Hydrological cycle atmosphere

Rogers A.N. Bromwich D.H. Sinclair E.N. and Cullather R.I. (2001). The atmospheric hydrologic cycle over the Arctic Basin from reanalyses. Part 2. Interannual variability. Journal of Climate, 14(11), 2414 -2429. 

Water is omnipresent on the earth. Constant circulation of water from the ocean to the atmosphere (evaporation) and from the atmosphere to land and the oceans (precipitation, mnoff, etc) is generally known as the hydrologic cycle (see Fig. 1) (1 2). Within the hydrologic cycHc, there are several minor and local subcycles where water is used and returned to the environment. 

Land/atmospheric interfacial processes which impact climate and biological activity on earth are illustrated in Figure 3. Emissions of carbon dioxide, methane, nitrogen dioxide, and chlorofluorocarbons (CFCs) have been linked to the transmission of solar radiation to the surface of the earth as well as to the transmission of terrestrial radiation to space. Should solar radiation be an internal process or an external driver of the hydrologic cycle, weather, and air surface temperatures Compounds of sulfur and nitrogen are associated with acidic precipitation and damage to vegetation, aquatic life, and physical structures. 

Five components of the hydrosphere play major roles in climate feedbacks - atmospheric moisture, clouds, snow and ice, land surface, and oceans. Changes to the hydrologic cycle, among other things, as a result of altered climate conditions are then referred to as responses. Interactions with climate can best be explored by examirung potential response to a climate perturbation, in this case, predicted global warming. 

They deliver water from the atmosphere to the Earth s surface as rain or snow, and are thus a key step in the hydrologic cycle. 

Only two possibilities exist for explaining the existence of cloud formation in the atmosphere. If there were no particles to act as cloud condensation nuclei (CCN), water would condense into clouds at relative humidities (RH) of around 300%. That is, air can remain supersaturated below 300% with water vapor for long periods of fime. If this were to occur, condensation would occur on surface objects and the hydrologic cycle would be very different from what is observed. Thus, a second possibility must be the case particles are present in the air and act as CCN at much lower RH. These particles must be small enough to have small settling velocity, stay in the air for long periods of time and be lofted to the top of the troposphere by ordinary updrafts of cm/s velocity. Two further possibilities exist - the particles can either be water soluble or insoluble. In order to understand why it is likely that CCN are soluble, we examine the consequences of the effect of curvature on the saturation water pressure of water. 

The energy that powers terrestrial processes is derived primarily from the sun and from the Earth s internal heat production (mostly radioactive decay). Solar energy drives atmospheric motions, ocean circulation (tidal energy is minor), the hydrologic cycle, and photosynthesis. The Earth s internal heat drives convection that is largely manifested at the Earth s surface by the characteristic deformation and volcanism associated with plate tectonics, and by the hotspot volcanism associated with rising plumes of especially hot mantle material. 

As a compound water is remarkable. It is the only inorganic liquid to occur naturally on earth, and it is the only substance found in nature in all three physical states, solid, liquid and vapour (Franks, 1983). It is the most readily available solvent and plays a vital role in the continuation of life on earth. Water circulates continuously in the enviromnent by evaporation from the hydrosphere and subsequent precipitation from the atmosphere. This overall process is known as the hydrologic cycle. Reports estimate that the atmosphere contains about 6 x 10 litres of water, and this is cycled some 37 times a year to give an annual total precipitation of 224 X 10 litres (Franks, 1983 Nicholson, 1985). 

The GWC sink for C02 may increase with intensification of the hydrologic cycle (Huntington 2006), including increase in MP DIC (increase in atmosphere pC02 and carbonate dust) and in RO DIC (due to reforestation Liu Zhao 2000). 

Hydrological cycle The cyclic transfer of water vapor from the Earth s surface via evapotranspiration into the atmosphere, from the atmosphere via precipitation back to earth, and through runoff into streams, rivers, and lakes, and ultimately into the oceans (U.S. Geological Survey, 2003). 

See also Hydrologic cycle chemical weathering in, 26 4-7 coupling of atmosphere, land, and water in, 26 7-12... 

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... 

The warming climate is likely to induce changes in the hydrological cycle that will lead to further climate change. Increased heating should increase the rate of evaporation and, hence, the amount of water vapor, which is a GHG. The IPCC s Fourth Assessment Report, published in 2007, finds that the average atmospheric water vapor content has increased since at least the 1980s over land and ocean as well as in the upper troposphere. ... 

In the preceding chapters, we have discussed the ocean s pivotal role in the crustal-ocean-atmosphere fectory. For example, the ocean serves as a receptacle for chemical flows originating from land. We have seen that the ocean s ability to either store these chemicals or bury them in the sediments is a crucial component of the global biogeo-chemical cycles that influence climate and, hence, the hydrological cycle and ocean circulation. These and other linkages support feedbacks that act on biological diversity and abundance, terrestrial erosion, and atmospheric composition. 

Hydrological cycle The global water cycle involving the transport of this substance between the atmosphere, hydrosphere, and lithosphere. 

The hydrologic cycle. Water evaporated at Earths surface enters the atmosphere as water vapor, condenses into clouds, precipitates as rain or snow, and falls back to the surface, only to go through the cycle yet another time. 

Thus, the problem of assessing the role of precipitation in leaching C02 from the atmosphere is urgent, and to solve it the global model should separately take into account the change in hydrological cycles over the World Ocean and over land, since these regions of the planet dilfer in their interaction with the atmosphere. 

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