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The importance of stratospheric initial conditions for winter North Atlantic Oscillation predictability and implications for the signal-to-noise paradox

This study investigates the influence of atmospheric initial conditions on winter seasonal forecasts of the North Atlantic Oscillation (NAO). Hindcast (or reforecast) experiments – which differ only in their initial conditions – are performed over …

Recent multivariate changes in the North Atlantic climate system, with a focus on 2005–2016

Major changes are occurring across the North Atlantic climate system, including in the atmosphere, ocean and cryosphere, and many observed changes are unprecedented in instrumental records. As the changes in the North Atlantic directly affect the …

The Signature of Oceanic Processes in Decadal Extratropical SST Anomalies

The relationship between decadal sea surface temperature (SST) and turbulent heat fluxes is assessed and used to identify where oceanic processes play an important role in extratropical decadal SST variability. In observational data sets and coupled …

The Impact of Tropical Precipitation on Summertime Euro-Atlantic Circulation via a Circumglobal Wave Train

The influence of tropical precipitation variability on summertime seasonal circulation anomalies in the Euro-Atlantic sector is investigated. The dominant mode of the maximum covariance analysis (MCA) between the Euro-Atlantic circulation and …

Flow dependent ensemble spread in seasonal forecasts of the boreal winter extratropics

Flow-dependent spread (FDS) is a desirable characteristic of probabilistic forecasts; ensemble spread should represent the expected forecast error. However this is difficult to estimate for seasonal hindcasts as they tend to have a relatively small …

Skilful Seasonal Predictions of Summer European Rainfall

Year-to-year variability in Northern European summer rainfall has profound societal and economic impacts; however, current seasonal forecast systems show no significant forecast skill. Here we show that skillful predictions are possible (r ~0.5, p < …

Impact of Gulf Stream SST biases on the global atmospheric circulation

The UK Met Office Unified Model in the Global Coupled 2 (GC2) configuration has a warm bias of up to almost $$7$backslash$,$backslash$hbox K$$7Kin the Gulf Stream SSTs in the winter season, which is associated with surface heat flux biases and …

Interdecadal variability of the ENSO teleconnection to the wintertime North Pacific

The El Niño/Southern Oscillation (ENSO) strongly influences the large-scale atmospheric circulation over the extratropical North Pacific during boreal winter, which has an important impact on North American winter climate. This study analyses the …

Challenges and opportunities for improved understanding of regional climate dynamics

Dynamical processes in the atmosphere and ocean are central to determining the large-scale drivers of regional climate change, yet their predictive understanding is poor. Here, we identify three frontline challenges in climate dynamics where …

The Dynamical Influence of the Atlantic Multidecadal Oscillation on Continental Climate

The Atlantic multidecadal oscillation (AMO) in sea surface temperature (SST) has been shown to influence the climate of the surrounding continents. However, it is unclear to what extent the observed impact of the AMO is related to the thermodynamical …