Mixing and geometry in the North Atlantic Meridional Overturning Circulation

Vertical motions across the ocean are central to processes, like CO2 fixation, heat removal or pollutant transport, which are essential to the Earth's climate. This work explores 3D conveyor routes associated with the Atlantic Meridional Overturning Circulation (AMOC). Our findings show the geometry of mixing structures in the upper and deep ocean layers by means of Lagrangian Coherent Structures. This tool identifies among others, zones linked to vertical transport and characterizes vertical transport time scales. We focus the study in two regions. The first one is the Flemish Cap region, a zone of interaction between the major AMOC components, where our analysis identifies a domain of deep waters that ascend very rapidly to the ocean surface. The second one is the Irminger Sea, where our analysis confirms the existence of a downwelling zone, and reveals a previously unreported upwelling connection between very deep waters and the ocean surface.RB acknowledges support of a CSIC JAE intro fellowship. AMM and GGS acknowledge the support of a CSIC PIE project Ref. 202250E001 and from Grants PID2021-123348OB-I00 funded by MCIN/AEI/10.13039/501100011033/ and by FEDER A way to make Europe. AMM is an active member of the CSIC Interdisciplinary Thematic Platform POLARCSIC and TELEDETECT and acknowledges the support from Grant EIN2020-112235 funded by MCIN/ AEI/10.13039/501100011033/and by the European Union NextGenerationEU/ PRTR. JC also acknowledges the support of the RyC project RYC2018-025169, the Spanish Grant PID2020-114043GB-I00 and PID2021-122954NB-I00 and the “2022 Leonardo Grant for Researchers and Cultural Creators, BBVA Foundation.Peer ReviewedPostprint (published version

Confined rotating convection with large Prandtl number: centrifugal effects on wall modes

Thermal convection in a rotating cylinder with a radius-to-height aspect ratio of G=4 for fluids with large Prandtl number is studied numerically. Centrifugal buoyancy effects are investigated in a regime where the Coriolis force is relatively large and the onset of thermal convection is in the so-called wall modes regime, where pairs of hot and cold thermal plumes ascend and descend in the cylinder sidewall boundary layer, forming an essentially one-dimensional pattern characterized by the number of hot and cold plume pairs. In our numerical study, we use the physical parameters corresponding to aqueous mixtures of glycerine with mass concentration in the range of 60%-90% glycerine and a Rayleigh number range that extends from the threshold for wall modes up to values where the bulk fluid region is also convecting. The study shows that for the range of Rayleigh numbers considered, the local variations in viscosity due to temperature variation in the flow are negligible. However, the mean viscosity, which varies faster than exponentially with variations in the percentage of glycerine, leads to a faster than exponential increase in the Froude number for a fixed Coriolis force, and hence an enhancement of the centrifugal buoyancy effects with significant dynamical consequences, which are detailed. © 2014 American Physical Society.Postprint (published version

Confined rotating convection with large Prandtl number: centrifugal effects on wall modes

Thermal convection in a rotating cylinder with a radius-to-height aspect ratio of G=4 for fluids with large Prandtl number is studied numerically. Centrifugal buoyancy effects are investigated in a regime where the Coriolis force is relatively large and the onset of thermal convection is in the so-called wall modes regime, where pairs of hot and cold thermal plumes ascend and descend in the cylinder sidewall boundary layer, forming an essentially one-dimensional pattern characterized by the number of hot and cold plume pairs. In our numerical study, we use the physical parameters corresponding to aqueous mixtures of glycerine with mass concentration in the range of 60%-90% glycerine and a Rayleigh number range that extends from the threshold for wall modes up to values where the bulk fluid region is also convecting. The study shows that for the range of Rayleigh numbers considered, the local variations in viscosity due to temperature variation in the flow are negligible. However, the mean viscosity, which varies faster than exponentially with variations in the percentage of glycerine, leads to a faster than exponential increase in the Froude number for a fixed Coriolis force, and hence an enhancement of the centrifugal buoyancy effects with significant dynamical consequences, which are detailed. © 2014 American Physical Society

Very high resolution tools for the monitoring and assessment of environmental hazards in coastal areas

Recently, new steps have been taken for the development of operational applications in coastal areas which require very high resolutions both in modeling and remote sensing products. In this context, this work describes a complete monitoring of an oil spill: we discuss the performance of high resolution hydrodynamic models in the area of Gran Canaria and their ability for describing the evolution of a real-time event of a diesel fuel spill, well-documented by port authorities and tracked with very high resolution remote sensing products. Complementary information supplied by different sources enhances the description of the event and supports their validation.The authors acknowledge support from IMPRESSIVE, a project funded by the European Union's Horizon 2020 research and innovation programme under grant agreement No 821922. The authors acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI). SW acknowledges the support of ONR Grant No. N00014-01-1-0769.Peer reviewe

Matemáticas del planeta Tierra : unidad didáctica

Con: Matemáticas del planeta Tierra : [cuaderno de actividades] / Fernando Alcaide, Miguel NietoResumen basado en el de la publicaciónRevisor didáctico: Luis RicoEsta unidad didáctica nace dentro de una iniciativa internacional de gran relevancia, la proclamación de 2013 como Año de las Matemáticas del Planeta Tierra (Mathematics Planet Earth, MPE 2013). Esta declaración ha tenido su origen en las sociedades matemáticas e institutos de investigación de Estados Unidos y Canadá, y posteriormente ha recibido el apoyo de la Unión Matemática Internacional (IMU) y la UNESCO. El objetivo del MPE 2013 es señalar la importancia de las matemáticas para conocer y gestionar mejor el funcionamiento de nuestro planeta –su propia estructura, la vida que alberga, los fenómenos en su corteza, en su atmósfera y en sus océanos, la influencia de la actividad humana, nuestro entorno astronómico– y también para estar mejor preparados ante catástrofes que nos alcanzan a veces de una manera terrible. Se ha dividido la obra en 16 capítulos, desarrollado cada uno de ellos por expertos en el tema y con materiales complementarios (libros, películas, series televisivas, portales de Internet) que pueden resultar de utilidad en las clases para amenizar e ilustrar los textos.ES

Challenge 6: Polar Oceans

19 pages, 1 figureThe Arctic and the Antarctic are the regions where temperature has raised most and faster than any other Earth’s place, producing a large number of impacts and feedback to the polar/climate system. Moreover, since polar oceans play a fundamental role in the Earth’s climate and global ecosystem, those changes produce climate consequences at mid latitudes . The study and monitoring of the poles from a global perspective and holistically is fundamental to better assess and understand the changes the polar regions are facing and its consequences on ocean circulation and climate, changes on the oceanic biogeochemistry composition and consequences on the oceanic living beings. Understanding the past to infer the future is another important leg to understand how the whole system is changing. The revision of the going on transformation and the continuous monitoring can be achieved with the combination of large amounts of observations (in situ and remote sensing) and numerical modelsPeer reviewe