751 articles
Calcium carbonate saturation horizon
The calcium carbonate saturation horizon is the ocean depth where seawater is exactly saturated with calcium carbonate, with separate horizons for calcite and the more soluble aragonite.
Canadian Hydrographic Service
The Canadian Hydrographic Service (CHS) is Canada's hydrographic office, a Fisheries and Oceans Canada division founded in 1883 that surveys Canadian waters and produces official nautical charts, tide tables, and sailing directions.
Canadian Meteorological and Oceanographic Society
The Canadian Meteorological and Oceanographic Society, also known as CMOS, is Canada's national society advancing atmospheric and oceanic sciences, founded in 1967 and based in Ottawa.
Canary Current
The Canary Current is a wind-driven eastern boundary current flowing southward along northwest Africa and Iberia, driving one of the world's four major coastal upwelling systems.
Canopy cover
Canopy cover is the proportion of ground or stream surface covered by the vertical projection of vegetation canopies, a standard metric in forestry and stream monitoring.
Canopy interception
Canopy interception is the capture and temporary retention of precipitation by a vegetation canopy, typically 10% to 30% of gross rainfall, evaporating or reaching the ground as throughfall or stemflow.
Carbonate compensation depth
The carbonate compensation depth (CCD) is the ocean depth at which the supply of calcium carbonate sinking from the surface equals its dissolution at the seafloor.
Ceriodaphnia
Ceriodaphnia is a genus of small freshwater water fleas in the family Daphniidae, whose species Ceriodaphnia dubia is a standard organism in regulatory aquatic toxicity testing.
Challenger expedition
The Challenger expedition was a British scientific voyage around the globe aboard HMS Challenger from 1872 to 1876, regarded as the founding voyage of modern oceanography.
Chalybeate
Chalybeate, also called chalybeate water, is mineral spring water containing dissolved iron salts, typically reduced iron Fe(II), giving it a metallic taste and reddish-brown color.
Changes in the course of the Yellow River
The changes in the course of the Yellow River, or Huang He, are repeated shifts of the lower river across the North China Plain, about 26 significant changes recorded since the Qin Dynasty.
Channel incision
Channel incision is the downward erosion of a stream bed that lowers the channel relative to its floodplain, occurring when sediment removed exceeds sediment supplied.
Charcoal analysis of lake sediments
Charcoal analysis of lake sediments is a paleoecological method that counts and dates charcoal preserved in lake-bottom mud to reconstruct fire frequency and biomass burning over millennia.
Chart datum
Chart datum, also called tidal datum, is the low vertical reference plane to which nautical chart depths and tide predictions are referred, set so water seldom falls below it.
Chemosynthetic ecosystems
Chemosynthetic ecosystems are biological communities whose food supply comes from chemical energy instead of sunlight, first discovered at hydrothermal vents near the Galapagos Islands in 1977.
Chikyu (drillship)
Chikyu (ちきゅう, "Earth") is a Japanese deep-sea scientific drillship operated by JAMSTEC, delivered in 2005, the only scientific drillship with riser drilling, built to drill toward Earth's upper mantle.
Chloride mass balance
The chloride mass balance (CMB) is a hydrogeological method for estimating groundwater recharge by comparing chloride deposited in precipitation with chloride concentrations in groundwater or unsaturated-zone water.
Chlorophyll maximum
A chlorophyll maximum, also called the deep chlorophyll maximum (DCM) or subsurface chlorophyll maximum, is a layer in stratified lakes and oceans where chlorophyll-a peaks below the surface, often accounting for much of primary production.
CLIVAR
CLIVAR (Climate and Ocean: Variability, Predictability and Change) is a core project of the World Climate Research Programme, launched in 1995 to study the ocean's role in climate.
Coarse particulate organic matter
Coarse particulate organic matter (CPOM) is the fraction of aquatic detritus larger than 1 mm, chiefly terrestrial leaves, twigs, and wood entering streams from the riparian zone.
Coastal boundary layer
The coastal boundary layer (CBL) is the inshore region of a large lake or coastal ocean where the shore shapes currents, mixing, and transport, also called the inner shelf.
Coastal flooding
Coastal flooding, also called coastal inundation or estuarine flooding, is the flooding of low-lying land by seawater, most often when storm surges and strong winds coincide with high tides.
Coastal upwelling
Coastal upwelling is the wind-driven rise of cold, nutrient-rich deep water along coastlines, where winds push surface water offshore and it is replaced from below.
Coastal Zone Color Scanner
The Coastal Zone Color Scanner (CZCS) was a NASA radiometer on the Nimbus-7 satellite, launched in 1978, that was the first sensor devoted to measuring ocean color from space.
Cold blob
The cold blob, also called the North Atlantic warming hole, is a region south of Greenland where sea surface temperatures have cooled even as the rest of the planet warmed.
Cold seep
A cold seep, also called a methane seep, is a seafloor location where methane-rich fluids escape into the ocean at temperatures near that of seawater, sustaining ecosystems that live without sunlight.
Compass rose
A compass rose, also called a rose of the winds, is a circular symbol on maps and nautical charts showing direction, graduated in degrees from 0° to 360°.
Conduit flow
Conduit flow is groundwater movement through solution-enlarged conduits in karst aquifers such as limestone and gypsum; conduits form as acidic water dissolves fractures, then dominate the aquifer's hydraulics despite occupying little of its storage.
Cone of depression
A cone of depression is the cone-shaped lowering of the water table around a pumping well, first given a mathematical treatment by Charles V. Theis in 1935.
Confined aquifer
A confined aquifer is a water-bearing layer sealed between impermeable rock, holding groundwater under pressure; a well drilled into it can flow at the surface without pumping.