1. Decadal Climate Prediction Project (DCPP) © Crown copyright 09/2015 | Met Office and the Met Office logo are registered trademarks Met Office FitzRoy Road, Exeter, Devon, EX1 3PB United Kingdom Co chairs: George Boer, Environment Canada, George.Boer@ec.gc.caGeorge.Boer@ec.gc.ca Doug Smith, Met Office, doug.smith@metoffice.gov.ukdoug.smith@metoffice.gov.uk http://wcrp-climate.org/dcpp-project/dcpp-introduction The DCPP consists of three components: Component A: Hindcasts. The design and organization of a coordinated decadal prediction (hindcast) component of CMIP6 in conjunction with the seasonal prediction and climate modelling communities Component B: Forecasts. The ongoing production of experimental quasi-operational decadal climate predictions in support of multi-model annual to decadal forecasting and the application of the forecasts Component C: Predictability, mechanisms and case studies. The organization and coordination of decadal climate predictability studies and of case studies of particular climate shifts and variations including the study of the mechanisms that determine these behaviours WGSIPWGCM What is the effect of volcanoes on multi-model forecast skill? What is the potential effect of a volcano on future forecasts? What are the mechanisms through which volcanoes influence climate? Component C: Volcanoes Link to VolMIP Component B: Forecasts Informal exchange of decadal predictions since 2011 http://www.metoffice.gov.uk/research/climate/seasonal-to-decadal/long-range/decadal-multimodel Aim to formalise following WMO seasonal forecasting framework Atlantic overturning circulation weakening Atlantic predicted to cool Likely climate impacts:  cold winters and wet summers in Europe less likely  fewer hurricanes than recent peaks  reduced Sahel rainfall  reduced risk of drought in SW USA More work needed to understand mechanisms → Component C Hermanson et al, 2014, GRL Component A: Hindcasts Assess likely forecast skill Remove bias from forecasts Component C: Hiatus+ : Accelerated and retarded rates of global temperature change and associated regional climate variations Investigate the origin, mechanisms and predictability of long timescale variations in global mean temperature and regional variables including periods of both enhanced warming and cooling with a focus on the current “hiatus” Link to GMMIP Kosaka and Xie, 2013, Nature Warming slowdown driven by tropical east Pacific SSTs Negative PDO driven by increase in Pacific trade winds drives Possible role of North Atlantic? England et al, 2014, Nature Climate Change Doblas-Reyes et al, 2013, Nature Comms High skill for temperature, including extremes, from warming trend Improvement from initialisation mainly in the North Atlantic Comes from improved prediction of ocean dynamics Some skill for associated climate impacts  Atlantic hurricane frequency  Rainfall over US, Sahel, Europe associated with rapid Atlantic warming in mid 1990s Model signal-to-noise ratio too small – need large ensembles Need improved models to reproduce climate impacts over land Pohlmann et al, 2013, Clim. Dyn. Hurricane shift 1995 Rainfall changes after 1995 Atlantic warming Smith et al, 2014, J. Clim.Eade et al, 2015, GRL Robson et al, 2013, J. Clim. Smith et al, 2010, Nat. Geosci. Smeed et al, 2014, Ocean Science McGregor et al, 2014, Nature Climate Change