Gardeners throughout the world dread the words ‘El Niño’. In Australia it means a very long, dry, hot summer often resulting in severe drought conditions and catastrophic bushfires. In California it means damaging storms. Evidence is mounting that we have another Super El Niño on the way, similar to the appalling conditions of 1982-83 and 1997-98. Oh great.
It’s unusual for scientists to be talking about an El Niño as early as autumn, however the Australian Bureau of Meteorology is already predicting a 70% likelihood of an El Niño for the summer of 2014-15 and that it could start as early as July. That the temperature indicators are already so strong this far ahead raises the possibility of a ‘Super El Niño’ – or another disastrous heatwave and drought period for the western Pacific, including Australia, Indonesia and the Philippines, as well as increased storm activity on the USA west coast.
Super El Niño events are triggered by higher than normal ocean temperatures in the eastern Pacific and cooler than normal in the western Pacific, triggered by several factors:
• a large area of unusually warm water in the equatorial Pacific
• strong westerly wind ‘blasts’, which push that warm water from the western Pacific towards the east. There have already been 3 recorded westerly blasts, the most recent associated with Tropical Cyclone Ita.
The bigger the west-east temperature differential, and the bigger the volume of warm water being moved, the stronger the El Niño. It’s usually not until the southern hemisphere winter that these measurements become clear but new sub-surface temperature measuring at 50-300m depth is showing strong early signs of temperature movement.
If you live in southern Australia and you haven’t already made efforts to adapt your garden to a drier, warmer climate, I’d suggest you do some serious work over this coming winter.