Downscaling ECMWF seasonal precipitation forecasts in Europe using the RCA model

The operational performance and usefulness of regional climate models at seasonal time scales are assessed by downscaling an ensemble of global seasonal forecasts. The Rossby Centre RCA regional model was applied to downscale a five-member ensemble from the ECMWF System3 global model in the European Atlantic domain for the period 1981–2001. One month lead time global and regional precipitation predictions were compared over Europe—and particularly over Spain—focusing the study in SON (autumn) dry events. A robust tercile-based probabilistic validation approach was applied to compare the forecasts from global and regional models, obtaining significant skill in both cases, but over a wider area for the later. Finally, we also analyse the performance of a mixed ensemble combining both forecasts

Climate change projections for olive yields in the Mediterranean Basin

The olive tree is one of the most important crops in the Mediterranean basin. Given the strong climatic influence on olive trees, it becomes imperative to assess climate change impacts on this crop. Herein, these impacts were innovatively assessed, based on an ensemble of state-of-the-art climate models, future scenarios and dynamic crop models. The recent-past (1989-2005) and future (2041-2070, RCP4.5 and RCP8.5) olive growing season length (GSL), yield, growing season temperature (GST) and precipitation (GSP), potential (ETP) and actual (ETA) evapotranspiration, water demand (WD) and water productivity (WP) were assessed over Southern Europe. Crop models were fed with an ensemble of EURO-CORDEX regional climate model data, along with soil and terrain data. For the recent-past, important differences between western and eastern olive growing areas are found. GSL presents a strong latitudinal gradient, with higher/lower values at lower/higher latitudes. Yields are lower in inner south Iberia and higher in Italy and Greece, which is corroborated by historical data. Southern Iberia shows higher GST and lower GSP, which contributes to a higher ETP, lower ETA and, consequently, stronger WD. Regarding WP, the recent-past values show similar ranges across Europe. Future projections point to a general increase in GSL along with an increase in GST up to 3 degrees C. GSP is projected to decrease in Western Europe, leading to enhanced WD and consequently a yield decrease (down to -45%). Over eastern European, GSP is projected to slightly increase, leading to lower WD and to a small yield increase (up to +15%). WP will remain mostly unchanged. We conclude that climate change may negatively impact the viability of olive orchards in southern Iberia and some parts of Italy. Thus, adequate and timely planning of suitable adaptation measures are needed to ensure the sustainability of the olive sector

The R-based climate4R open framework for reproducible climate data access and post-processing

Climate-driven sectoral applications commonly require different types of climate data (e.g. observations, re-analysis, climate change projections) from different providers. Data access, harmonization and post-processing(e.g. bias correction) are time-consuming error-prone tasks requiring different specialized software tools at eachstage of the data workflow, thus hindering reproducibility. Here we introduce climate4R, an R-based climateservices oriented framework tailored to the needs of the vulnerability and impact assessment community thatintegrates in the same computing environment harmonized data access, post-processing, visualization and aprovenance metadata model for traceability and reproducibility of results. climate4R allows accessing localand remote (OPeNDAP) data sources, such as the Santander User Data Gateway (UDG), a THREDDS-basedservice including a wide catalogue of popular datasets (e.g. ERA-Interim, CORDEX, etc.). This provides a uniquecomprehensive open framework for end-to-end sectoral reproducible applications. All the packages, data anddocumentation for reproducing the experiments in this paper are available from http://www.meteo.unican.es/climate4R.This work has been funded by the Spanish R+D Program of theMinistry of Economy and Competitiveness, through grants MULTI-SDM(CGL2015-66583-R) and INSIGNIA (CGL2016-79210-R), co-funded byERDF/FEDER. We would like to thank the two anonymous reviewersfor their valuable suggestions and comments