potential for increasingly extreme stratospheric smoke events , 2021, npj Climate and Atmospheric Science.

[12]  K. Rosenlof,et al.  Persistent Stratospheric Warming Due to 2019–2020 Australian Wildfire Smoke , 2021, Geophysical Research Letters.

[13]  I. Koren,et al.  Record-breaking aerosol levels explained by smoke injection into the stratosphere , 2021, Science.

[14]  L. Thomason,et al.  Evaluation of a method for converting Stratospheric Aerosol and Gas Experiment (SAGE) extinction coefficients to backscatter coefficients for intercomparison with lidar observations , 2020 .

[15]  M. Fromm,et al.  Australian PyroCb Smoke Generates Synoptic‐Scale Stratospheric Anticyclones , 2020, Geophysical Research Letters.

[16]  B. Legras,et al.  The 2019/20 Australian wildfires generated a persistent smoke-charged vortex rising up to 35 km altitude , 2020, Communications Earth & Environment.

[17]  J. Mülmenstädt,et al.  Bounding Global Aerosol Radiative Forcing of Climate Change , 2020, Reviews of geophysics.

[18]  N. Krotkov,et al.  Stratospheric Injection of Massive Smoke Plume From Canadian Boreal Fires in 2017 as Seen by DSCOVR‐EPIC, CALIOP, and OMPS‐LP Observations , 2018, Journal of Geophysical Research: Atmospheres.

[19]  Matthew J. McGill,et al.  Radiative Forcing and Stratospheric Warming of Pyrocumulonimbus Smoke Aerosols: First Modeling Results With Multisensor (EPIC, CALIPSO, and CATS) Views from Space , 2019, Geophysical Research Letters.

[20]  J. D. de Gouw,et al.  Black carbon lofts wildfire smoke high into the stratosphere to form a persistent plume , 2019, Science.

[21]  J. Evans,et al.  Climate Change Increases the Potential for Extreme Wildfires , 2019, Geophysical Research Letters.

[22]  M. J. Costa,et al.  The unprecedented 2017–2018 stratospheric smoke event: Decay phase and aerosol properties observed with EARLINET , 2019 .

[23]  S. Freitas,et al.  Efficient In‐Cloud Removal of Aerosols by Deep Convection , 2019, Geophysical research letters.

[24]  P. Bhartia,et al.  Evaluation of OMPS/LP Stratospheric Aerosol Extinction Product Using SAGE III/ISS Observations , 2019 .

[25]  J. Jimenez,et al.  A new method to quantify mineral dust and other aerosol species from aircraft platforms using single particle mass spectrometry , 2019 .

[26]  Qiaoqiao Wang,et al.  Strong impact of wildfires on the abundance and aging of black carbon in the lowermost stratosphere , 2018, Proceedings of the National Academy of Sciences.

[27]  Andrew Gettelman,et al.  Volcanic Radiative Forcing From 1979 to 2015 , 2018, Journal of Geophysical Research: Atmospheres.

[28]  T. Andrews,et al.  Understanding Rapid Adjustments to Diverse Forcing Agents , 2018, Geophysical research letters.

[29]  M. Fromm,et al.  Wildfire-driven thunderstorms cause a volcano-like stratospheric injection of smoke , 2018, npj Climate and Atmospheric Science.

[30]  R. Engelmann,et al.  Extreme levels of Canadian wildfire smoke in the stratosphere over central Europe on 21–22 August 2017 , 2018, Atmospheric Chemistry and Physics.

[31]  J. Pelon,et al.  Stratospheric Smoke With Unprecedentedly High Backscatter Observed by Lidars Above Southern France , 2018 .

[32]  Philippe Xu,et al.  The Ozone Mapping and Profiler Suite (OMPS) Limb Profiler (LP) Version 1 aerosol extinction retrieval algorithm: theoretical basis , 2017 .

[33]  C. Timmreck,et al.  Stratospheric aerosol—Observations, processes, and impact on climate , 2016 .

[34]  A. Schmidt,et al.  Global volcanic aerosol properties derived from emissions, 1990–2014, using CESM1(WACCM) , 2016 .

[35]  R. Portmann,et al.  A Temporal Kernel Method to Compute Effective Radiative Forcing in CMIP5 Transient Simulations , 2016 .

[36]  J. Vernier,et al.  Significant radiative impact of volcanic aerosol in the lowermost stratosphere , 2015, Nature Communications.

[37]  J. M. English,et al.  Evaluations of tropospheric aerosol properties simulated by the community earth system model with a sectional aerosol microphysics scheme , 2015, Journal of advances in modeling earth systems.

[38]  M Höpfner,et al.  Stratospheric sulfur and its implications for radiative forcing simulated by the chemistry climate model EMAC , 2015, Journal of geophysical research. Atmospheres : JGR.

[39]  Makiko Sato,et al.  Total volcanic stratospheric aerosol optical depths and implications for global climate change , 2014 .

[40]  M. Dubey,et al.  Brownness of organics in aerosols from biomass burning linked to their black carbon content , 2014 .

[41]  Gavin A. Schmidt,et al.  Reconciling warming trends , 2014 .

[42]  Richard Neale,et al.  Toward a Minimal Representation of Aerosols in Climate Models: Description and Evaluation in the Community Atmosphere Model CAM5 , 2012 .

[43]  J. Lamarque,et al.  CAM-chem: description and evaluation of interactive atmospheric chemistry in the Community Earth System Model , 2012 .

[44]  A. T. J. de Laat,et al.  A solar escalator: Observational evidence of the self‐lifting of smoke and aerosols by absorption of solar radiation in the February 2009 Australian Black Saturday plume , 2012 .

[45]  K. Caldeira,et al.  Dependence of climate forcing and response on the altitude of black carbon aerosols , 2012, Climate Dynamics.

[46]  R. Neely,et al.  The Persistently Variable “Background” Stratospheric Aerosol Layer and Global Climate Change , 2011, Science.

[47]  Thomas Trickl,et al.  The Untold Story of Pyrocumulonimbus , 2010 .

[48]  T. Deshler.  A review of global stratospheric aerosol: Measurements, importance, life cycle, and local stratospheric aerosol , 2008 .

[49]  James J. Hack,et al.  A New Sea Surface Temperature and Sea Ice Boundary Dataset for the Community Atmosphere Model , 2008 .

[50]  W. Collins,et al.  Radiative forcing by long‐lived greenhouse gases: Calculations with the AER radiative transfer models , 2008 .

[51]  T. Bond,et al.  Light Absorption by Carbonaceous Particles: An Investigative Review , 2006 .

[52]  Jay R. Herman,et al.  Correction to “Pyro‐cumulonimbus injection of smoke to the stratosphere: Observations and impact of a super blowup in northwestern Canada on 3–4 August 1998” , 2005 .

[53]  Jay R. Herman,et al.  Pyro-cumulonimbus injection of smoke to the stratosphere: Observations and impact of a super blowup in northwestern Canada , 2005 .

[54]  P. Koepke,et al.  Optical Properties of Aerosols and Clouds: The Software Package OPAC , 1998 .

[55]  E. Mlawer,et al.  Radiative transfer for inhomogeneous atmospheres: RRTM, a validated correlated-k model for the longwave , 1997 .

[56]  T. Trickl,et al.  35 yr of stratospheric aerosol measurements at Garmisch-Partenkirchen : from Fuego to Eyjafjallaj ökull , and beyond , 2022 .