Atmosphere "Bagian bumi yg tak akan habis dibicarakan" :))

If we talk about atmosphere, we will explain about a part of the earth where place that we live. #so sweet. Seriously, this subject is very large. But, writer just tell some reason why this subject is important to learn.

The atmosphere is air layer that composed of gases suspended liquids, and solids that entirely surround the planet (for example the earth). Atmosphere word is taken from greek, there is atmos by mean vapor and sphaira by mean earth ball. In other reference, The “air” you are breathing is actually a mixture of gases. This mixture of gases is known as the atmosphere. 

The atmosphere also contains solid material in addition to the gases above. This solid material is very small, between .1 and 25 thousandths of a millimeter, or micrometer and is known as particulates. To give you some idea how small particulates are, a single grain of table salt is about 100 micrometers in size, and so we are talking about a mass of material that is 1/1000 to ¼ the size of a grain of table salt. In addition to gases and solids, liquids also exist in the atmosphere. The most common one of these is water, good old H20. Water exists in the atmosphere as clouds, rain, and fog, all of which are visible and, therefore, familiar. The table below shows the composition of the atmosphere and the cumulative volume of each compound.

Full Name	Formula	% Volume	# Of Parts	Unit		Cumulative Volume
Nitrogen	N2	78.1%	78 parts per	Hundred		78.10%
Oxygen	O2	20.9%	21 parts per	Hundred		99.00%
Argon	Ar	0.934%	9 parts per	Thousand		99.93%
Water Vapor	H20	0.04%	400 parts per	million		99.97%
Carbon Dioxide	CO2	0.0369%	370 parts per	million		99.99%
Neon	Ne	0.00182%	18 parts per	Million		100.00%
Helium	He	0.000524%	5 parts per	Million		100.00%
Methane	CH4	0.0001842%	2 parts per	Million		100.00%
Krypton	Kr	0.000114%	1 part per	Million		100.00%
Hydrogen	H2	0.0001%	1 part per	million		100.00%
Nitrous Oxide	N20	0.0000315%	315 parts per	billion		100.00%
Carbon Monoxide	CO	0.00002%	200 parts per	billion		100.00%
Xenon	Xe	0.0000087%	87 parts per	billion		100.00%
Ozone	O3	0.000005%	34 parts per	billion		100.00%
Sulphur Dioxide	SO2	0.000002%	20 parts per	billion		100.00%
Ammonia	NH3	0.000002%	20 parts per	billion		100.00%
Formaldehyde	CH20	0.000001%	10 parts per	billion		100.00%
Nitrogen Dioxide	NO2	0.0000003%	3 parts per	billion		100.00%
Nitric Oxide	NO	0.0000003%	3 parts per	billion		100.00%
Hydrogen Sulfide	H2S	0.0000002%	2 parts per	billion		100.00%
Hydrochloric Acid	HCl	0.00000015%	2 parts per	billion		100.00%
Nitric Acid	HNO3	0.0000001%	1 part per	billion		100.00%
Methyl Chloride	CH3Cl	0.00000006%	600 parts per	trillion		100.00%
Freon-12	CF2Cl2	0.0000000544%	546 parts per	trillion		100.00%
Carbonyl Sulfide	COS	0.00000005%	500 parts per	trillion		100.00%
Freon-11	CFCl3F	0.0000000263%	263 parts per	trillion		100.00%
Carbon Tetrachloride	CCl4	0.000000098%	97 parts per	trillion		100.00%
Freon-113	C2F3Cl3	0.000000082%	82 parts per	trillion		100.00%
Methyl Chloroform	CH3CCl3	0.000000056%	47 parts per	trillion		100.00%
HCFC-22	CHClF2	0.0000001525%	153 parts per	trillion		100.00%
HFC-23	CHF3	0.0000000011%	23 parts per	trillion		100.00%
Sulphur Hexaflouride	SF6	0.000000004%	5 parts per	trillion		100.00%
Perfluoroethane	C2F6	0.000000004%	4 parts per	trillion		100.00%
Triflouromethyl Sulphur Pentaflouride	SF5CF3	0.00000000012%	.12 parts per	trillion		100.00%
Sources
1. McGraw-Hill Encyclopedia of Science and Technology, 1987, McGraw-Hill, Inc.
2. Carbon Dioxide Information Analysis Center

Layers of the Atmosphere

So we see that the atmosphere contains gases, suspended liquids, and solids that entirely surround the earth. The earth's gravity pulls these gases, liquids, and solids toward the surface. Not surprisingly, there are more gases closer to the surface and fewer as you move away. Therefore, the earth's atmosphere is denser at the surface and gradually thins as altitude increases.

The atmosphere begins at sea level, (and in some places on land that are just below sea level) and extends outward some 6,000 miles (10,000 km) into space. From the surface to an altitude of 50 miles (80 km) the chemical composition is of the atmosphere is highly uniform. Due to this uniformity, this section of atmosphere is known as the homosphere. The homosphere, or lower atmosphere, is divided into various layers. The troposphere is the layer closest to the surface and it extends outward an average of 11 miles (18 km), though it is thicker at the equator and thinner at the poles. Beyond the troposphere is the stratosphere, which extends from 11 to around 30 miles from the surface. The mesosphere starts at around 30 miles and extends outward to 50 miles from the surface.

Above 50 miles, the chemical composition of the atmosphere changes with altitude. This layer is known as the upper atmosphere or heterosphere. This upper layer is also known as the thermosphere and it extends outward several thousand miles with no real boundary between the upper atmosphere and space.

Though the atmosphere extends outward several thousand miles, one half of the gas molecules that comprise the atmosphere are located within the first 3.5 miles (5.6 km), or 18,840 feet. Fully 90% of the molecules are within the first 10 miles (16 kilometers), or 52,580 feet, and some 97% of gas molecules are packed within the first 18 miles (30 km). Gravity keeps the atmosphere very close to the earth's surface. Also, since most human activities take place from sea level to around 10,000 feet or 2 miles, conditions in the layer of the lower atmosphere closest to the surface, the troposphere, are what affects us day to day. The troposphere, #8 in the diagram, extends outward to about 11 miles, and contains about 90% of the molecules in the atmosphere. 

Natural Changes in the Atmosphere

The troposphere is an extremely dynamic and ever changing system. Every day, the light, clouds, and heat energy in the troposphere go through a million variations. These changes affect daily life in thousands of subtle and direct ways and, for generations, humans have been fascinated by the troposphere’s daily changes, which are known as weather. We all have a sense of what weather is. On some days it is rainy, and some days sunny. Some days are hot and some are cold. Sometimes the wind blows with intense ferocity. 

Daily changes in the troposphere are known as weather. Long term, average conditions are referred to as climate. Weather is more extreme than climate, meaning that daily ranges of temperature, precipitation, pressure, and wind are greater than the long-term extremes of climate. Since climate refers to long-term average conditions, it is more moderate. 

One way to look at the relationship between weather and climate is to take a look at your checking account. The monthly balance for twelve months of a year would represent climate and the daily inflows and outflows of funds, weather. Your daily balances might vary a great deal from day to day while your monthly balances, which are an average of your daily balances, would be more consistent. In the same way, weather changes much more rapidly than climate and you know this from your own experience. One day it might be warm and close to 60 degrees and the next day, cold and in the mid-forties. Climate also changes, but on a much longer time scale. Later in this section on atmosphere we’ll look more closely at climate change.