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[Resumen]: El desarrollo de sistemas computacionales de apoyo al diagnóstico tiene especial relevancia en la práctica clínica moderna, y especialmente en el ámbito oftalmológico. Su mayor impacto social se encuentra probablemente en la prevención de enfermedades graves, que afectan a grandes sectores de la población envejecida de los países desarrollados, por su alto riesgo de mortalidad y discapacidad grave. Ejemplos de estas enfermedades son la hipertensión y diabetes, así como las afecciones oculares con mayor riesgo de ceguera, como el glaucoma, la retinopatía diabética o la degeneración macular asociada a la edad. Para ello, se requieren sistemas de diagnóstico que cubran un amplio espectro de enfermedades (multi-patología), basados en modalidades de imagen asequibles como la retinografía de ambos ojos del mismo paciente. ODIR-2019 es un challenge que proporciona el dataset ODIR-5K, compuesto por pares de imágenes de retina, correspondientes a los dos ojos de una misma persona, recopiladas por diferentes hospitales usando diferentes retinógrafos a color. Cada uno de los pacientes está asociado a múltiples etiquetas simultáneas, indicando presencia de una o varias enfermedades en alguno de los ojos: normal/sano (N), diabetes (D), glaucoma (G), cataratas (C), AMD (A), hipertensión (H), miopía (M) y otras enfermedades (O). El etiquetado se basa en ambas retino- grafías. Trabajar a nivel de par puede ser beneficioso para el aprendizaje de los modelos debido a la correlación entre los dos ojos. En cuanto a la clasificación multi-etiqueta, esta presenta más retos y está menos documentada que la binaria y la multiclase, pero es muy útil en este caso ya que un solo modelo puede informar sobre el padecimiento de varias enfermedades con una sola evaluación. En este trabajo se experimenta con diferentes técnicas de deep learning buscando cons- truir el modelo que dé los mejores resultados sobre ODIR-5K. Para ello, se partirá de un modelo de clasificación base, y se adapta

[Abstract]: Retinal image registration is of utmost importance due to its wide applications in medical practice. In this context, we propose ConKeD, a novel deep learning approach to learn descriptors for retinal image registration. In contrast to current registration methods, our approach employs a novel multi-positive multi-negative contrastive learning strategy that enables the utilization of additional information from the available training samples. This makes it possible to learn high-quality descriptors from limited training data. To train and evaluate ConKeD, we combine these descriptors with domain-specific keypoints, particularly blood vessel bifurcations and crossovers, that are detected using a deep neural network. Our experimental results demonstrate the benefits of the novel multi-positive multi-negative strategy, as it outperforms the widely used triplet loss technique (single-positive and single-negative) as well as the single-positive multi-negative alternative. Additionally, the combination of ConKeD with the domain-specific keypoints produces comparable results to the state-of-the-art methods for retinal image registration, while offering important advantages such as avoiding pre-processing, utilizing fewer training samples, and requiring fewer detected keypoints, among others. Therefore, ConKeD shows a promising potential towards facilitating the development and application of deep learning-based methods for retinal image registration.

[Absctract]: Water quality can be negatively affected by the presence of some toxic phytoplankton species, whose toxins are difficult to remove by conventional purification systems. This creates the need for periodic analyses, which are nowadays manually performed by experts. These labor-intensive processes are affected by subjectivity and expertise, causing unreliability. Some automatic systems have been proposed to address these limitations. However, most of them are based on classical image processing pipelines with not easily scalable designs. In this context, deep learning techniques are more adequate for the detection and recognition of phytoplankton specimens in multi-specimen microscopy images, as they integrate both tasks in a single end-to-end trainable module that is able to automatize the adaption to such a complex domain. In this work, we explore the use of two different object detectors: Faster R-CNN and RetinaNet, from the one-stage and two-stage paradigms respectively. We use a dataset composed of multi-specimen microscopy images captured using a systematic protocol. This allows the use of widely available optical microscopes, also avoiding manual adjustments on a per-specimen basis, which would require expert knowledge. We have made our dataset publicly available to improve the reproducibility and to foment the development of new alternatives in the field. The selected Faster R-CNN methodology reaches maximum recall levels of 95.35%, 84.69%, and 79.81%, and precisions of 94.68%, 89.30% and 82.61%, for W. naegeliana, A. spiroides, and D. sociale, respectively. The system is able to adapt to the dataset problems and improves the results overall with respect to the reference state-of-the-art work. In addition, the proposed system improves the automation and abstraction from the domain and simplifies the workflow and adjustment.

