A message from the Director

Dr Wenju Cai (Image source: Alex Drewniak)

The fourth year of CSHOR operation has come to a close. The significant research reported by our six projects confirms that we are on our way to discovering more about the southern hemisphere oceans from the tropics to the Antarctic.

The Centre produced six high profile research articles for the Nature group. In total, there were 45 journal articles, four book chapters, and one book (CSHOR staff contributing as editors).

We were able to take advantage of the fast development of high-resolution models in the assessment of the Southern Ocean warming rate, increased marine heatwaves, intensifying oceanic eddies in a warming climate, and in quantifying mixing in the Indonesian Throughflow passage. The latter is an order of magnitude above background level because of converging energy that enters the Indonesian Seas.

CSHOR has begun to harvest results from the investment in observations over the previous years. Our deployment of Deep Argo floats near Antarctica is revealing spreading paths, interactions, and variability of two sources of Antarctic Bottom Water. In just two years, the floats have increased the number of winter profiles by a factor of 5, enabling much needed understanding of variability and change, including off East Antarctica, where the ice sheet is losing mass.

Further, using observations and models, CSHOR scientists show that concurrence of two-year consecutive positive Indian Ocean Dipole (IOD) events and two-year-consecutive central Pacific El Niño events during 2018-2019 conspired to induce droughts that precondition the 2019-20 Australian Black Summer bushfires, and that prediction of the impact from El Niño and the IOD would benefit from memory of sea-surface salinity and soil moisture as shown in a deep machine learning framework.

Using outputs of the latest climate models from around the world, our scientists have shown that the Intergovernmental Panel on Climate Change (IPCC) sea level projections are consistent with observations in terms of both trend and acceleration, have assessed the likelihood of extreme sea level increase, and have made advances in assessing uncertainty sources of the projected changes. The results reveal a future El Niño frequency increase if past internal variability is lower, and an opposite response of extreme positive IOD, which will increase under greenhouse warming, to that of moderate positive IOD, which is projected to decrease. The scientific outcomes will contribute to our further success in the fifth year of CSHOR.

Further detail is available in the CSHOR 2020-21 Annual Report.

Kind regards,

 

 

Dr Wenju Cai FAA, CSHOR Director

August 2021