Potential for seasonal prediction of the Atlantic sea surface temperatures using the RAPID array at 26°N

The Atlantic meridional overturning circulation (AMOC) plays a critical role in the climate system and is responsible for much of the meridional heat transported by the ocean. In this paper, the potential of using AMOC observations from the 26 ∘ N RAPID array to predict North Atlantic sea surface temperatures is investigated for the first time. Using spatial correlations and a composite method, the AMOC anomaly is used as a precursor of North Atlantic sea-surface temperature anomalies (SSTAs). The results show that the AMOC leads a dipolar SSTA with maximum correlations between 2 and 5 months. The physical mechanism explaining the link between AMOC and SSTA is described as a seesaw mechanism where a strong AMOC anomaly increases the amount of heat advected north of 26 ∘ N as well as the SSTA, and decreases the heat content and the SSTA south of this section. In order to further understand the origins of this SSTA dipole, the respective contributions of the heat advected by the AMOC versus the Ekman transport and air–sea fluxes have been assessed. We found that at a 5-month lag, the Ekman component mainly contributes to the southern part of the dipole and cumulative air–sea fluxes only explain a small fraction of the SSTA variability. Given that the southern part of the SSTA dipole encompasses the main development region for Atlantic hurricanes, our results therefore suggest the potential for AMOC observations from 26 ∘ N to be used to complement existing seasonal hurricane forecasts in the Atlantic

Western boundary circulation and coastal sea-level variability in Northern Hemisphere oceans

The northwest basins of the Atlantic and Pacific oceans are regions of intense western boundary currents (WBCs): the Gulf Stream and the Kuroshio. The variability of these poleward currents and their extensions in the open ocean is of major importance to the climate system. It is largely dominated by in-phase meridional shifts downstream of the points at which they separate from the coast. Tide gauges on the adjacent coastlines have measured the inshore sea level for many decades and provide a unique window on the past of the oceanic circulation. The relationship between coastal sea level and the variability of the western boundary currents has been previously studied in each basin separately, but comparison between the two basins is missing. Here we show for each basin that the inshore sea level upstream of the separation points is in sustained agreement with the meridional shifts of the western boundary current extension over the period studied, i.e. the past 7 (5) decades in the Atlantic (Pacific). Decomposition of the coastal sea level into principal components allows us to discriminate this variability in the upstream sea level from other sources of variability such as the influence of large meanders in the Pacific. Our result extends previous findings limited to the altimetry era and suggests that prediction of inshore sea-level changes could be improved by the inclusion of meridional shifts of the western boundary current extensions as predictors. Long-duration tide gauges, such as Key West, Fernandina Beach or Hosojima, could be used as proxies for the past meridional shifts of the western boundary current extensions

The Atlantic meridional overturning circulation in high resolution models

The Atlantic meridional overturning circulation (AMOC) represents the zonally integrated stream function of meridional volume transport in the Atlantic Basin. The AMOC plays an important role in transporting heat meridionally in the climate system. Observations suggest a heat transport by the AMOC of 1.3 PW at 26°N ‐ a latitude which is close to where the Atlantic northward heat transport is thought to reach its maximum. This shapes the climate of the North Atlantic region as we know it today. In recent years there has been significant progress both in our ability to observe the AMOC in nature and to simulate it in numerical models. Most previous modeling investigations of the AMOC and its impact on climate have relied on models with horizontal resolution that does not resolve ocean mesoscale eddies and the dynamics of the Gulf Stream/North Atlantic Current system. As a result of recent increases in computing power, models are now being run that are able to represent mesoscale ocean dynamics and the circulation features that rely on them. The aim of this review is to describe new insights into the AMOC provided by high‐resolution models. Furthermore, we will describe how high‐resolution model simulations can help resolve outstanding challenges in our understanding of the AMOC

Espaces de la chanson contemporaine

International audienc

Spreadsheets for GSNW, KEI and tide gauge derived sea-level modes

A set of CSV files containing different timeseries presented in Ocean Science paper &#39;Western boundary circulation and coastal sea-level variability in northern hemisphere oceans&#39;, from Samuel Ti&eacute;folo Diabat&eacute; and Coauthors (submitted). - Atlantic_PCs.csv: contains the two leading principal components of the tide gauge obtained sea-level anomalies for the Atlantic set of tide gauges. - Pacific_PCs.csv: same as previous, but for the Pacific set of tide gauges. - GSNW.csv: contains our Gulf Stream North Wall index, as defined in the paper. - KEI.csv: contains our Kuroshio Extension Index, as defined in the paper.</span

Chanson et intertextualité

Contrafacta, fricassées, timbres ou reprises, du Moyen Âge au xxe siècle, la chanson a toujours goûté le plaisir de la création seconde, pour mieux enchanter l’auditeur. Mais sont-ce seulement quelques récréations que ces compositions entées ? En montrant comment elles sont éclairées par et éclairent à leur tour la poétique de l’intertextualité, l’objet de cet ouvrage est de montrer la portée re-créatrice de ces oeuvres entées. Ce parcours à travers les âges et les domaines linguistiques expose à la fois la vitalité des recherches cantologiques actuelles et celles des travaux sur la théorie de l’intertexte. Comme espace du topos et de la parole mémorielle, la chanson est, entre autres manifestations de la poésie orale, particulièrement perméable aux procédés d’emprunt, réemplois et réfections diverses qui caractérisent la poétique de l’intertextualité. Elle l’est même doublement : comme oeuvre, elle est formellement fondée sur les figures de récurrence ; comme espace générique, elle est le lieu privilégié de la tradition, comprise comme mode de transmission d’un message culturel dans un temps donné. Au-delà du seul texte, le tissage sémiologique singulier du genre chanson fonctionne comme réceptacle particulier du discours autre et du discours de l’Autre : non seulement la chanson cite, réécrit, voire plagie textes et musiques, mais, chaque performance étant une autre oeuvre, elle investit le champ de la recréation par le jeu des réinterprétations. On a voulu questionner ici l’articulation entre ces présences « autres » et la corporéité de la voix transmise qui reste la visée du discours chansonnier