Description
Presentations on Roadmap for future AMOC observing
Progress in information technology has driven exponential growth in the number of global ocean observations and the fidelity of numerical simulations of the ocean in the past few decades. The growth has been exponentially faster for ocean simulations, however. The present cutting-edge ocean circulation models running on the latest supercomputers can cover the globe with resolutions of a few...
Nature runs are state-of-the-art numerical simulations that are as close as possible to reality that can be used as reference for design of observational arrays and/or data assimilation. We will review the current status of basin-scale to global-scale AMOC modeling and define the minimum requirements that a numerical model should be able to reproduce (mean transport and water mass...
The Overturning in the Subpolar North Atlantic Program (OSNAP) array, consisting of an OSNAP West section covering the Labrador Sea and an OSNAP East section covering the Irminger and Iceland basins, has continuously observed the MOC and meridional heat and freshwater transports (MHT and MFT, respectively) since 2014. The OSNAP observations have contributed substantially to the understanding...
Based on geostrophy, the zonally-integrated mass transport at a given depth is simply the difference between the pressure on the boundaries at that depth. Thus, to measure the overturning streamfunction, in depth space, only measurements of pressure are theoretically required. Presently, only high-frequency pressure anomalies can be reliably measured directly at constant depth in the ocean....
The Atlantic Meridional Overturning Circulation, a crucial element of the Earths’ climate system, is projected to weaken over the course of the 21st Century which could have far reaching consequences for the occurrence of extreme weather events, sea level rise, monsoon regions and the marine ecosystem. The latest IPCC puts the likelihood of such a weakening as “very likely”. As our confidence...
The North Atlantic Ocean circulation is the result of a range of physical processes, from large-scale gyre circulation (subtropical and subpolar), associated Ekman transports, fluctuations of the gyre boundaries, westward intensification that gives rise to the Gulf Stream, watermass transformation at high latitudes along continental boundaries and in the interior, complex ("return") flows at...
The subpolar North Atlantic plays an important role in connecting the upper and the lower branches of the Atlantic Meridional Overturning Circulation. The Labrador Sea is part of this system. By means of repeat hydrographic sections and a mooring array, the Deep Western Boundary Current (DWBC) system is measured at the southern exit of the Labrador Sea with help of the 53°N Observatory since...
The Atlantic Meridional Overturning Circulation (AMOC) plays a vital role in the climate system of Europe and the Arctic by redistributing heat and freshwater in the Atlantic. Since climate model studies project a decline of the AMOC in the 21st century, monitoring AMOC changes remains essential. While on longer than decadal timescales AMOC variability is expected to be coherent across...
This presentation will be a tale of two perspectives that come together to inform AMOC observing needs in a changing climate. First, I will share some results from NASA’s gravity and altimetry satellite science teams that highlight how these NASA assets contribute to monitoring and understanding AMOC. Second, I will present highlights from my own analysis of future Earth system simulations, in...
A large ensemble of adjoint-based sensitivity experiments within the Arctic and Subpolar gyre sTate Estimate (ASTE) is used to interrogate the constraint provided by continuous monitoring at the Overturning in the Subpolar North Atlantic Program (OSNAP) array. Each ensemble member is designed to expose ocean adjustments impacting the hydrography sampled at an individual mooring within the...
