NSF Award
2334091
This is a project jointly funded by the National Science Foundation’s Directorate for Geosciences (NSF/GEO) and the National Environment Research Council (NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award recommendation, each Agency funds the proportion of the budget that supports scientists at institutions in their respective countries. The global climate system is rapidly changing under anthropogenic greenhouse gas emissions, and a major mechanism of climate change associated with profound environmental, social and economic impacts is the meridional overturning circulation in the Atlantic Ocean (AMOC). AMOC transports heat through the Atlantic, and climate and weather on the surrounding continents is sensitive to its mean state and variability. Furthermore, AMOC exerts significant control on the ocean’s sequestration of anthropogenic carbon. IPCC projections have a declining AMOC over the next century, but at present the only way to know the state of the AMOC, and to assess the validity of climate models, is by observing it with moored arrays of which there are very few. Since 2004 the UK and US have worked in partnership to implement the 26°N RAPID-MOCHA array. The array is simple in design but heavily dependent on research vessels. Recent developments in observing technology and process understanding provide an opportunity to test new approaches to observing the Atlantic Meridional Overturning Circulation (AMOC). This project will design and test lower-cost, sustainable observing systems to provide AMOC estimates at the accuracy and frequency required by users. Target stakeholders are researchers, forecasters, and decision-makers planning for the effects of climate change. The program will be delivered in a partnership between UK (NOC, Met Office) and US (University of Miami and NOAA Atlantic Oceanographic and Meteorological Laboratory).<br/><br/>This particular component of the program will provide glider measurements of temperature, salinity and currents from ADCP, which will be used to test the step method for deriving the wester boundary overturning transport from ocean bottom pressure gradients. The higher density of measurements from the glider will allow for better testing of this approach than can be done from the moorings alone. Glider sections will cover the entire 0-1000m zonal section spanning from the Bahamas shore to 40 km offshore where the abyssal plain starts. The meridional component of direct ADCP velocity measurements will be validated by the estimates of velocity that will be obtained from the density section through a geostrophic calculation and by comparison with the moored current meter data.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
