Article
The 2010/2011 Ningaloo Niño
The worst marine heatwave to hit Western Australia in the preceding decade
Ronni King
Murdoch University
The Ningaloo Niño marine heatwave caused
mass destruction to the ecosystem along the
coast of Western Australia in 2011. While the
occurrence of a Ningaloo Niño event may be
linked to a La Niña, the strength of this particular
event was unprecedented, which saw sea surface
temperatures rise by up to 2.5°C extending along
the whole coastline. A particularly strong La
Niña in the months leading into the Ningaloo
Niño as a result of the negative Pacific Decadal
Oscillation is associated with an unseasonably
strong Leeuwin Current due to a lower meridional
pressure gradient in the overlying atmosphere
and weakening southerly wind anomalies,
typical of an austral summer. An increase in
water velocity helped transport masses of warm
surface water further south than ever before. The
driving forces behind the strengthened Leeuwin
Current suggest this was the primary cause of the
Ningaloo Niño marine heatwave.
Figure 1 (right). Monthly anomalies for
SST (°C) and geostrophic velocity (ms -1 ) for
December, January, February and March
(2009/2010–2010/2011). Arrow direction
and length indicates water movement
and strength. Images obtained from the
Integrated Marine Observing System
(IMOS) Ocean Current website 2017.
BAMOS
Sep 2018
9