User:Stans068/Limnology

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The study of inland waters, such as lakes, reservoirs, rivers, ponds, and swamps is known as limnology. In 1949, Edgardio Baldi defined it as "the study of the interrelated processes and methods by which matter and energy are transformed in a lake." So they are saying it's the study of the exchange of energy within lake ecosystems whether that be with the Sun or the other nutrients present in aquatic areas. Each water source is an ecosystem of it's own, consisting of energy flow and matter cycling. An ecosystem is a dynamic unit of nature made of both biotic (living) and abiotic (non-living) factors.

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History

Several hundred years ago, the discipline of limnology was understood as the physical geography of lakes and that the biological processes going on in freshwater was a separate area of study. In 1927, Norway's Kaare Knutsson Münster Strøm was a limnologist that, during his presentation at Cambridge University, declared the subject of limnology as the study of all aspects of fresh water, both flowing and still, including their geography, physical properties, chemistry, biology and geology of the foundations and watersheds. They emphasized the importance of the subject at that time with it's relation to fishing industries and the potential economic concern that could arise if freshwater sources were contaminated, killing the fish that could be used for profits. The importance of human health was touched on as a subfield dealing with hygiene, including the highly important concerns of water sources and sewage disposal within lake areas. America and Europe differed with their understandings such that America from the beginning was focused on the chemical cycles in a system while Europe focused on the study of communities.

General Properties

Water

Water is unevenly distributed around the world. A reserve of inland waters, including ground water, determines the availability of liquid water. Evaporation, wind transportation, precipitation, and drainage make up the hydrologic cycle. The continual change from the liquid phase in the oceans to the gaseous phase in the atmosphere to precipitation over the continents drives the cycle, which is powered by solar radiation and wind energy.

One of the best known solvents, water can dissolve both ions and gas. By dissolving the ions from rocks, water's properties as a solvent have significantly altered the geological weathering of the earth's surface.

Water has a high heat capacity, which indicates that raising the temperature of liquid water requires a significant amount of energy. Aquatic species remain protected from sudden temperature fluctuations by the water's ability to act as a buffer.

The volume and quality of water in underground aquifers rely on the vegetation cover, which fosters recharge and aids in maintaining water quality.

Thermal Stratification

Solar radiation that reaches the water's surface is the primary source of heat or thermal energy. Interlocking effects of heat exchange and solar radiation intake lead to the stratification and mixing processes. The thermal stratification means lighter water with a warmer temperature lays on its surface while cooler, more dense water is layered below. The vertical gradient established is the result of thermal cooling mechanisms. Pressure, which reduces the temperature of maximum density, and the presence of dissolved compounds are both factors that can change the density of water and vertical gradients. The buoyancy frequency is used to identify different vertical gradients.

Light Interactions

When light reaches the water surface, it can either be reflected or penetrate the water. In terrestrial and aquatic ecosystems, only a fraction of the solar radiation that reaches the surface may be absorbed for photosynthesis. Latitude, season, day, and cloud cover all affect how much radiation reaches the surface of lakes, oceans, and continents. The layer of a body of water that is visible is called the euphotic zone. In the first few meters of the subsurface, the water column quickly absorbs solar and UV light that is present in the infrared spectrum. The aphotic zone is the remainder of the water column, which is deeper and does not receive enough natural light to support plant growth. The amount of solar energy present underwater and the spectral quality of the light that are present at various depths have a significant impact on the behavior of many aquatic organisms. For example, zooplankton's vertical migration is influenced by solar energy levels. Light intensity drops logarithmically with depth in a water column. Ecosystems would not be able to exchange energy without light, and the majority of biogeochemical cycles would collapse.

Chemistry

Given that there are so many dissolved ions and organic materials, the chemical composition of naturally occurring inland waters is complex. The elements and substances are sourced from the environment, human activity, and the atmosphere. The geochemistry of the soil and rocks that form the foundation of water basins causes significant chemical impacts.

Conductivity is defined as the sum of all ions or the sum of all materials dissolved in water. The relative ability of water to conduct electricity is known as conductivity.

Intermolecular distances are impacted by temperature changes. The molecular structure's empty gaps are filled in when ice melts, increasing the density of the resulting water. Due to longer intermolecular distances and a lower density, liquids expand as temperature rises.

Materials in aquatic systems are balanced by organisms' activities like respiration and excretion.