Regional versus remote atmosphere‐ocean drivers of the rapid projected intensification of the East Australian Current
Like many western boundary currents, the East Australian Current extension is projected to get stronger and warmer in the future. The CMIP5 multi‐model mean (MMM) projection suggests up to 5°C of warming under an RCP85 scenario by 2100. Previous studies employed Sverdrup balance to associate a trend in basin wide zonally integrated wind stress curl (resulting from the multi‐decadal poleward intensification in the westerly winds over the Southern Ocean) with enhanced transport in the EAC extension. Possible regional drivers are yet to be considered. Here, we introduce the NEMO‐OASIS‐WRF coupled regional climate model as a framework to improve our understanding of CMIP5 projections. We analyse a hierarchy of simulations in which the regional atmosphere and ocean circulations are allowed to freely evolve subject to boundary conditions that represent present day and CMIP5 RCP8.5 climate change anomalies. Evaluation of the historical simulation shows an EAC extension that is stronger than similar ocean‐only models and observations. This bias is not explained by a linear response to differences in wind stress. The climate change simulations show that regional atmospheric CMIP5 MMM anomalies drive 73% of the projected 12 Sv increase in EAC extension transport whereas the remote ocean boundary conditions and regional radiative forcing (greenhouse gases within the domain) play a smaller role. The importance of regional changes in wind stress curl in driving the enhanced EAC extension is consistent with linear theory where the NEMO‐OASIS‐WRF response is closer to linear transport estimates compared to the CMIP5 MMM.
Press Association Stoke boss Tony Pulis accepts his side are up against “overwhelming odds” as they host runaway Barclays Premier League leaders Manchester United this weekend. Pulis added: “We have to pick a team we think will work as hard as they possibly can to nullify their strengths, and also give us an opportunity to compete at the other end of the pitch as well.” Alarm bells have started ringing at the Britannia Stadium after a dismal run of just one win in 13 league games. They have kept only one clean sheet in the last 14 and scored just two in the last six. The Potters were five points off the Champions League places at Christmas but after last weekend’s results they found themselves just three above the relegation zone. It is an unfamiliar position for the club having held their own since promotion to the top flight in 2008, and underlined their progress by reaching an FA Cup final and playing in Europe. But in a 21-year managerial career that has taken him through the divisions, Pulis feels he is equipped to deal with the challenge. “I think publicity-wise it is the hardest time I’ve had – but I have had tougher times with teams that haven’t been as good as this one, and you’ve had to eke out results,” said Pulis, who has managed six clubs. “But everything that goes with the Premier League is magnified and multiplied enormously. We have to concentrate on ourselves and not take too much notice of what is going on around us. “You have got to stay focused and stay strong. I don’t get too up or too down in lots of respects. I do lose my temper now and again but in respect of being level and strong, you have to stand up and I don’t mind doing that.” United, 12 points clear at the top of table with seven games to play, are striding towards a record-extending 20th title while the Potters struggle at the opposite end. Sir Alex Ferguson’s men did suffer defeat to rivals Manchester City in their derby last Monday but Pulis sees that as a mere blip. He said: “I think you have got to recognise the strength they have got. You have got to recognise you are competing against overwhelming odds in a lot of respects. That is why they are champions-elect – they have got the best team and the best players.”