Role of oceandynamics and Ocean-Atmosphere interactions in Driving cliMAte variations andfutureProjections of impact-relevant extreme events

Informations

Funding country

Norway

Acronym

-

URL

-

Start date

1/1/2020

End date

12/31/2024

Budget

778,590 EUR

Fundings

Abstract

ROADMAP aims to expand current understanding of how the Northern Hemisphere oceans’ surface state (i.e., temperature, sea ice cover) and dynamics (i.e., water movement) influence the extratropical atmospheric circulation and associated weather and climate extreme events. The project does this across a wide range of space- and timescales, short-synoptic to decadal-planetary, under both present day and future climate conditions. Funded by the EU JPI CLIMATE and JPI OCEANS joint call on next generation climate science in Europe for Oceans, ROADMAP is led by the Max-Plank Institute for Meteorology (Germany) and brings together leading climate research institutions from seven European countries, including universities as well as weather and climate services providers. Norway participates through the Geophysical Institute (University of Bergen) and the Nansen Environmental and Remote Sensing Center. Two-years into the project, these are the findings that Norway has contributed to: • In addition to global warming, the Pacific and Atlantic multi-decadal variability jointly contribute to fluctuations in Arctic climate over the historical period (1900 to present), through ocean and atmospheric teleconnections (Svendsen et al. 2021) • Using long-term forced model simulation, real world observations and model reanalysis data, we show that a large part of multidecadal variability in the North Atlantic climate can be physically explained by coupled oscillation that links stratospheric and tropospheric jets with ocean circulation (Omrani et al., 2022). • Using coordinated multi-model large ensemble simulations, we showed that the internally driven interdecadal Paci?c oscillation brings a cooling trend over the western part of the Eurasian Cooling region during 1998-2013 (Suo et al., 2022). • Climate models (historical and decadal predictions) struggle to represent the correct thermohaline anomalies along the Atlantic water pathway from the North Atlantic Ocean towards the Arctic Ocean (Langehaug et al., 2022). • Uncertainties in mid-latitude climate change were related to tropical Pacific forcing and extra-tropical air-sea interactions in the Atlantic (Cheung et al. 2022). • In joint work with other ROADMAP partners, the importance of resolving the Gulf Stream sea surface temperature front for North Atlantic climate was demonstrated (Athanasiadis et al. 2022). • We also showed the potential of decadal predictions of key fish stock in the North Atlantic derived from multi-decadal climate variability (Payne et al. 2022). • Based on a unique set of multi-model large-ensemble atmospheric simulations, we have isolated the respective contributions from the combined external radiative forcing, interdecadal Pacific variability, Atlantic multidecadal variability, and Arctic sea-ice changes to the Arctic tropospheric warming during 1979-2013 (Suo et al., accepted). • The mechanisms by which the North Atlantic Oscillation drives the shift of the Gulf Stream more-or-less every ten years have been identified (Famooss Paolini et al., results not yet published). • Using semi-idealized atmosphere model experiments, we showed that Atlantic and Pacific mid-latitude sea surface temperature fronts jointly maintain the observed North Euro-Atlantic (Cheung et. al. in revision) and Ural blocking frequency (Cheung et. al. in revision). • Using atmosphere-only model experiments, we show that the sea surface temperature in the tropics controls the stratospheric response to climate change through non-conservative processes such as the diabatic heating and diffusive mixing (Omrani et. al., submitted). • To detect and understand the impact of the subpolar North Atlantic Ocean on the surrounding regions, we have performed standard pacemaker experiments by constraining the simulated temperature and salinity in the subpolar North Atlantic Ocean toward observed values. We find that salinity variability in the Norwegian Sea and towards the Arctic Ocean is improved in these experiments (Langehaug et al., work in progress). We have also undertaken pacemaker experiments to understand tropical basin interactions. Project website: http://roadmap.rd.ciencias.ulisboa.pt/index.html#about