drifters (oceanography)

drifters (oceanography)
Name	Drifters
Classification	Surface oceanographic instruments

Contents

drifters (oceanography) Drifters are free-floating surface instruments used to measure currents, temperature, salinity, and other oceanographic variables. They provide Lagrangian observations that complement Eulerian measurements from buoys, satellites, and ships, and are widely used in studies by organizations such as National Oceanic and Atmospheric Administration, Scripps Institution of Oceanography, Woods Hole Oceanographic Institution, and Plymouth Marine Laboratory. Drifters support operational systems in contexts linked to NOAA National Weather Service, European Space Agency, and research programmes like Argo (oceanography), Global Drifter Program, and World Ocean Circulation Experiment.

Introduction

Drifters operate by following water parcels to sample surface and near-surface properties, informing understanding of phenomena from mesoscale eddies to basin-scale circulations. They are deployed in regions investigated by expeditions such as HMS Challenger expedition and programmes associated with institutions like Lamont–Doherty Earth Observatory, Bermuda Institute of Ocean Sciences, and Monterey Bay Aquarium Research Institute. Data from drifters feed into assimilation frameworks used by centers including European Centre for Medium-Range Weather Forecasts, National Centers for Environmental Prediction, and projects like Copernicus Programme.

Drifter designs vary to target specific layers and processes. Surface drifters often use drogues or sea anchors designed by groups at Scripps Institution of Oceanography and Woods Hole Oceanographic Institution to minimize wind slip, inspired by early devices from Benjamin Franklin experiments and later refined in studies by Walter Munk and Maurice Ewing. Subsurface variants include isopycnal drifters influenced by concepts used in Argo (oceanography) profiling floats and by technologies developed at IFREMER and Japan Agency for Marine-Earth Science and Technology. Specialized types include SVP (Surface Velocity Program) drifters promoted by the Global Drifter Program, coastal drifters used by National Oceanography Centre (UK), oil-spill tracking drifters applied in response efforts by United States Coast Guard, and biodegradable prototypes trialed in collaborations with Ocean Conservancy and The Ocean Cleanup. Components such as GPS receivers, satellite transmitters from providers like Iridium Communications and Argos (satellite system), drogues modeled after work at Scripps Institution of Oceanography, and sensors supplied by manufacturers with ties to Teledyne Technologies determine capabilities and costs.

Deployments occur from platforms including research vessels like RV Knorr, RRS Discovery (1962), and commercial ships participating in Ship of Opportunity Programme, as well as from aircraft operated by agencies like United States Navy and Royal Navy (United Kingdom). Deployment campaigns are coordinated with institutions such as Global Drifter Program, National Oceanic and Atmospheric Administration, and regional programmes under Regional Seas Programme frameworks supported by United Nations Environment Programme. Operations involve mission planning, real-time telemetry through satellites like GOES and MetOp, and data management within archives maintained by National Centers for Environmental Information and PANGAEA (data repository). Fieldwork methodology draws on practices from landmark cruises led by scientists at Scripps Institution of Oceanography, Lamont–Doherty Earth Observatory, and Woods Hole Oceanographic Institution.

Drifter datasets contribute to oceanographic research, climate studies, and operational forecasting. Outputs inform analyses by groups including National Aeronautics and Space Administration, European Organisation for the Exploitation of Meteorological Satellites, and research carried out by universities such as Massachusetts Institute of Technology, University of Oxford, University of Cambridge, and University of Tokyo. Applications encompass validation of satellite missions like TOPEX/Poseidon, Jason-1, and Sentinel-3 (satellite), improvement of circulation models developed at NOAA Geophysical Fluid Dynamics Laboratory and Met Office Hadley Centre, and ecological studies in collaboration with institutions such as Smithsonian Institution and Woods Hole Oceanographic Institution. Drifter data underpin emergency response to spills referenced by Exxon Valdez oil spill research, marine debris tracking tied to events like 2011 Tōhoku earthquake and tsunami, and search-and-rescue optimization practiced by United States Coast Guard.

Drifter observations are subject to errors from wind-induced slip, biofouling, sensor drift, and drogue loss noted in analyses by National Oceanic and Atmospheric Administration and laboratories at Scripps Institution of Oceanography. Sampling biases arise from uneven spatial coverage influenced by trading routes utilized in Ship of Opportunity Programme and deployment priorities of programmes like Global Drifter Program. Data quality control protocols developed by Global Ocean Observing System and International Oceanographic Commission address calibration challenges, whereas assimilation into models must account for representativeness errors examined in studies at European Centre for Medium-Range Weather Forecasts and NOAA Geophysical Fluid Dynamics Laboratory.

The lineage of drifters traces to early surface current observations during expeditions such as HMS Challenger expedition and to practical innovations by investigators like Benjamin Franklin and later oceanographers including Walter Munk and Henry Stommel. Major coordinated efforts include the Global Drifter Program, initiated with support from National Oceanic and Atmospheric Administration and NASA, and basin-scale deployments during the World Ocean Circulation Experiment. Notable projects employing drifters span collaborations among Scripps Institution of Oceanography, Woods Hole Oceanographic Institution, Lamont–Doherty Earth Observatory, IFREMER, Japan Agency for Marine-Earth Science and Technology, and international consortia participating in initiatives tied to UN Decade of Ocean Science for Sustainable Development.

Category:Oceanographic instruments