RAPID Climate Change (RAPID) array

RAPID Climate Change (RAPID) array
Name	RAPID Climate Change (RAPID) array
Country	United Kingdom
Institution	National Oceanography Centre
Established	2004

RAPID Climate Change (RAPID) array is a sustained oceanographic observing system designed to monitor the strength and variability of the Atlantic Meridional Overturning Circulation. The array links long-term climate observing efforts with process studies and climate modeling communities across institutions such as the National Oceanography Centre, University of Southampton, Woods Hole Oceanographic Institution, Scripps Institution of Oceanography and agencies including the Natural Environment Research Council, National Oceanic and Atmospheric Administration, European Commission, and National Science Foundation. Its work interfaces with major programs and assessments like the Intergovernmental Panel on Climate Change, World Climate Research Programme, United Nations Framework Convention on Climate Change, Global Ocean Observing System, and regional initiatives such as UK Research and Innovation-funded projects.

Overview

RAPID was conceived following recommendations emerging from workshops involving James Hansen, Sir John Houghton, Gavin Schmidt, and contributors to Climate Change 2001 and Climate Change 2007 assessment cycles, aiming to provide continuous estimates of the strength of the Atlantic Meridional Overturning Circulation. The array occupies a zonal section at 26°N across the North Atlantic between Bermuda, Canary Islands, Azores, and Florida, combining moorings, current meters, pressure sensors, and hydrographic surveys in collaboration with institutions such as University of Oxford, University of Cambridge, Imperial College London, Princeton University, and University of Miami. The program builds on earlier observational work like the Atlantic Meridional Overturning Circulation (AMOC) concept, the Gulf Stream studies, and the Deutsche Forschungsgemeinschaft-supported transatlantic projects.

Objectives and Scientific Goals

The primary objective is to provide continuous, high-quality time series of the strength, transport, and variability of the Atlantic Meridional Overturning Circulation to inform detection and attribution studies used by Intergovernmental Panel on Climate Change reports and national assessments such as those by Met Office Hadley Centre and NOAA Climate Program Office. Secondary goals include constraining climate model biases in ensembles from centers like European Centre for Medium-Range Weather Forecasts, NCAR, GFDL, EC-Earth, and HadGEM3, improving projections used by IPCC scenarios and Coupled Model Intercomparison Project participants, and informing process studies conducted by groups at Lamont–Doherty Earth Observatory, Plymouth Marine Laboratory, and GEOMAR.

Instrumentation and Array Design

The array integrates moored instrumentation including bottom pressure recorders, acoustic Doppler current profilers, thermistor chains, and kalman-filtered current meters from manufacturers and platforms used by Ocean Observatories Initiative, Argo, SeaWiFS, and Jason (satellite). It uses boundary-focused design principles inspired by work at Woods Hole Oceanographic Institution and methodologies from Sverdrup-related circulation theory, combining western and eastern boundary arrays, mid-basin sensors, and cross-basin hydrographic sections carried out by research vessels like RRS James Cook, RV Atlantic Explorer, RV Knorr, and ships operated by Monterey Bay Aquarium Research Institute. The design leverages long-term instrumentation standards from Coriolis and partnerships with British Antarctic Survey for logistical support.

Deployment and Operations

Deployments are executed via coordinated cruises and ship-of-opportunity efforts involving fleets coordinated with organizations such as International Council for the Exploration of the Sea, European Marine Observation and Data Network, and national navies when required. Operations include seasonal maintenance, recovery, and redeployment cycles, and collaborations with research programs like GEOTRACES, GO-SHIP, Pelagic Inshore Fisheries Institute and regional observing systems at Bermuda Institute of Ocean Sciences. Data from moorings, hydrographic casts, and autonomous platforms are quality-controlled by teams at the National Oceanography Centre, University of Southampton, and partners including Scripps Institution of Oceanography.

Key Findings and Scientific Contributions

RAPID has produced continuous AMOC time series revealing substantial variability on seasonal to decadal timescales, documenting events explored in syntheses by Intergovernmental Panel on Climate Change authors and compared with reconstructions from proxy studies involving European Project for Ice Coring in Antarctica, North Atlantic Oscillation, Atlantic Multidecadal Variability, and paleoceanographic records from International Ocean Discovery Program cores. Results have informed understanding of heat and freshwater transports relevant to impacts studied by Met Office Hadley Centre, NOAA, NASA, European Commission-funded climate services, and national adaptation planning in regions including United Kingdom, United States, Portugal, and Spain. RAPID findings have been integrated into model evaluation activities at Princeton University, University of Colorado Boulder, NOAA Geophysical Fluid Dynamics Laboratory, and international model intercomparison projects.

Data Management and Accessibility

Data stewardship follows community best practices coordinated with repositories and standards promoted by Global Ocean Observing System, PANGAEA (data publisher), British Oceanographic Data Centre, National Centers for Environmental Information, and EMODnet. Time series, calibrated mooring data, and derived transports are made available to researchers and stakeholders through curated portals managed by the National Oceanography Centre and partner institutions, supporting analyses by scientists at Scripps Institution of Oceanography, Lamont–Doherty Earth Observatory, WHOI, and modeling centers including ECMWF and NCAR. Metadata, processing codes, and synthesis products are routinely cited in assessments by IPCC authors and national reports.

Challenges and Future Directions

Operational challenges include sustainment of long-term funding from agencies such as Natural Environment Research Council, National Science Foundation, and European Commission, technological issues with deep-water telemetry, and integration with expanding autonomous observing systems like Argo, Bio-Argo, and glider networks developed by Monterey Bay Aquarium Research Institute and IFREMER. Future directions emphasize enhanced spatial coverage, synergies with satellite missions by European Space Agency and NASA, deeper coupling to Earth system models used at GFDL and UK Met Office Hadley Centre, and integration with policy-relevant assessments undertaken by Intergovernmental Panel on Climate Change and national climate services to improve predictions of climate impacts for countries bordering the North Atlantic.

Category:Oceanography Category:Climate monitoring