The Atlas Barrier

I think I have solved a mystery of the geography of the United States and it has opened up the possibility of gaining a greater understanding of weather and the atmosphere as well.

BARRIER ISLANDS

The mystery concerns the extensive barrier islands that exist offshore along so much of America's Atlantic and Gulf of Mexico coastlines. The states that are best-known for these barrier islands are: North Carolina, Florida and, Texas but they can be found along the coasts of many other states also.

These barrier islands were formed by hurricanes over millions of years and can easily be seen on any map. Here is a map link but it would be even better to follow along with a world atlas. http://www.maps.google.com/ . These barrier islands are extensive along the Atlantic and Gulf coasts of America, Mexico and, islands of the Caribbean. But none are to be found as we get closer to the equator.

Starting at New York's Long Island, we see such a barrier island along it's south coast. Barrier islands continue along the coast southward through New Jersey, Delaware, Maryland and, Virginia. But these are relatively minor in comparison with a state really known for it's barrier islands, North Carolina. The barrier islands here are so extensive as to encompass Albermarle and Pamlico Sounds.

On Florida's Atlantic coast, Titusville, Melbourne and, Miami Beach as well as the John F. Kennedy Space Center are built on barrier islands. The islands are generally less prominent on Florida's Gulf coast but are very noticable at Fort Myers-Cape Coral and from Sarasota to Bradenton. The land on which Clearwater and St. Petersburg are located is too wide to be a barrier island.

With the exception of the northwest stretch of the Florida coast, barrier islands continue all along the U.S. Gulf Coast and southward into Mexico. The islands are particularly wide in Texas and northern Mexico. There are two notable stretches of barrier island along the Caribbean coast of southern Mexico, at Ciudad Madero-Tampico and also at Ciudad de Carmen. However, as we move southward along the coast of Central America, there are practically no barrier islands at all.

About half of the north coast of Cuba is barrier island, and another chain is south of the island. The shallow waters around the Bahamas was once land worn away by advancing continental shelves but the islands themselves are mostly elongated in shape as we would expect barrier islands to be. The island of Bermuda also has the same shape and may well be primarily a barrier island. The Turks and Caicos Islands as well as the Cayman Islands seem to be barrier islands also.

However the Lesser Antilles, the string of islands from Puerto Rico to Trinidad are volcanic in origin and are not barrier islands. Neither is the Great Barrier Reef to the east of Australia, which is composed of coral.

One thing is very obvious to me. These barrier islands are located just where hurricanes tend to come ashore. The more hurricanes tend to meet land at a certain coastal point, the more extensive the barrier islands will be at that point. There is an idea that these islands were formed by meltwater at the end of the last ice age but I consider that as virtually impossible. For one thing, the barrier islands are more extensive in the south than the north.

The reason that no barrier island is seen adjacent to New Orleans, which was struck by Hurricanes Katrina and Rita in 2005 is that any such island was buried by the sediment from the river which formed the Mississippi Delta. The barrier islands on Florida's Gulf coast can be considered as "reverse" barrier islands because they were formed by storms that had already passed over, not ones that were approaching. It is true that hurricanes fade out over land but the lands in the Caribbean and Gulf of Mexico such as Cuba, Hispaniola and, Florida are not wide enough to stop hurricanes from reaching the Texas and Mexico coasts.

There is actually a dynamic interplay between the continental shelves and the barrier islands. The mass of land that was once where the Bahamas are located has mostly disappeared but the barrier islands remain because they are being continuously rebuilt by storms. Florida and Mexico's Yucutan Peninsula were once far larger than today but are sorrounded by vast areas of shallow water because they have been eroded away by advancing continental shelves. The expanse of shallow water along the south coast of eastern Cuba is a result of the same process.

HURRICANE FORMATION AND MOVEMENT

Hurricanes form because the motion in their circular vortex is a vector between the vertical rising of wet air and the spin of the earth. Hurricanes are limited to a certain range of latitudes because there is not enough heat to generate the powerful vertical movement of air at high latitudes and there is not enough spin too near the earth's equator. This is also why extensive barrier islands are not found near the equator and fade out at high latitudes.

The root of the circular motion that gets started is the polarity of diatomic oxygen and nitrogen. Small eddys merge together to form a large vortex as more and more air gets pulled in. The reason that there is no such extensive barrier islands along the Pacific Coast of North America is very simple, the hurricanes that form the barrier islands always move westward or northwestward.

