Water on earth’s surface

As shown in Figure 2.1, the free water on Earth s surface is now transported between the land, atmosphere, ocean, and mantle through a global hydrological cycle. From... 

The global heat cycle drives the hydrological cycle, which in turn controls the salinity of seawater. The most important contributor of heat to the crustal-ocean-fectory is solar radiation. The flux of solar radiation that reaches Earth is termed insolation. Only a fraction of the incoming solar radiation reaches Earth s surfece, because a large portion is either reflected or absorbed by the atmosphere. That which reaches Earth s surface is also either reflected or absorbed. In the end, about half of the incoming radiation is absorbed by the rocks and water on Earth s surfece. (A detailed heat budget is provided... 

Water, as you know, is the most abundant substance on Earth s surface. Unfortunately there is more than enough water in some places, but not enough in others. As well, because water is used and re-used, and because it is such a powerful solvent, it is easily polluted. 

Part of the solar radiation entering the earth s atmosphere is scattered and absorbed by air and water vapor molecules, dust particles, and water droplets in the clouds, and thus the solar radiation incident on earth s surface is less than tlie solar couslanl. The extent of the attenuation of solar radiation depends on the length of the path of the rays through the atmosphere as well as the composition of the atmosphere (the cloud.s, dust, humidity, and smog) along the path. Most ultraviolet radiation is absorbed by the ozone in the upper atmosphere. At a solar altitude of 41.8°, the total energy of direct solar radiation incident at sea level on a clear day consists of about 3 percent ultraviolet, 38 percent visible, and 59 percent infrared radiation. 

Water is the most abundant substance in the human body and the most common substance on Earth, covering approximately 12% of the surface of this planet. All the water found in and on Earth s surface and in the atmosphere is collectively referred to as the hydrosphere. More than 97% of this surface water is located in the oceans. Another 2.1% is frozen in glaciers and polar ice caps. That leaves a meager 0.6% available as liquid freshwater. 

Look again at Figure 26-10. As you can see, water cycles through the atmosphere, on Earth s surface, and under the surface. Can atmospheric processes affect the hydrosphere The answer is most definitely yes. Processes that take place in the atmosphere, such as the formation of acid rain, can have a direct impact on the hydrosphere. The interrelatedness of the components of the environment is an important concept to keep in mind as you explore Earth s water, beginning with the vast and mighty seas. 

On Earth, carbon dioxide was removed from the atmosphere over long periods of time, primarily as the result of the formation of carbonate rocks in the Earth s crust, a process catalyzed by water. As living organisms appeared and evolved on Earth s surface, they contributed to the removal of carbon dioxide—plants through the process of photosynthesis, aquatic animals by incorporating it into their shells. In addition, Earth s average annual temperature was sufficient to allow water vapor to condense into liquid water,... 

Limestone (CaCOs) and dolomite (CaCOs MgCOs), which are widespread on Earth s surface, often enter the water supply. According to Table 4.2, calcium carbonate is insoluble in water. However, in the presence of dissolved carbon dioxide (from the atmosphere), calcium carbonate is converted to soluble calcium bicarbonate [Ca(HC03)2] ... 

Oxygen is the most abundant element on Earth s surface, occurring in air as the free element, combined with hydrogen in water, and combined in innumerable oxides, silicates, carbonates, and phosphates. Virtually all O2 has a biological origin, having been formed for billions of years by photosynthetic algae and multicellular plants in an overall equation that looks simple but involves many steps ... 

When did liquid water first appear on Earth s surface ... 

When Did Liquid Water First Appear on Earth s Surface ... 

You might ask why there is so much concern about polluted water when water is the most abundant substance on Earth s surface. Oceans (with an average depth of 2.5 mi) cover about 72% of Earth. They are the reservoir of 97.5% of Earth s water. Only 2.5% is freshwater. Water is also the major component of all living things (Table 11.2). For example, the water content of human adults is 70%—the same proportion as for Earth s surface. 

Without the greenhouse effect, the temperature on Earth s surface will plummet to 0°E (-18°C), and all water on Earth, including the oceans, will freeze Life as we know it will not be possible. 

In most natural waters at near neutral pH, Cr is the dominant form due to the very high redox potential for the couple Cr /Cr (Rai etal., 92>9). Chromium(III) forms strong complexes with hydroxides. Rai et al. (1987) report that the dominant hydroxo species are CrOH at pH values 4-6, Cr(OH)3 at pH values from 6 to 11.5, and Cr(OH)4 at pH values above 11.5. The OH ligand was the only signifrcant complexer of Cr in natural aqueous solutions that contain environmental concentrations of carbonate, sulfate, nitrate, and phosphate ions. The only oxidant in natural aquatic systems that has the potential to oxidize Cr ° to is manganese dioxide. This compound is common on Earth s surface and thus... 

The reaction of OH radical with nitric acid (HONO2, HNO3) in the stratosphere is important as it reproduces active nitrogen from the reservoir molecule HONO2 in the NOx cycle. Although in the troposphere, water-soluble nitric acid is mainly removed by wet deposition into cloud and fog, and dry deposition on earth s surface, the OH reaction as well as photolysis are also important as removal processes and as active nitrogen regenerating process in the upper troposphere where clouds are not abundant. 

Water (H2O) is the most abundant compound on Earth s surface, covering about 70%. In nature, it exists in liquid, solid, and gaseous states. It is in dynamic equilibrium between the liquid and gas states at standard temperature and pressure. At room temperature, it is a tasteless and odorless liquid, nearly colorless with a hint of blue. Many substances dissolve in water and it is commonly referred to as the universal solvent. Because of this, water in nature and in use is rarely pure and some of its properties may vary slightly from those of the pure substance. However, there are also many compounds that are essentially, if not completely, insoluble in water. Water is the only common substance found naturally in all three common states of matter and it is essential for all life on Earth. Water usually makes up 55% to 78% of the human body. 

Hampel A, Hetzel R, Maniatis G (2010) Response of faults to climate-driven changes in ice and water volumes on Earth s surface. Phil Trans R Soc A 368 2501-2517... 

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