Wednesday, January 26, 2011

La Niña

This morning the harbour and its outside coast line were obscurred by clouds of very moist air.
The typically golden sandstone of North Head was unfamiliar in this dark atmospheric cloak.
And the short journey around to Shelly Beach was accompanied by the feeling that we were paddling along a foreign coastline.

The large-scale physical condition that seems to be driving this localised humid atmosphere (and the significant rainfall experienced recently along much of the east coast of Australia) is the embodied heat energy of the sea water in the western Pacific. As the diagram below from the CSIRO describes, we have a La Niña event in full-blown occurence ... 

At least the Bonito seem to like the warmer water.

On the return journey to the harbour the clouds of moisture continued to tumble over the face of North Head like a slow-motion waterfall. (Peter's sail just visible on the left)

Click on the Sea Surface Temperature chart (to the right) to see the cell of hot water that is circulating east of Sydney at the moment.
NOTE - if you're reading this posting many days after 26th January 2011then the cell of hot water will have evolved along its merry way to be replaced by some other body of cooler or warmer water.