751 articles
Rock flour
Rock flour, also called glacial flour or glacier milk (French farine glaciaire), is fine silt-size sediment produced by glaciers grinding bedrock, which turns meltwater streams milky white.
Rogue wave
A rogue wave, also called a freak wave, is an unusually large ocean surface wave, more than twice the height of the surrounding sea state.
Rosette sampler
A rosette sampler is an oceanographic water-sampling device with 12 to 36 bottles around a CTD sensor package, lowered from a ship to profile the water column.
Rossby wave
A Rossby wave, also called a planetary wave, is a large-scale westward-propagating oscillation in rotating fluids like Earth's ocean and atmosphere, predicted by meteorologist Carl-Gustaf Rossby in the 1930s.
RP FLIP
RP FLIP, or FLoating Instrument Platform, was a Scripps Institution spar buoy that flipped upright at sea to serve as a stable research lab from 1962 to 2023.
RRS Sir David Attenborough
RRS Sir David Attenborough is a British polar research and supply ship of the British Antarctic Survey, delivered in 2020 after a naming poll won by "Boaty McBoatface".
Runoff coefficient
The runoff coefficient (C) is a dimensionless number expressing what fraction of rainfall becomes direct runoff, most familiar from the Rational Method for estimating peak discharge.
Runoff curve number
The runoff curve number, or curve number, is an empirical index, developed in 1954 by the USDA Soil Conservation Service, that converts soil and land cover into storm runoff estimates.
Runoff generation
Runoff generation is the set of physical processes turning precipitation into streamflow, conventionally distinguished as infiltration-excess overland flow, saturation-excess overland flow, subsurface stormflow, and groundwater flow.
Runoff model (reservoir)
A runoff model (reservoir) is a rainfall-runoff model representing a catchment as storage reservoirs that delay and release water, as in the linear reservoir, Nash cascade, and Tank model.
Russian Hydrographic Service
The Hydrographic Service of the Russian Navy is the state body for nautical charting and hydrographic surveying, administered by the Ministry of Defense's Navigation and Oceanography Department.
RV Atlantis (research vessel)
RV Atlantis is a U.S. Navy-owned oceanographic research vessel operated by Woods Hole Oceanographic Institution since 1997 and built to launch and service the Alvin submersible.
RV Petrel
RV Petrel, now MV Sarah Lynn, is a research vessel that found famous lost World War II warships, including USS Indianapolis, and was bought by the US Navy in 2022.
RV Sikuliaq
RV Sikuliaq, named for an Iñupiaq word meaning young sea ice, is a 261-foot research vessel operated by the University of Alaska Fairbanks in Seward, Alaska.
RV Thomas G. Thompson (T-AGOR-23)
R/V Thomas G. Thompson (T-AGOR-23) is a Navy-owned Global-class oceanographic research vessel operated by the University of Washington's School of Oceanography, built in 1991 and home-ported in Seattle.
S-100 (IHO standard)
S-100 is the International Hydrographic Organization's Universal Hydrographic Data Model, a framework of standards for managing and exchanging digital hydrographic data, replacing the older S-57 standard.
S-100 Universal Hydrographic Data Model
S-100 is the International Hydrographic Organization's universal hydrographic data model, an 18-part framework based on ISO 19100 that underpins S-10x products like the S-101 chart.
S-57 (hydrographic data standard)
S-57 is the International Hydrographic Organization's transfer standard for digital hydrographic data, used to exchange data between hydrographic offices and build Electronic Navigational Charts for ECDIS.
Saildrone
Saildrone is a family of wind- and solar-powered robotic sailboats built by Saildrone, Inc. of Alameda, California, used for ocean science, hurricane research, and maritime security.
Sailing Directions
Sailing Directions are official descriptive pilotage publications issued by national hydrographic offices, providing written coastal, port-approach, and passage-planning information to supplement nautical charts; main producers include NGA, NOAA, and the UK Hydrographic Office.
Salinas River (California)
The Salinas River is the longest river of California's central coast, flowing about 152 miles through the Salinas Valley to Monterey Bay and recharging the aquifer beneath one of America's most productive farm regions.
Saline water
Saline water, also known as salt water, contains dissolved salts, mostly sodium chloride, in amounts too high for drinking or irrigation; ocean water is about 3.5 percent salt.
Salinity
Salinity is the content of dissolved salts in seawater, historically in grams per kilogram and today measured through conductivity-based scales; full-strength seawater sits at about 35.
Salinometer
A salinometer is an instrument that determines the salinity of a water sample by measuring its electrical conductivity, used widely in oceanography and in marine engineering.
Salt lake
A salt lake, also called a saline or brine lake, is a closed-basin lake whose water exceeds about 3 g/L dissolved salt, typically forming in arid basins where evaporation concentrates minerals.
Saraswati River
The Saraswati River (Sanskrit: Sarasvati) is a lost river of northwest India praised in the Rigveda and identified with the Ghaggar-Hakra system, whose dry bed runs through Punjab, Haryana, and Rajasthan.
Satellite altimetry
Satellite altimetry is a remote-sensing technique that measures sea surface height, ice, and inland waters by timing radar or laser pulses, supporting sea level monitoring since 1973.
Satellite remote sensing of the ocean
Satellite remote sensing of the ocean is the measurement of sea surface properties from orbit using electromagnetic sensors instead of ships and buoys, observing sea level, winds, temperature, ice, and color.
Satellite-derived bathymetry
Satellite-derived bathymetry (SDB) is the calculation of shallow water depth from satellite sensors, a low-cost remote alternative to surveys in inaccessible areas, formally guided by the IHO since 2024.
Scatterometer
A scatterometer is a radar instrument that measures ocean surface wind speed and direction from the backscatter of microwave pulses, first demonstrated on Skylab in 1973.