Laboratoire de Météorologie Dynamique

Three-dimensional circulation controls on pollutant retention and mucilage accumulation in the sea of Marmara: A Lagrangian perspective

The Sea of Marmara is undergoing a severe marine pollution crisis driven by chronic nutrient enrichment and recurrent mucilage outbreaks. The physical mechanisms controlling transport, accumulation and persistence of pollutants and organic matter remain insufficiently resolved. H...

Marine Heat Waves and Cold Spells – Multiple Analysis/Definitions (MHW-MAD): A Multi-Definition Global Marine Heatwave Database from Satellite Sea Surface Temperature Data

Marine heatwaves (MHWs) are prolonged anomalies of warm sea surface temperature (SST) that can disrupt marine ecosystems, physical climate processes, and human coastal activities. MHW definitions vary due to different stakeholders requirements, such as ecological scientists and c...

Projecting Impacts of Marine Heatwaves and Their Effects on Long‐Term Changes in Marine Ecosystems Over the 21st Century

ABSTRACT Marine heatwaves (MHWs) are increasing in frequency, duration and intensity under climate change. Although current MHWs trigger broad ecological impacts, such as coral bleaching, mass mortality of seagrass meadows, and declines in important fish stocks, the cascading eff...

The Cold-Air Outbreaks in the Marine Boundary Layer Experiment model-observation intercomparison project (COMBLE-MIP) – Part 1: Model specification, observational constraints, and preliminary findings

Models struggle to represent the coupled microphysical, turbulent and radiative processes within widespread, long-lived marine cold-air outbreak (CAO) cloud fields, contributing to forecast and climate biases. Here we combine ground-based and satellite measurements to initialize...

Rare events algorithm study of extreme double jet summers and their connection with heatwaves over the Northern Hemisphere

Abstract Several large scale circulation patterns have been identified in relation to extreme Northern Hemisphere summer heatwaves. Three main ones are a double jet over Eurasia, a positive phase of the summer northern annular mode, and a quasi-wave-3 geopotential height anomaly....

Evidence for the impact of fire activity on daily variations of IASI mid-tropospheric CO 2 anomalies at 8–11 km over South America: a pyroconvective fingerprint

Biomass burning is a major, highly variable source of atmospheric CO 2 , but its impact on the free troposphere remains difficult to quantify because of uncertainties in injection heights and transport. In the tropics, intense fires can trigger pyroconvective plumes that loft com...

Extratropical teleconnections in a multi-model ensemble nudged towards the observed QBO

The Quasi-Biennial Oscillation (QBO), the dominant mode of interannual variability of monthly-mean zonal winds and temperatures in the equatorial stratosphere, has a significant influence on the circulation in other regions of the stratosphere and troposphere in boreal winter. To...

The added value of Med-CORDEX coupled high-resolution regional climate models in representing sea surface temperature and marine heatwaves in the Mediterranean Sea

Marine heatwaves (MHWs) pose significant threats to Mediterranean marine ecosystems and coastal economies, with frequency and severity projected to increase under future climate change. While Med-CORDEX fully-coupled Regional Climate System Models (RCSMs) offer enhanced resolutio...

Beyond wind-induced upwelling: diverse drivers of future productivity in eastern boundary upwelling systems

Abstract. Eastern Boundary Upwelling Systems (EBUS) contribute disproportionately to global marine productivity and fisheries, yet their response to climate change remains poorly understood. Given the essential ecosystem services they support, improving projections of future EBUS...

A barycenter-based approach for the multi-model ensembling of subseasonal forecasts

Abstract. Ensemble forecasts and their combination are examined from the perspective of probability spaces. By treating ensemble forecasts as discrete probability distributions, multi-model ensemble (MME) forecasts are reformulated as barycenters of these distributions. We consid...

Contrasting seasonal roles of external forcing and internal variability in East Asian temperature

How to reliably separate external forcing (EXF) and internal variability (IV) components of regional temperature variation is of critical importance in East Asia. We implement here an EOF-based semi-empirical framework to avoid spurious teleconnections often present with conventi...