The weather data is there; how do we respond

While we adjust for the reality of longer-term global climate change, there are still local and seasonal weather patterns that shouldn’t be ignored.

The good news is that we have a lot more detailed information than in the past. The bad news is the same. We need to know what to do with all these data or, as Peter Hayman puts it, ‘we have to ask intelligent questions’.

The Principal Scientist in Climate Applications at the South Australian Research and Development Institute* (SARDI), Dr Hayman is leading a component of a Wine Australia-funded research program designed to help the wine sector interpret and respond to what’s going on.

‘Take the seasonal drivers like El Niño, La Niña or the Indian Ocean Dipoles; a lot of people are aware of them but what do they actually mean out in the regions?’ he said. ‘Does an El Niño year mean anything for temperature or rainfall in the Barossa? Is the impact in spring or summer? We are simply asking the questions. There have been about 24 El Niños in the last 100 years, what has been the climate in those years?’

The research is being carried out at a number of levels. The most practical is the development of crop calendars, similar to those used in integrated pest management (IPM) programs, that try to link weather information to what’s happening in the vineyard. However, unlike with IPMs, where a pathologist is trying to explain something specific and date-sensitive, these crop calendars are more about trying to get a two-way flow of information between viticulturists and climate scientists.

‘The intent isn’t to try to tell viticulturists that frost matters at this time or that. The purpose is to organise the information so that we can then ask questions about where they get their information and warnings and how they respond. How do they prioritise risks?’

- Dr Peter Hayman, Principal Scientist in Climate Applications at SARDI

At a more theoretical level, the researchers are taking Australia’s long-term weather records and looking at how risk has changed in different years. ‘For example, the early indications, and what we know from other work, are that probably spring is a major time when these influences occur’, he said. ‘So, in an El Niño year we would expect more frost, probably higher day temperatures and lower night temperatures, and certainly there’s concern about winter-spring drought. The chance of that is greater in El Niño years in most wine regions in eastern and southern Australia.’

‘For example, the early indications, and what we know from other work, are that probably spring is a major time when these influences occur’, he said. ‘So, in an El Niño year we would expect more frost, probably higher day temperatures and lower night temperatures, and certainly there’s concern about winter-spring drought. The chance of that is greater in El Niño years in most wine regions in eastern and southern Australia.’

What interests Dr Hayman is how viticulturists will use this information, what decisions are negotiable, and how they might respond if they take action that proves to be counter-productive because the forecast weather patterns don’t eventuate.

‘With an annual crop, there are a whole lot of things you can do differently from year to year, but with viticulture you’re committed to so many things; you can’t just say “it’s going to be a hot summer, so let’s change our row orientation”. But there are things you can plan for if you appreciate your ability and the need to do so.’

The SARDI project, which focuses on seasonal changes, is one part of a suite of current research designed to better equip the wine sector to respond to more variable weather patterns.

A Wine Australia-funded project coordinated by the Antarctic Climate Ecosystems CRC at the University of Tasmania is focusing on the big picture of climate change, the CSIRO is looking at the impact of decadal variability, and a new national project being run by the Bureau of Meteorology is looking at how to respond to extreme conditions at the multi-week level.

Wine Australia has provided funding to this initiative to ensure that the results and operational products are beneficial to viticulture.

* SARDI is a division of Primary Industries and Regions SA (PIRSA).