[Abstract]: Multi-task learning is a promising paradigm to leverage task interrelations during the training of deep neural networks. A key challenge in the training of multi-task networks is to adequately balance the complementary supervisory signals of multiple tasks. In that regard, although several task-balancing approaches have been proposed, they are usually limited by the use of per-task weighting schemes and do not completely address the uneven contribution of the different tasks to the network training. In contrast to classical approaches, we propose a novel Multi-Adaptive Optimization (MAO) strategy that dynamically adjusts the contribution of each task to the training of each individual parameter in the network. This automatically produces a balanced learning across tasks and across parameters, throughout the whole training and for any number of tasks. To validate our proposal, we perform comparative experiments on real-world datasets for computer vision, considering different experimental settings. These experiments allow us to analyze the performance obtained in several multi-task scenarios along with the learning balance across tasks, network layers and training steps. The results demonstrate that MAO outperforms previous task-balancing alternatives. Additionally, the performed analyses provide insights that allow us to comprehend the advantages of this novel approach for multi-task learning.

[Abstract]: Retinal vascular tortuosity is an excessive bending and twisting of the blood vessels in the retina that is associated with numerous health conditions. We propose a novel methodology for the automated assessment of the retinal vascular tortuosity from color fundus images. Our methodology takes into consideration several anatomical factors to weigh the importance of each individual blood vessel. First, we use deep neural networks to produce a robust extraction of the different anatomical structures. Then, the weighting coefficients that are required for the integration of the different anatomical factors are adjusted using evolutionary computation. Finally, the proposed methodology also provides visual representations that explain the contribution of each individual blood vessel to the predicted tortuosity, hence allowing us to understand the decisions of the model. We validate our proposal in a dataset of color fundus images providing a consensus ground truth as well as the annotations of five clinical experts. Our proposal outperforms previous automated methods and offers a performance that is comparable to that of the clinical experts. Therefore, our methodology demonstrates to be a viable alternative for the assessment of the retinal vascular tortuosity. This could facilitate the use of this biomarker in clinical practice and medical research.

[Absctract]: Background: Retinal imaging is widely used to diagnose many diseases, both systemic and eye-specific. In these cases, image registration, which is the process of aligning images taken from different viewpoints or moments in time, is fundamental to compare different images and to assess changes in their appearance, commonly caused by disease progression. Currently, the field of color fundus registration is dominated by classical methods, as deep learning alternatives have not shown sufficient improvement over classic methods to justify the added computational cost. However, deep learning registration methods are still considered beneficial as they can be easily adapted to different modalities and devices following a data-driven learning approach. Methods: In this work, we propose a novel methodology to register color fundus images using deep learning for the joint detection and description of keypoints. In particular, we use an unsupervised neural network trained to obtain repeatable keypoints and reliable descriptors. These keypoints and descriptors allow to produce an accurate registration using RANdom SAmple Consensus (RANSAC). We train the method using the Messidor dataset and test it with the Fundus Image Registration Dataset (FIRE) dataset, both of which are publicly accessible. Results: Our work demonstrates a color fundus registration method that is robust to changes in imaging devices and capture conditions. Moreover, we conduct multiple experiments exploring several of the method’s parameters to assess their impact on the registration performance. The method obtained an overall Registration Score of 0.695 for the whole FIRE dataset (0.925 for category S, 0.352 for P, and 0.726 for A). Conclusions: Our proposal improves the results of previous deep learning methods in every category and surpasses the performance of classical approaches in category A which has disease progression and thus represents the most relevant scenario for clinical practic

Copyright 2006 by the American Geophysical Union. We thank two anonymous reviewers and B. Stevens for comments. This work was partially funded by the EUproject SO&P, projects REN2002-04584-C04-CLI and CGL2005-06097 of the spanish MEC and in Canada by NSERC, CFCAS and AIF., A heat-conduction forward model driven by ground surface temperature from three 1000-year climate simulations with the state-of-the-art ECHO-g model has been used to simulate underground temperature perturbation profiles. An inversion approach has been applied to reconstruct ground surface temperature histories from the simulated profiles and to compare them with the climate model temperatures. Results support the skill of borehole inversion methods to retrieve long-term temperature trends, and the robustness of using the present-day borehole network for reconstructing SAT variations., Ministerio de Educación y Ciencia (MEC), España, Natural Sciences and Engineering Research Council of Canada (NSERC), Canadian Foundation for Climate and Atmospheric Sciences (CFCAS), Canadá, Atlantic Innovation Fund (AIF), Canadá, Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

