Thursday, June 17, 2010

Gulf Of Mexico Oil Spill and Weather Implications

It’s Difficult to Believe they Can’t Stop the Leak
Gulf Of Mexico Oil Spill and Weather Implications
By Dr. Tim Ball Thursday, June 17, 2010
Explosion of the rig and the ongoing oil leak in the Gulf of Mexico is a serious disaster exacerbated by media hyperbole and political exploitation from all sides. Failure to deal with it is a travesty and hard to understand. There must be a solution even if it’s drastic, such as a small-scale nuclear device to seal off the flow. Why are they not being used? Do they assume the impact is less than the problem of taking such action? Every day that goes by makes this assumption more wrong. One issue is the impact of weather on the spill, and the spill on the weather.



Dynamics of Earth Atmosphere Systems
The skin is the largest organ in the body yet most people don’t even know it is an organ, or how important it is to health. It is known as an interface, that is a boundary between two completely different environments. It is the area where we interact with the atmosphere and many activities are constantly occurring that are essential to our survival. The surface of the earth is akin to the skin where interactions across its surface are critical to processes in the atmosphere. Nowhere is this truer than for the 70 percent of the surface that is water.

In an ironic twist the adage suggests you calm troubled waters by pouring on oil. Ancient Greeks knew how oil calmed the water and Pliny confirmed it with experiments. Benjamin Franklin, whose scientific method was through practical experiments, tested the idea again in the summer of 1771 on a small lake near London, England. He reports: “…the oil, though not more than a teaspoonful, produced an instant calm over a space several yards square which spread amazingly and extended itself gradually till it reached the lee side, making all that quarter of the pond, perhaps half an acre, as smooth as a looking glass.”

Even small amounts of oil work because it spreads quickly and widely forming a very thin layer, often of only a few molecules. Surface tension is increased which reduces small wave formation and break up of the surface by wind. There is a constant interchange of gases such as oxygen, carbon dioxide and water molecules between the water and the atmosphere and oil reduces these. This is important for the chemistry of the water and air near the surface. Some knowledge of these effects is available from research done to reduce evaporation rates for bodies of water including swimming pools.

Evaporation is the biggest factor because it’s a major transfer mechanism of heat from the Earth to the atmosphere. Solar energy is absorbed at the surface and raises the water temperature by increasing the speed of the molecules. Evaporation occurs when water vapor molecules escape from the surface into the air. Warmer air can hold more water vapor than cold air. The rate varies with three things, water temperature, air temperature and wind. Water and air temperatures are highest in the tropics so rates are highest there. Evaporation creates cooling just as sweating keeps you cool. So any reduction in evaporation means higher water temperatures and cooler air temperatures.

Energy from evaporation is the fuel for a hurricane
With the layer of oil the rate of movement of everything across the interface is significantly altered. Calculating the amount of reduction is difficult because the oil is dispersed by wind and by chemical dispersants. However, the area is large enough to have a discernible effect especially during a hurricane. Energy from evaporation is the fuel for a hurricane. Estimates put rates at 8 million liters an hour for a moderate sized hurricane. This is why hurricanes dissipate very quickly once they move over land.

Evaporation over the Gulf is a major source of moisture for precipitation across the southern US and even as far north as southern Canada in the summer. Calculations of the reduced evaporation and lost precipitation potential are difficult but possible because the area is roughly known (Figure 1).


Figure 1: New York Times map of oil spill on June 14—Source:

The fishing ban area covers 78,264 square miles and the main slick (purple) covers approximately 20,000 square miles. However, it’s almost impossible to determine the impact on precipitation amounts.

Portions of the slick have broken off (lower centre of map) and are caught up in the circulation called a gyre. There is concern it will be transported out around Florida following the flow lines on the map and become part of the Gulf Stream. It will shortly meet with storms tracking in as the hurricane season begins.

This starts in late summer after water, warmed as it crosses from Africa, arrives in the Caribbean with high temperatures, usually above 26°C. Tropical Depressions intensified by the evaporated energy become Tropical Storms and then Hurricanes with each stage defined by the wind speed. If oil is still escaping and spreading, the hurricane will lose some force and winds will decrease slightly. However, the slick will spread over a much larger area and be pushed on higher shores. Storm surges and onshore winds will push the water further inland as the flooding associated with Hurricane Katrina attests.

It is hard to believe stopping the oil is so difficult. Options and ideas have come in from all over the world and they have either been ignored or ruled out. Why? There is the obvious political gain of letting the spill get worse as leverage for cap and trade. But what is BP doing? Why didn’t Obama speak to BP CEO Tony Hayward immediately? Is it because BP wants to capitalize on its alternate energies business?

How can people who claim such competence be so incapable? Is it because they don’t understand the full implications and impacts? Is it because they incorrectly consider them less than more drastic actions the situation demands?

Hopefully, the oil leak is capped soon and BP is held responsible. It should also include Obama’s administration that have completely bungled containment and clean up because of political exploitation. We need more than Obama’s farrago offered in his Oval Office. As Benjamin Franklin wrote, “Here comes the orator! With his flood of words, and his drop of reason.” We need answers to all the obvious questions not being asked or answered.

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