751 articles
Epilimnion
The epilimnion is the warm, well-mixed upper layer of a stratified lake, holding the warmest water and mixed by wind, typically 10 to 40 feet thick.
Epilithon
Epilithon is the community of algae, bacteria, fungi, and protozoa that grows attached to rocks and stones in streams and lakes, forming the familiar slimy biofilm.
Equatorial undercurrent
The equatorial undercurrent is a narrow subsurface ocean current flowing eastward along the Equator in the Pacific, Atlantic, and Indian Oceans, against the trade winds, about 100 meters deep in the Pacific.
Equatorial upwelling
Equatorial upwelling is the rising of cold, nutrient-rich subsurface water to the ocean surface along the equator, driven by trade winds through Ekman transport and supporting major fisheries.
Eric A. D’Asaro
Eric A. D'Asaro is an American physical oceanographer at the University of Washington's Applied Physics Laboratory who developed the Lagrangian float and was elected to the National Academy of Sciences in 2014.
Erosion control
Erosion control is the practice of preventing or reducing the wearing away of land by water, wind, and related processes, applied on farmland, construction sites, forests, and streambanks.
Euphotic zone
The euphotic zone is the sunlit upper ocean layer where 1 percent of surface light still penetrates, allowing photosynthesis and nearly all marine primary production, typically 40 to 200 meters deep.
Euro-Argo
Euro-Argo is the European Research Infrastructure Consortium, created in 2014, that coordinates Europe's contribution to Argo, the global array of profiling floats measuring ocean temperature and salinity.
European Flood Awareness System
The European Flood Awareness System (EFAS) is a Copernicus flood forecasting system covering Europe, developed after the 2002 central European floods and operational since 2012.
Eutrophication
Eutrophication, also spelled eutrofication, is the overenrichment of a water body with nutrients, mainly nitrogen and phosphorus from fertilizer runoff and sewage, causing algal blooms, oxygen depletion, and biodiversity loss.
Evapotranspiration
Evapotranspiration is the combined transfer of water vapor to the atmosphere by evaporation from soil and water surfaces and transpiration through plants, key to irrigation and drought planning.
Exopolymeric substances
Exopolymeric substances (EPS) are organic polymers, mostly polysaccharides and proteins, excreted by microbes such as bacteria and phytoplankton, binding marine snow aggregates and driving biofilm fouling.
Experimental Lakes Area
The Experimental Lakes Area is a research region of 58 small lakes in northwestern Ontario, Canada, set aside in 1968, where scientists manipulate entire lake ecosystems to study pollution.
Export production
Export production (EP) is the organic carbon produced in the ocean's sunlit surface layer that sinks toward the deep ocean, linking photosynthesis to the biological carbon pump.
f-ratio (oceanography)
The f-ratio is a dimensionless index in biological oceanography, the fraction of phytoplankton production fueled by nitrate rather than recycled ammonium, introduced by Dugdale and Goering in 1967.
Fast ice
Fast ice, also called landfast ice, is sea ice fixed along the coast to shore, shoals, or grounded icebergs, covering about 1.8 million km² of the Arctic in winter.
Fecal pellet
In oceanography, a fecal pellet is a compacted package of organic waste egested by zooplankton or fish, and a major vehicle of the biological carbon pump.
Fetch (oceanography)
Fetch, in oceanography, is the area of open water over which wind blows in a roughly constant direction and generates waves, determining wave size alongside wind speed and duration.
Field capacity
Field capacity is the water content retained in soil after saturation, once excess water has drained under gravity; introduced in 1931, it remains standard in irrigation and hydrologic modeling.
Fine particulate organic matter
Fine particulate organic matter (FPOM) is the organic fraction of particles between 0.45 and 1000 μm in streams and rivers, and a key food for collector invertebrates.
Fingering instability
Fingering instability, also called wetting front instability, is the breakup of a planar wetting front into narrow wetting fingers during infiltration into unsaturated soil, which speeds water and solute movement to groundwater.
Flash flood
A flash flood is a flood of short duration and high peak discharge that rises rapidly, usually within six hours of intense rainfall or a dam failure.
Fleet Numerical Meteorology and Oceanography Center
The Fleet Numerical Meteorology and Oceanography Center (FNMOC) is the United States Navy's operational numerical weather prediction center, dual-located in Monterey, California, and Stennis Space Center, Mississippi.
Fleet Survey Team (United States Navy)
The Fleet Survey Team is a deployable U.S. Navy hydrographic unit, commissioned in 2005 under the Naval Oceanographic Office, that surveys littoral waters, ports, and landing beaches.
Float (oceanography)
In oceanography, a float is an autonomous free-drifting instrument that sinks to a set depth and profiles temperature and salinity, transmitting data by satellite when it surfaces; about 4,000 are operated by the international Argo program.
Floating island
A floating island is a buoyant mass of vegetation, peat, or other material resting on a lake's surface, occurring naturally in wetlands and built deliberately for water treatment.
Flood
A flood is an excess of water on normally dry land, caused by overflowing rivers, heavy rain, snowmelt, or dam failure, and is the most common weather-related disaster.
Flood frequency analysis
Flood frequency analysis is a statistical method relating flood magnitude at a river or coastal site to its annual exceedance probability, used in drainage design and dam safety.
Flood inundation mapping
Flood inundation mapping is the geospatial technique that maps the extent and depth of floodwater, using hydraulic models, satellite imagery, or terrain analysis, producing extent maps and depth grids.
Flood pulse
The flood pulse is the periodic inundation and drying of a river's floodplain. The 1989 Flood Pulse Concept by Junk, Bayley, and Sparks holds it drives river-floodplain productivity.