Friday, July 4, 2014 5:05 PM
Don’t get me wrong; I think Earth Observatory is a wonderful internet resource and a fine flagship for NASA…
But now and again the tendency to think eludes their PR branch.
Australia’s western shore, Leeuwin Current, unlike most western shore continental currents, flows toward the pole (away from the equator), carrying warm tropical water into a cold ocean. In the MODIS image from NASA’s Aqua satellite taken on 6 June 2014, warmer water is orange and pink, while cooler water is purple.
It is the world’s longest coastal current, extending 3,400 miles from the North West Cape to the west coast of Tasmania and moderates the climate, making it hospitable to marine species normally found much closer to the equator. Its warmth also encourages rain to fall on western Australia, saving it from the extreme dryness found on the south-western shores of the other southern continents. Without the current, western Australia might resemble South America’s Atacama desert or southern Africa’s Namib desert.
The current normally contains limited nutrients, the ocean is a desert of repressed upwelling, surface waters seldom get recharged with nutrients from the ocean floor.
In the 6 June image, high concentrations of chlorophyll in yellow and lower concentrations in blue are found in the warmest parts of the current. The Leeuwin Current is extremely prone to eddies and meanders. >>In the autumn, the current intensifies, flowing faster. The stronger eddies stir the water, allowing nutrients to reach the surface and fueling plankton blooms. In the winter, the blooms continue due to cooler temperatures and storms that agitate the water.<<
What actually happened is that the anticyclone normally found over the ocean at Australian latitudes, and which tends to cross the continent or pass along the southern shore in a 5 day wave; was blocked in the positive AAO phase that is due to end this coming Wednesday (9 July 2014.)
This positive AAO phase completely changes the behaviour of the planet due to its effect on fresh water flows north from Antarctica: https://weathercharts.wordpress.com/category/bom-2/
There has obviously been an abundance of upwelling “with nutriments from the ocean floor”. I dare say something similar -or its polar opposite, is occurring along South American and African coastlines.