Modelling

A key objective of PICCAASO is to facilitate greater collaboration between campaigns and modelling studies (see Research Priority number 6 in Mallet et al. 2023). 

Our climate models are getting more and more complex, with many CMIP6 models now including aerosol processes for the first time. This development is especially important for the Southern Ocean and Antarctic where significant cloud and radiation biases remain (see figure). 

Fig: The mean austral summer time bias in the amount of sunlight reaching the surface (incoming shortwave radiation) in Coupled Model Intercomparison Project phase 6 (CMIP6) models which fall into the “hot”, “likely” or “cold” range of equilibrium climate sensitivity with respect to the CERES-EBAF satellite product (W m-2). (See Mallet et al. 2023 for methods)

An historic lack of observations has contributed to this model bias, from conceptual models through to regional and global climate models. We know that the Southern Ocean and Antarctic region is unique to our planet and that this is not well reflected in our models. With increased modelling capability comes the need for thorough model evaluation, which depends on high-quality observations. 

This requires early conversation between campaign leaders and modellers, preferentially starting with observational design, to ensure: 

  • The fields of interest (including specifics of units and resolution in time and space) required by modellers are considered for campaigns 
  • The planned period and location of field work targets gaps in understanding for both modellers and observationalists
  • That observations are processed in a way that is useful for model evaluation (eg. quality controlled, documented and publicly available in a readable format and timely manner). 

We also highlight the need for extensive observations in both time and space, requiring collaboration across campaigns to ensure datasets are comparable and complimentary. This is a key objective of PICCAASO. 

Purposely designed modelling studies are required to evaluate and develop our models, including global simulations and regional studies. Our models also provide an important avenue for process understanding and experimental sensitivity testing. Such simulations can be expensive in both compute time and storage. We want to ensure we make the best use of our resources (both modelled and observed). 

Below we invite modelling groups to indicate their willingness to collaborate with upcoming campaigns, provide details of their previous work or upcoming projects. Please contact Sonya (sonya.fiddes@utas.edu.au) if you would like to add your projects. 

Project/Group ModelPapers/ProjectsContact
Australian Antarctic Program Partnership – Atmosphere working groupAustralian Community Climate and Earth System Simulator (ACCESS)

UM Regional Nesting Suite
Fiddes et al. (2022) 
Pei et al. (2023) 
– CN/CCN evaluation and sensitivity testing of ACCESS (in progress – looking for observations)
sonya.fiddes@utas.edu.au 
Misc. Southern Ocean studiesCESMcmcclus@ucar.edu