Another Arctic Scare

By Paul Homewood 

  

http://www.bbc.co.uk/news/science-environment-34324439

 

From the BBC:

 

Oceanographers have gathered fresh evidence that turbulence in the Arctic Ocean, driven by the wind, is stirring up heat from the depths.

As dwindling ice exposes more water to the wind, this turbulence could close a vicious circle, accelerating the melt.

The research team has measured heat rising from below that matches what is arriving from the autumn sun.

They spoke to the BBC by satellite phone as their month-long voyage headed back into port.

Although their findings are preliminary, the "ArcticMix" team has been taken aback by what they’ve seen in the raw data.

"The strength of heat coming up from below the surface has been as strong as the heat coming down from the Sun," said the mission’s chief scientist, Jennifer MacKinnon, of the Scripps Institution of Oceanography at the University of California San Diego.

"Admittedly, the days are getting short here, and so the sunlight is not incredibly strong at this latitude. But still, that very rarely happens; that’s kind of blown us all away."

The source of that deep heat is a layer of warm water that is saltier – and therefore denser – than water at the surface.

"There’s a reservoir of heat in the Arctic Ocean, well beneath the surface, that historically – when there’s been a lot of ice – has been fairly quiescent," Dr MacKinnon explained. "It’s just been sitting as a warm, salty puddle beneath the surface."

Now that shrinking sea ice is exposing more water to the air, scientists are worried that this warm, salty puddle might get stirred upwards.

 

My first reaction is that they have a new toy, and think they are therefore seeing things that have never happened before.

But what this report really highlights is a total lack of appreciation of just how the Earth’s energy budget actually works, something we come across time and time again when people talk of “Arctic warming” .

 

NASA explain:

 

The amount of sunlight the Earth absorbs depends on the reflectivness of the atmosphere and the ground surface. This satellite map shows the amount of solar radiation (watts per square meter) reflected during September 2008. Along the equator, clouds reflected a large proportion of sunlight, while the pale sands of the Sahara caused the high reflectivness in North Africa. Neither pole is receiving much incoming sunlight at this time of year, so they reflect little energy even though both are ice-covered.

 

The differences in reflectivness (albedo) and solar illumination at different latitudes lead to net heating imbalances throughout the Earth system. At any place on Earth, the net heating is the difference between the amount of incoming sunlight and the amount heat radiated by the Earth back to space . In the tropics there is a net energy surplus because the amount of sunlight absorbed is larger than the amount of heat radiated. In the polar regions, however, there is an annual energy deficit because the amount of heat radiated to space is larger than the amount of absorbed sunlight.

 

This map of net radiation (incoming sunlight minus reflected light and outgoing heat) shows global energy imbalances in September 2008, the month of an equinox. Areas around the equator absorbed about 200 watts per square meter more on average (orange and red) than they reflected or radiated. Areas near the poles reflected and/or radiated about 200 more watts per square meter (green and blue) than they absorbed. Mid-latitudes were roughly in balance.

The net heating imbalance between the equator and poles drives an atmospheric and oceanic circulation that climate scientists describe as a “heat engine.” (In our everyday experience, we associate the word engine with automobiles, but to a scientist, an engine is any device or system that converts energy into motion.) The climate is an engine that uses heat energy to keep the atmosphere and ocean moving. Evaporation, convection, rainfall, winds, and ocean currents are all part of the Earth’s heat engine.

http://earthobservatory.nasa.gov/Features/EnergyBalance/

 

 

Put simply, the process discovered by the oceanographers is actually the Earth’s heat engine working just as it designed to, transferring heat to the high latitudes, where it will radiate into space.

Forget about talk of a rapidly warming Arctic; the warmer the atmosphere there, the faster heat will radiate into space. In other words, it is cooling the Earth down.

Ocean cycles and processes dominate the Earth’s climatic system, and there are times such as now when excess heat is transported to the Arctic to escape. At other times, the process slows down, allowing sea ice to increase and insulate the ocean.

In this way, the Earth maintains its equilibrium.