I can explain why but it requires a new understanding of the relationship between the atmosphere and the earth. Let's apply the concepts of astronomy to meteorology and think of each atom in the atmosphere as a tiny moon that orbits the earth. Atoms in the atmosphere are bound to the earth by gravity but do have more gravitational freedom than those atoms that are actually attached to the earth. The circular vortex that forms counteracts the earth's gravity and the storm, while still gravitationally bound to the earth, becomes less bound than the sorrounding air that is not part of the vortex.

The tremendous centrifugal force outward creates the very low pressure that is within the hurricane. The earth rotates eastward while the molecules of air within the hurricane become semi-independent of the earth's gravity due to their rapid circular motion. The hurricane does move eastward along with the rotation of the earth but it is less bound to the earth by gravity than the sorrounding air that is not in the vortex. This causes the hurricane to move eastward, but more slowly than the surface of the earth. Thus, hurricanes seem to us to always move westward or northwestward but it is actually because the earth is rotating us eastward into the hurricane.

My hypothesis is that to fully understand circular storms, we must consider the atmosphere in astronomical terms is borne out by the tremendous winds high above the earth in the stratosphere. If it is the uneven heating of the earth's surface by the sun that is the primary factor in causing the movement of air, then we can logically assume that winds will be greatest near the earth's surface. Ten kilometers up in the sky, the air is much thinner and colder but that is where the tremendous winds of the stratosphere are to be found.

How can this be if the winds should be the most intense closest to the earth's surface? If you want to see how fast the winds can be at high altitudes, you need only look at those high, wispy cirrus clouds. These are below the stratosphere, in the high troposphere, but they are always lined up in the direction of the winds at that altitude.

The higher winds at higher altitudes can be easily explained by my concept of the atmosphere in astronomical terms as trillions of tiny moons bound by the earth's gravity. Those atoms at higher altitudes are less bound by the earth's gravity than those at lower altitudes. So, the air at high altitudes is perceived by us as often moving at very high speeds but it is actually the earth rotating under this air, although there is also lateral movements.

So, you may be wondering why hurricanes apparently move to the north as well as to the west if the earth rotates eastward. The answer to this lies in the curvature of the earth. Due to the north-south span of a hurricane, the earth's surface under the northern part is moving more slowly than the area under the southern part if we are in the northern hemisphere. This pulls the hurricane northward to some extent.

Imagine a log on ground that is moving under it, but the ground at one end of the log is moving faster than the ground at the other end. The log would be pulled toward the end that is moving more slowly.

As the earth rotates it is, of course, moving fastest at the equator because that is where it's circumference is greatest. But it's actual spin at the equator as seen from outside is zero, that is why hurricanes do not form near the equator even though that is where it is the hottest. The spin increases as we move away from the equator and it increases faster as we get further from the equator due to the nature of a sphere. The decrease in circumference by latitude increases as we move to higher latitudes meaning that the earth has more spin the higher the latitude and thus hurricanes are drawn away from the equator.

THE ATLAS BARRIER

So, why did I name this posting "The Atlas Barrier" and what is the discovery in American geography that I claim to have made?

First of all, one curious fact about these barrier islands is that they are almost completely absent along the Atlantic coast of South America. The reason is a fact that is known already. The dust from north Africa that gets swept out to sea by the easterly winds there is a vital component in the formation of hurricanes over the ocean because it provides the condensation nuclei necessary for cloud formation.

If hurricanes form over the ocean and move westward because the earth rotates eastward then why do we not see similar extensive barrier islands along the coasts of China and Vietnam? The obvious answer is that there is no source of dust to the east there. In fact, there is no system of barrier islands anything like as extensive as those described above anywhere in the world.

One curious and unexplained fact of American geography is that there are very extensive barrier islands on the coasts of North Carolina and Florida but far fewer on the coast in between of Georgia and South Carolina.

Considering that dust from north Africa is necessary to the formation of the hurricanes that build these islands, I do not think it is a coincidence that the highest peaks of the Atlas Mountain range in Morocco is at about the same latitude and is of about the same length as the stretch of coast in South Carolina and Georgia that is relatively free of barrier islands.

Dust from north Africa carried out to sea north of what I will call "The Atlas Barrier" goes to form storms that will meet land at North Carolina or sometimes northward and dust carried out to sea from south of this barrier will go to form hurricanes that will strike Florida, the Gulf area or the Caribbean.