© 2010 American Meteorological Society. The National Center for Atmospheric Research is sponsored by the National Science Foundation.This project was accomplished within the Collaboration Agreement 09/153 between UCM and CIEMAT, and it was partially funded by Project CGL2005-06966-C07/CLI. We thank the Navarra Government for providing us with the wind dataset used in this study and ECMWF for free access to its datasets. An initial version of the wavelet software was provided by C. Torrence and G. Compo (available online at http:// atoc.colorado.edu/research/). We also thank the three reviewers for their helpful comments., This study analyzes the daily-mean surface wind variability over an area characterized by complex topography through comparing observations and a 2-km-spatial-resolution simulation performed with the Weather Research and Forecasting (WRF) model for the period 1992-2005. The evaluation focuses on the performance of the simulation to reproduce the wind variability within subregions identified from observations over the 1999-2002 period in a previous study. By comparing with wind observations, the model results show the ability of the WRF dynamical downscaling over a region of complex terrain. The higher spatio-temporal resolution of the WRF simulation is used to evaluate the extent to which the length of the observational period and the limited spatial coverage of observations condition one's understanding of the wind variability over the area. The subregions identified with the simulation during the 1992-2005 period are similar to those identified with observations (1999-2002). In addition, the reduced number of stations reasonably represents the spatial wind variability over the area. However, the analysis of the full spatial dimension simulated by the model suggests that observational coverage could be improved in some subregions. The approach adopted here can have a direct application to the design of observational networks., National Science Foundation (NSF), Universidad Complutense de Madrid (UCM), Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

© 2012 American Meteorological Society. This investigation was partially supported by Projects CGL-2008-05093/CLI and CGL-2011-29677-C02 and was accomplished within the Collaboration Agreement 09/490 between CIEMAT and NCAR as well as the Collaboration Agreement 09/153 between CIEMAT and UCM. NCAR is sponsored by the National Science Foundation. We thank the Navarra government for providing us with the observations used in this study. Discussion with Fei Chen and Peggy Lemone were helpful during this work. The authors would also like to thank Maria Tombrou for her comments regarding the similarity functions in unstable conditions. We would also like to thank the reviewers for their constructive comments., This study summarizes the revision performed on the surface layer formulation of the Weather Research and Forecasting (WRF) model. A first set of modifications are introduced to provide more suitable similarity functions to simulate the surface layer evolution under strong stable/unstable conditions. A second set of changes are incorporated to reduce or suppress the limits that are imposed on certain variables in order to avoid undesired effects (e. g., a lower limit in u_*). The changes introduced lead to a more consistent surface layer formulation that covers the full range of atmospheric stabilities. The turbulent fluxes are more (less) efficient during the day (night) in the revised scheme and produce a sharper afternoon transition that shows the largest impacts in the planetary boundary layer meteorological variables. The most important impacts in the near-surface diagnostic variables are analyzed and compared with observations from a mesoscale network., National Science Foundation (NSF), Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Universidad Complutense de Madrid (UCM), National Center for Atmospheric Research (NCAR), Depto. de Física Teórica, Fac. de Ciencias Físicas, TRUE, pub

