The water cycle, or hydrologic cycle, is the continuous circulation of water within the Earth–atmosphere system, driven primarily by solar radiation and gravity. It encompasses phase changes and fluxes such as evaporation and transpiration from surface and biotic reservoirs, condensation in the atmosphere, cloud formation, and subsequent precipitation as rain, snow, or other hydrometeors. Infiltration, percolation, and groundwater flow redistribute water within subsurface reservoirs, while surface runoff and riverine transport return water to oceans and lakes. The water cycle regulates climate, controls energy and mass exchanges, and governs biogeochemical transport across terrestrial, aquatic, and atmospheric compartments.
The small mountain streams that feed many of the West's rivers may face a much drier future. A new study led by NAU researchers found that groundwater-fed streamflow, known as base flow, has been steadily declining across ...
Environment
Aug 2, 2026
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42
Sea-surface salinity, the concentration of dissolved salts in the upper layer of the ocean, is much more than a measure of how salty the sea is. It responds rapidly to changes in rainfall, evaporation, river discharge and, ...
Earth Sciences
Jul 30, 2026
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5
Before rain falls, the moisture that forms it may have traveled anywhere from just a few kilometers to hundreds or even thousands of kilometers away. It usually begins as water that evaporated from oceans, lakes, forests ...
A Florida State University paleoclimatologist led the creation of a global database hosting thousands of seawater isotope measurements collected over almost 50 years that will aid scientists in generating more accurate climate ...
Earth Sciences
Jul 14, 2026
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7
While Reno families were celebrating the 1997 New Year, the Truckee River was surging into the city's downtown streets. A rainstorm was falling on the Sierra Nevada's deep snowpack, melting it rapidly and creating a hazardous ...
Earth Sciences
Jun 16, 2026
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11
Planting trees is widely promoted as a natural solution to climate change. But a new study led by researchers from the Institute of Atmospheric Physics at the Chinese Academy of Sciences finds that the hydrological consequences ...
Earth Sciences
Jun 15, 2026
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62
Nitrate pollution is a growing global environmental challenge due to the extensive use of fertilizer. A study published in Science, led by the Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB) with the Helmholtz ...
Earth Sciences
Jun 12, 2026
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17
Human activities have significantly altered the freshwater cycle, threatening its ability to support vital climatic and ecological Earth system processes. A new study led by researchers at the University of Eastern Finland ...
Earth Sciences
Jun 9, 2026
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61
A collaboration of scientists from NASA and Brazilian research institutions has produced a detailed picture of groundwater change across Brazil. The images reveal significant declines in some of the aquifers that are critical ...
Earth Sciences
Jun 8, 2026
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16
About two-thirds of the U.S. is in some stage of drought in late spring 2026, yet at the same time the country has been seeing more intense downpours. It might seem contradictory, but both are symptoms of rising global temperatures.
Environment
May 26, 2026
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