A Phase 2 project: Simulating clouds and aerosols in the NZESM
The region between Aotearoa New Zealand and Antarctica – the Southern Ocean – plays an important role in influencing New Zealand’s weather and climate.
Because it’s so remote, the Southern Ocean’s atmosphere is considered one of the last pristine locations on the planet. Here the air is relatively clean and the dominant sources of atmospheric particulate matter (“aerosols”) are sea spray and phytoplankton activity.
The Southern Ocean is also one of the cloudiest regions on the planet, which presents unique challenges to climate modellers. The 5th IPCC Assessment Report (published in 2013) confirmed that clouds and aerosols are still a leading source of errors in global climate models. These errors are particularly prevalent over the Southern Ocean, where they cascade to errors in simulated sea surface temperature, the position of the storm track, rainfall and extreme weather events in New Zealand.
This project aims to improve the representation of clouds and aerosols over the Southern Ocean in New Zealand’s own climate model, the NZ Earth System Model (NZESM), with the overarching goal of improving climate change projections for Aotearoa New Zealand. It builds on the Phase 1 projects Clouds & Aerosols and Sulfate aerosols over the Southern Ocean. These projects conducted a variety of relevant observations in the Southern Ocean, helped establish the NZESM and built capacity in microphysics and aerosol research among the Deep South Challenge community.