Copyright 2008 by the American Geophysical Union. This research was funded by the Natural Sciences and Engineering Research Council of Canada (NSERC), the Atlantic Innovation Fund (ACOA), and project CGL2005-06097 of the Spanish MEC. M.B.S. was partially funded by a graduate fellowship from the Atlantic Computing Excellence Network (ACEnet). Part of this work was carried out while J.F.G.R. was a James Chair Professor at STFX. J.F.G.R. was additionally funded by a Ramón y Cajal grant. Special thanks to Lisa Kellman, Asfaw Bekele, Dave Risk, and Nick Nickerson for insightful conversations and to Louise Bodri and Robert Harris for their thoughtful reviews of an earlier version of the manuscript., General circulation models (GCMs) are currently able to provide physically consistent simulations of millennial climate variability in which estimations of external forcing factors are incorporated as boundary conditions. Climate reconstruction attempts to recover as faithfully as possible past climate variability using a variety of independent and climate-sensitive sources of information. By deriving strategies of comparison between GCM simulations and proxy data, or directly recorded data such as subsurface thermal profiles, the agreement between model and observations can be assessed. Thermal profiles obtained from the boreholes of North America were grouped into eight geographically discrete ensembles and averaged to form robust, representative profiles. The gridded output from the three distinct integrations of the GCM ECHO-g were similarly averaged by region. These simulated, millennial, paleoclimatic histories were then forward modeled to arrive at the subsurface thermal profiles that would result from the temperature trends at the surface. These forward modeled profiles were then compared with the borehole average thermal anomaly profile in each region. In most of the regions studied, the externally forced runs from ECHO-g are in better agreement with underground temperature anomalies than with the control run, suggesting that boreholes are sensitive to external forcing. Not only do ECHO-g simulations demonstrate better agreement with borehole data when considering variable external forcing factors, but ECHO-g also appears to broadly describe qualitative aspects of long-term climatic trends at a regional scale., Natural Sciences and Engineering Research Council of Canada (NSERC), Atlantic Innovation Fund (ACOA), Ministerio de Educación y Ciencia (MEC), España, Atlantic Computing Excellence Network (ACEnet), Programa Ramón y Cajal (MEC), Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

Copyright 2008 by the American Geophysical Union. This research was funded by grants from NSERC Discovery, AIF (ACOA), CFCAS, and ACEnet (HB); Ramón y Cajal (JFGR); NSERC PGS-D (MBS); and NSERC USRA (AHM)., Shallow bottom boundary conditions (BBCs) in the soil components of general circulation models (GCMs) impose artificial limits on subsurface heat storage. To assess this problem we estimate the subsurface heat content from two future climate simulations and compare to that obtained from an offline soil model (FDLSM) driven by GCM skin temperatures. FDLSM is then used as an offline substitute for the subsurface of the GCM ECHO-G. With a 600-m BBC and driven by ECHO-G future temperatures, the FDLSM subsurface absorbs 6.2 (7.5) times more heat than the ECHO-G soil model (10 m deep) under the Intergovernmental Panel on Climate Change (IPCC) A2 (B2) emission scenario. This suggests that shallow BBCs in GCM simulations may underestimate the heat stored in the subsurface, particularly for northern high latitudes. This effect could be relevant in assessing the energy balance and climate change in the next century., Natural Sciences and Engineering Research Council of Canada (NSERC), Atlantic Innovation Fund (AIF), Canadá, Canadian Foundation for Climate and Atmospheric Sciences (CFCAS), Atlantic Computational Excellence Network (ACEnet), Canadá, Programa Ramón y Cajal (MEC), NSERC PGS-D, Undergraduate Student Research Awards (USRA), NSERC, Atlantic Canada Opportunities Agency (ACOA), Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

