Identification

Title

Two-years of stratospheric chemistry perturbations from the 2019â€“2020 Australian wildfire smoke

Abstract

The very large pyrocumulonimbus events that occurred during the Australian summer of 2019â€“2020 caused extremely unusual partitioning of stratospheric chlorine in the Southern Hemisphere midlatitude and Antarctic regions not only in 2020 but also in 2021. This was likely caused by enhanced HCl solubility in organic species that increased heterogeneous chemistry. Here, we show that observed HCl and ClONO2 values remain outside the pre-wildfire satellite range, measured from 2005 until just prior to the event, in both the Southern Hemisphere midlatitude and Antarctic regions in 2021. Through model simulations, we replicate this prolonged multiyear chemical perturbation, in good agreement with observations. This was achieved by calculating the HCl solubility in mixed wildfire and sulfate aerosols consistent with assumptions of (1) liquidâ€“liquid phase separation and (2) linear dependence on organic and sulfate composition. The model simulations also suggest that the Australian pyrocumulonimbus organic aerosols contributed to low midlatitude ozone values in 2020 and 2021. A marked, photochemically controlled seasonality of the chemical perturbations and ozone depletion is also observed and simulated, and its underlying chemical drivers are identified. This work highlights that lower concentrations of smoke still had profound effects on stratospheric heterogeneous chemistry more than a year after the 2019â€“2020 wildfire event.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.net/ark:/85065/d7pv6qtp

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

Geographic location

West bounding longitude

East bounding longitude

North bounding latitude

South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2025-07-22T00:00:00Z

Frequency of update

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Conformity

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Use constraints

<span style="font-family:Arial;font-size:10pt;font-style:normal;font-weight:normal;" data-sheets-root="1">Copyright author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.</span>

Limitations on public access

None

Responsible organisations

Responsible party

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact