Experiment Proposal: Understanding the role of the atmosphere in the triple La Nina of 2020-2022

Experiment title: Understanding the role of atmosphere in the development and predictability of the triple La Nina of 2020-2022

Tool: ACCESS-S2 coupled forecast system

Scientific justification:
There have been studies proposing that the Australian Black Summer bushfire smoke drove the development of the 2020 La Nina and preliminary reports that the Hunga-Tonga volcanic eruption contributed to the development of the 2022 La Nina.

How model design will address scientific justification:
Forecast sensitivity experiments using the ACCESS-S2 seasonal forecast system with observed ocean initial conditions but with random atmospheric initial conditions will shed some light on the role of the atmosphere that included the effects of Australian bushfire smoke and the Hunga-Tonga volcanic eruption in the development of the triple La Nina and its predictability.


Model: ACCESS-S2
Initial conditions: observed ocean initial conditions of 2020-2022 + observed atmospheric initial conditions of other random years excluding 2020-2022
Run plan: X members of 5 month forecast integration for 36 months initialised on the 1st of each month from 2020-2022
Total KSUs required for 1 member: ~250 KSU
Time required:
Total storage required for 1 member: 1.4TB

This experiment has been proposed to be a joint project with the Forecast and prediction working group. Thus, any computing/storage resources will be shared between the two working groups.


Hi @eunpalim.

Could you edit your post to include some details about the resources required for this experiment?

The example experiment proposal shows an example of the sort of information that it useful to provide

Note you don’t have to provide it in exactly that format, or exactly the same information, but it is meant to be indicative of the sort of information that would be good to provide.

At the very least we would need to know how many KSUs it would require.


Yes, Aidan
I will find out the computing resources required and post here.

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That is a great idea. From my CM2 experiment, we don’t have triple La Nina, although our ENSO period is two-three years. That will be great to check UM 8.3 and investigate what can contribute to the genesis of the triple La Nina.

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@FPWG Note this joint experiment between the Earth System Working Group and our Forecasting and Prediction Working Group.