Parallel Session 2: Alanah Chapman: A model sensitivity analysis of aerosol precursor emissions related to sea-ice processes

ACCESS Workshop 2025 ACCESS Workshop Day 1
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A model sensitivity analysis of aerosol precursor emissions related to sea-ice processes

Alanah Chapman


Alanah Chapman (University of Melbourne), Matt Woodhouse (CSIRO Aspendale), Sonya Fiddes (AAPP, UTAS), Yi Huang (University of Melbourne), Robyn Schofield (University of Melbourne)

  1. Aerosol and their complex interactions with clouds and radiation – particularly over the Southern Ocean – remains a large source of uncertainty within climate model estimates of global radiative forcing. The largest model biases in the Australian Community Climate and Earth-System Simulator Atmosphere Model v2 (ACCESS-AM2) are found over the sea-ice melt period during late spring-early summer, over the high latitudes.
  2. We investigate dimethyl sulfide (DMS) precursor aerosol emissions related to sea-ice processes on modelled aerosol and cloud properties by conducting a model sensitivity analysis. The sensitivity analysis uses ACCESS-AM2 which has a two-moment aerosol scheme, GLOMAP-mode, with resolved aerosol mass and number.
  3. Experiments with twice, four and eight times the estimated yearly DMS flux from observations are conducted over the Antarctic polar region. Additional DMS emissions are focused on spatial and temporal periods where sea-ice melt occurs, a possible missing aerosol source.
  4. Climate, atmospheric and polar scientists
  5. ACCESS-AM2, aerosol, DMS, Southern Ocean, sea-ice, model radiation bias, aerosol-cloud interactions, CCN


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