Earth's Oceans and Deserts Help (page 3)

The Oceans

The surface of Earth is largely covered by mineral-rich oceans of water. The largest of these, if seen from a certain vantage point in space, covers almost half the planet. This is the Pacific Ocean ; it was given this name by some Earth dweller who saw it at one of its more peaceful moments. ( Pacific means “peaceful” or “tranquil.”) However, this ocean is not always calm. Revolving storms, called hurricanes in the eastern Pacific and typhoons in the western Pacific, churn the waters and transport excess heat from the tropics toward the polar regions.

Hurricanes also occur in the Atlantic Ocean and in the Indian Ocean. The storms form at lower latitudes, and they almost always work their way either onto a land mass, where they dissipate, or toward cold water, where they expire from lack of heat to sustain their winds. Occasionally, one of these storms strikes a human-made anthill. Some of the planet’s most elaborate anthills are built directly in known hurricane tracks. I wonder why the human Earth dwellers construct so many of their communities in such places?

The waters flow in slow currents around and around the oceanic basins, generally clockwise in the northern hemisphere and counterclockwise in the southern. This gives rise to warm ocean currents along the eastern shores of the continents and cold currents along the western shores. This has a profound influence on the distribution and movement of weather systems in the planet’s atmosphere. When something happens to upset the regularity of these currents, the climate changes over much of the planet. These cycles are natural and have been taking place for millions of human-defined years. However, almost every time such a cycle recurs, especially the sort known as El Niño where the eastern equatorial Pacific waters switch from cold to warm, the humans call the resulting weather a disaster .

The oceans are critical to the balance of life on Earth. They are like the lungs and blood of a living organism. Tiny life forms called plankton live in the oceans; these are eaten by larger life forms such as the fish . Fish are a favored food among the two-legged humans. However, humans dump toxic chemicals and hydrocarbon dregs into the oceans, where they work their way into fish and then into their brothers’ and sisters’ bodies, causing terrible illnesses and suffering. Humans know about this. We have heard them talk about it in their electromagnetic broadcasts. Why do they continue to knowingly harm themselves in this way?

The Land Masses

The oceans tend to heat up and cool down slowly. They hold heat energy. Land masses are just the opposite. They heat up and cool down rapidly. This contrast, along with the oceanic currents and the prevailing differences in temperature between the tropics and the polar regions, creates the climate and weather variations on this third planet from the star we call Sol. Earth is the only planet with weather varied enough to motivate the evolution of life but not so violent or hostile as to exterminate such life before it gets a chance to evolve.

In some places water accumulates in the atmosphere and then precipitates onto land masses in great amounts. This can happen either as liquid water, in which case it is called rain , or as frozen water, known as snow . There are other, less common forms of precipitation, such as hail , but these do not contribute much to the overall ecological system of the Earth.

In the regions where precipitation is abundant and mostly liquid, forests of tall plants grow. Some of these plants are cut down and used as materials by the two-legged humans in the construction of dwellings in their anthills. It is amazing how many different geometries have been invented for these dwellings! The plants, called trees , make ideal building material, and they can be replenished by intelligent management. Unfortunately, in some regions of the planet no attempts are made to replenish the supply of trees. Humans obviously know the supply of trees is not infinite and eventually will be depleted if balance is not maintained. Do they not care about their own future?

Layers Of The Atmosphere

The Earth’s atmosphere is 78 percent nitrogen at the surface and 21 percent oxygen. The remaining 1 percent consists of argon, carbon dioxide, ozone, and water vapor. The temperature of the atmosphere varies considerably; it can rise to about 55°C (130°F), or plunge to around –80°C (–112°F).

The lowest layer of the atmosphere, rising from the surface to approximately 16 km (10 mi) of altitude, is the troposphere . This is where all weather occurs; most of the clouds are found here. In the upper parts of the troposphere, high-speed rivers of air travel around the planet in a generally west-to-east direction. There can be two or three of these rivers in the northern hemisphere and two or three in the southern hemisphere. The strongest of these rivers, called jet streams , carry high- and low-pressure systems from west to east at temperate latitudes, primarily between 30°N and 60°N, and between 30°S and 60°S.

Above the troposphere lies the stratosphere , extending up to approximately 50 km (30 mi) of altitude. Near the upper reaches of this level, ultraviolet radiation from the Sun causes oxygen atoms to group together into triplets (O ₃ ) rather than in pairs (O ₂ ), as is the case nearer the surface. An oxygen triplet is a molecule known as ozone . This gas has the unique property of being opaque to ultraviolet rays. Thus oxygen atoms form a self-regulating mechanism that keeps the Earth’s surface from receiving too much ultraviolet from the Sun. Certain gases are produced by industrial processes carried on by the two-legged humans; these gases rise into the stratosphere and cause the ozone molecules to break apart into their individual atoms. This makes the upper stratosphere more transparent to ultraviolet than it would be if nature had its way. Some humans have demonstrated that if this process continues, it could have an adverse effect on all life on the planet. Other humans do not believe this and continue to produce these potentially dangerous industrial by-products.

