The Sun, the Earth and the Atmosphere By: Rafaela Aulestia, AdriĂ n Lua & Ana Martina Romero Cordero 8A
The Sun The sunÂ´s responsibility on certain phenomena the sun, the main source of our energy and the object the entire universe revolves around, pretty much affects every single thing that we come across with. Sun is the creator of winds, because with its radiation, the sun gives heat to the earth. This heat creates temperature differences that come along with pressure differences and create winds. This heat can also cause a mix in the atmosphere which brings stronger winds. The sun is also ultimately responsible for other phenomena, called ocean currents. Ocean currents are affected by the sun because as sun heats up the atmosphere, it creates winds that move the surface of the sea with friction and drag along the water surface. As well, the sun differs the density of the ocean by changing its temperature, along with the amount of salinity that there exists. Here, there is a thermohaline circulation that is caused as water evaporates and it becomes saltier and denser. The other factor that affects
the ocean current is the earthÂ´s rotation. In addition, the sun is also responsible for a role in the water cycle. The sun heats the water through electromagnetic radiation and causes its particles to move faster, creating heat and changing state of mater from liquid to gas; through a process called evaporation. The sun is responsible for heating the water in oceans or fresh water resources in the earth. Finally, the sun also takes a role in plant growth. Natural sunlight provides nutrients and a very high intensity, which plants need in order for them to complete the
photosynthesis process that cannot even be reproduced by artificial lights. On the other hand, the sun can be considered the ultimate source of energy, because any
type of energy we use to create artificial light comes from the sun. The sun is a very powerful organism in our universe, and we can see that it affects us all in major scale.
Energy in the Atmosphere The Atmosphere is responsible from most of the changes that occur in our weather and how do we receive the energy from the Sun. The transfer of energy through electromagnetic waves is called radiation, the process in which we obtain our energy. The energy that we receive from the sun is obstructed by the atmosphere and the layers that are in it. A small portion of the energy liberated by the sun is absorbed by certain gases inside the atmosphere such as ozone and water vapor. The other portion of energy is reflected back to space by the clouds. The three main ways in which we receive energy is through conduction, convection and radiation. Conduction is the transfer of energy from one particle to another without the movement of matter itself. Because the air
atmosphere is partially filled with air most of the conduction that occurs in the atmosphere is right at the surface. At night the ground colds down and the cold air drives the heat away from the air. But during the day, the sun radiation heats up the ground and by that process it also heats up the air around it. Another process that takes place in the atmosphere is convection which is the transfer of heat by the movement of any substance. In the atmosphere this process occur which large, medium and small portions of air, that rise and sink. These movements distribute heat and moisture but also contribute to the creation of clouds, storms and dissipation. The equator, where we are located receives much more sunlight than the poles so the air is warmer. This hot air goes up to the poles and the cold air from the poles sink. The way we receive our energy is from radiation which was already explained. We receive electromagnetic waves that are seen in the electromagnetic spectrum such as ultraviolet rays.
We can visually notice the different seasons in our world, when the environment around us starts to change and certain aspects shift. There are four major changes that we can see as the year goes by: spring, summer, autumn and winter. These changes are caused because of the shape of the world, which is tilt on itÂ´s axis. This axis is tilted perpendicular to the plane of the ecliptic by 23.45Â°. This means that as the Earth tilts, different parts of the world are exposed and oriented into the sunlight. Depending on
each hemisphere, summer is warmer than winter because of the straightness and in the direction and intensity with the sun rays hit the earth. There are solstices and equinoxes that also have to do with this shift in the position of the earth. Around December 21, when winter solstice occurs and around June 21, when summer solstice takes place, the sun reaches its farthest northern and southern declinations. Equinoxes, instead, are given when day at night have the same duration because the sun crosses the celestial equator. This happens in late March in November.
Wind Wind is a result of air changing form high to low pressures. Because of the air rotation, the air is deflected to the right in order for it to flow around high pressure areas. The closest the high and low pressure areas are, the stronger the wind is. This is called a pressure gradient. Friction from the ground slows the wind down at the surface of the earth. That is why, on the day when the atmosphere is mixing the pressure with the air this effect is minimized, through convective mixing. Wind can be thought of one way that the atmosphere moves excess heat around. Wind helps transport heat on the surface of the Earth from warmer to cooler regions.
The SunÂ´s direct rays hit the equator, were air is heated and leaves low pressure areas behind. Moving thirty degrees north and south of the equator, warm air from the equator will begin to cool and sink. Most of this cooling sinking air will move back to the equator. The remaining air flows to the poles. This air movement toward the equator is called trade winds, which is made of warm, steady breezes that blow continuously. On the other hand, the carioles effect causes trade winds seem like they would be curving to the west despite if they are traveling from south to north. When the trade winds come from the south and meet at the equator, the covering trade wind produce upward winds that, as they are heated, there are no longer steady surface winds, creating a calm area called doldrums. Some wins that move towards the pole appear to curve at the east, are called prevailing westerlies because of this. They are responsible for many of the weather movements across the United States and Canada. In effect, at about sixty degrees, the prevailing westerlies join the polar easterlies; that form when the atmosphere that is over the pole cools and sinks and spreads over the surface, it flows away from the poles due to the Coriolis Effect. This reduces the upward motion. Changes in wind direction are hard to visualize at times.