Thursday, February 17, 2005

Southern Ocean Changes

A multinational team of scientists have discovered significant changes in salinity and temperature of the southern ocean, according to a recent article on Using a network of free-floating submersible measurement robots, the scientific team surveyed roughly 3,000 square kilometers of the southern ocean to measure deep water temperature and salinity.

The team leader, Australian Steve Lintour, described how the deep water of the southern ocean was found to be much colder and less salty that ten years prior. The Yahoo article quotes Mr. Lintour as saying,

"Ocean circulation is a big influence on global climate, so it is critical that we understand why this is happening and why it is happening so quickly," Rintoul said after he and his team docked at Hobart on the Australian island state of Tasmania.

"The surprise was just how rapidly the deepest parts of the ocean are changing, at depths of four or five kilometers (13,200-16,500 feet) below the sea surface," Rintoul said.

"Whether its a natural cycle that takes place over many decades, or it's climate change, it's an indication that the deep ocean can respond much more rapidly to changes that are happening near the surface than we believed possible," he said. "

It is not clear, according to Mr. Lintour, if the changes seen in the ocean temperatures or salinity levels are human-induced changes or part of a normal cycle.

From our high school science classes we all remember the concept of "thermal inertia", which is the ability of a body to resist rapid changes in temperature. Water has a very good thermal inertia, so whatever is the cause of this may be something big and interesting. On the other hand, it may simply be the natural cycling of currents that we are only not beginning to recognize. Just like global warming.

Another point to consider (You knew I couldn't resist!) is that it seems to be well-established science that the oceans 'drive' the atmospheric weather, not the reverse. In other words, the oceans influence the atmosphere by a far larger degree than the atmosphere influences the ocean. That makes sense since the thermal inertial of air is significantly lower than the thermal inertia of water.

As you know if you've read my previous posts, I am a global warming skeptic, and data such as this fuels my skepticism.

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