Above the stratosphere lies the mesosphere , extending from 50 km (30 mi) to an altitude of 80 km (50 mi). In this layer, ultraviolet radiation from the Sun causes electrons to be stripped away from atoms of atmospheric gas. The result is that the mesosphere contains a large proportion of ions. This occurs in a layer that communications engineers call the D layer of the ionosphere .

Above the mesosphere lies the highest layer of the Earth’s atmosphere, known as the thermosphere . It extends from 80 km (50 mi) up to more than 600 km (370 mi) of altitude. This layer gets its name from the fact that the temperature is extremely high, even hotter than at the surface of Venus or Mercury. However, these high temperatures do not have the devastating effects they would have if they existed at the surface because the atmosphere at this level is so rarefied. Ionization takes place at three levels within the thermosphere, called the ionospheric E layer, F1 layer , and F2 layer . Sometimes, particularly at night, the F1 and F2 layers merge together near the altitude of the F2 layer; the resulting layer is called the F layer . Figure 8-4 is a diagram of the Earth’s atmosphere showing the various layers and the ionized regions.

Figure 8-4. The Earth’s atmosphere, showing the ionized layers.

Excerpt From A First Officer’s Journal

I have just received a stern warning from the authorities back home on Epsilon Eridani 2. Their mandates are as follows:

• Our Earth landing assignments have been reduced from 10 to 3.
• We are not to land within 50 km (30 mi) of any place known to be populated, even sparsely, with the two-legged life forms that call themselves Homo sapiens .
• We are to keep our radar and optical cloaking devices activated at all times.
•  
• If we accidentally happen to encounter any Homo sapiens , we are to explain to them that we are part of a “Hollywood movie set” and then ask them to leave.

This seems to defeat the most important part of our mission: to find out exactly what makes Homo sapiens behave as they do. However, I can’t fight the bureaucracy of Epsilon Eridani 2! I will have to be content with looking at these creatures, whom I have decided to call bipedal ants , through telescopes while in orbit and analyzing their migration patterns with radar and computer programs.

North Atlantic Ocean

We descend into the middle of the Azores-Bermuda high-pressure system in the North Atlantic Ocean, hoping to find calm conditions. It is the part of the Earth year that the bipedal ants call April , when hurricanes are unknown in this part of the planet. Nevertheless, when we reach the ocean, we find that there are huge waves on the surface. The waves come from the north, and we recall that storms can track across the North Atlantic at any time of the year.

In the northern-hemispheric spring, storms follow the jet stream, coming off the North American continent near the mouth of the St. Lawrence Seaway and taking paths at high latitudes toward Europe. Our meteorology expert on the main ship confirms that one of these storms is passing near Iceland, and it is responsible for generating the waves. We are surprised that waves can travel so far and still be so large, but the main-ship radar telescope indicates that their effects reach all the way south to Antarctica.

The atmosphere is perfectly calm; there is no wind as we land and observe a temperature of 23°C (73°F) at high noon. We float like a cork on the swells, which measure 11 m (36 ft) from crest to trough. The surface of the water is smooth except for these sine-wave-shaped swells, a most remarkable phenomenon.

By sunset, the temperature of the atmosphere has hardly changed; it is 22°C (72°F). At midnight, the atmospheric temperature has gone down to 20°C (68°F), and just before sunrise on the day after our landing, it is at its minimum of 19°C (66°F). This small temperature variation between day and night confirms our theory that the oceans keep the lower atmospheric temperature relatively stable. The water temperature is measured at 20°C (68°F).

We remain on the surface of the ocean, examining the abundant life in the water, for exactly one solar day. We see no signs of the bipedal ants, either on the surface of the ocean or in the atmosphere above it, even though we have been told that aircraft will fly overhead and one of them will descend to investigate us. We are relieved when we lift off at noon, exactly 24 Earth hours after we landed. Because of the violent and continuous motion induced by the waves, I have lost 2.5 kilograms (kg) of body weight. This is 5.5 pounds (lb) in the Earth’s gravitation. It has taken place because I have been unable to eat or drink anything for the past 24 Earth hours without having it come back up. Many bipedal ants suffer this same malady when they are first introduced to oceanic travel; they call it sea-sickness .