© Author(s) 2015. Artículo firmado por 24 autores. This work is distributed under the Creative Commons Attribution 3.0 License. This study is based on discussions held during the joint workshop of the PAGES 2k network and PAST2k-PMIP Integrated analyses of reconstructions and multimodel simulations for the past two millennia, Madrid, Spain, 4-6 November 2013. PAGES and FECYT (FCT-13-6276) are greatly thanked for supporting this workshop. We acknowledge the World Climate Research Programme's Working Group on Coupled Modelling, which is responsible for CMIP. The US Department of Energy's Program for Climate Model Diagnosis and Intercomparison provides coordinating support for CMIP and led the development of software infrastructure in partnership with the Global Organization for Earth System Science Portals. H. Goosse is Research Director with the Fonds National de la Recherche Scientifique (F.R.S.-FNRS, Belgium). This work is supported by the F.R.S.-FNRS and by the Belgian Federal Science Policy Office (Research Programme on Science for a Sustainable Development). C. C. Raible and F. Lehner are supported by the Swiss National Science foundation. P. Yiou is supported by the MILEX project of the Swedish Research Council. J. Gergis is funded by Australian Research Council project DE130100668. O. Bothe was supported by LOCHMES (Leibniz Society), PRIME-II (within DFG INTERDYNAMIK), and CliSAP. L. Fernández Donado was funded by a FPU grant: AP2009-4061. A. Moberg and A. Hind are supported by the Swedish Research Council grants B0334901 and C0592401. G. Hegerl and A. Schurer are supported by the ERC advanced grant TITAN (320691). L. Fernández Donado, E. García Bustamente, and J. F. González Rouco were supported by grants CGL2011-29677-CO2-02 and CGL2014-59644-R. Gabi Hegerl was also supported by a Royal Society Wolfson Research Merit Award and by NCAS. This is LDEO contribution number 7956. N. McKay was funded through the US National Science Foundation (ARC-1107869)., Estimated external radiative forcings, model results, and proxy-based climate reconstructions have been used over the past several decades to improve our understanding of the mechanisms underlying observed climate variability and change over the past millennium. Here, the recent set of temperature reconstructions at the continental-scale generated by the PAGES 2k project and a collection of state-of-the-art model simulations driven by realistic external forcings are jointly analysed. The first aim is to estimate the consistency between model results and reconstructions for each continental-scale region over the time and frequency domains. Secondly, the links between regions are investigated to determine whether reconstructed global-scale covariability patterns are similar to those identified in model simulations. The third aim is to assess the role of external forcings in the observed temperature variations. From a large set of analyses, we conclude that models are in relatively good agreement with temperature reconstructions for Northern Hemisphere regions, particularly in the Arctic. This is likely due to the relatively large amplitude of the externally forced response across northern and high-latitude regions, which results in a clearly detectable signature in both reconstructions and simulations. Conversely, models disagree strongly with the reconstructions in the Southern Hemisphere. Furthermore, the simulations are more regionally coherent than the reconstructions, perhaps due to an underestimation of the magnitude of internal variability in models or to an overestimation of the response to the external forcing in the Southern Hemisphere. Part of the disagreement might also reflect large uncertainties in the reconstructions, specifically in some Southern Hemisphere regions, which are based on fewer palaeoclimate records than in the Northern Hemisphere., Unión Europea. FP7, Fonds de la Recherche Scientifique (F.R.S.-FNRS), Francia, Belgian Federal Science Policy Office (Research Programme on Science for a Sustainable Development), Swiss National Science foundation, MILEX project of the Swedish Research Council, Australian Research Council, LOCHMES (Leibniz Society), Precipitation in the past millennium in Europe (PRIME-II), Cluster of Excellence Integrated Climate System Analysis and Prediction (CliSAP), Formación del Profesorado Universitario (FPU) MECD, España, Swedish Research Council, Royal Society of London for Improving Natural Knowledge, National Centre for Atmospheric Science (NCAS), Reino Unido, US National Science Foundation, Integrated Analysis of Interglacial Climate Dynamics (INTERDYNAMIC), Deutsche Forschungsgemeinschaft (DFG), Alemania, Ministerio de Educación, Cultura y Deporte (MECD), España, Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

© Springer-Verlag 2010. This study received support from MCINN and MARM through the projects TRODIM CGL2007-65891-C05-05/CLI (DB), TRODIM CGL2007-65891-C05-02/CLI (RGH), SPECT-MoRe CGL2008-06558-C02-01/CLI and MOVAC 200800050084028 (JFGR), from IDL-FCUL through the ENAC PTDC/AAC-CLI/103567/2008 project (DB and RMT) and from the EU 6th Framework Program (CIRCE) contract number 036961 (GOCE). Jose Agustin Garcia provided useful comments and suggestions that helped to improve the manuscript. Two anonymous reviewers contributed to improve the final version of this paper., A previously defined automatic method is applied to reanalysis and present-day (1950-1989) forced simulations of the ECHO-G model in order to assess its performance in reproducing atmospheric blocking in the Northern Hemisphere. Unlike previous methodologies, critical parameters and thresholds to estimate blocking occurrence in the model are not calibrated with an observed reference, but objectively derived from the simulated climatology. The choice of model dependent parameters allows for an objective definition of blocking and corrects for some intrinsic model bias, the difference between model and observed thresholds providing a measure of systematic errors in the model. The model captures reasonably the main blocking features (location, amplitude, annual cycle and persistence) found in observations, but reveals a relative southward shift of Eurasian blocks and an overall underestimation of blocking activity, especially over the Euro-Atlantic sector. Blocking underestimation mostly arises from the model inability to generate long persistent blocks with the observed frequency. This error is mainly attributed to a bias in the basic state. The bias pattern consists of excessive zonal winds over the Euro-Atlantic sector and a southward shift at the exit zone of the jet stream extending into in the Eurasian continent, that are more prominent in cold and warm seasons and account for much of Euro-Atlantic and Eurasian blocking errors, respectively. It is shown that other widely used blocking indices or empirical observational thresholds may not give a proper account of the lack of realism in the model as compared with the proposed method. This suggests that in addition to blocking changes that could be ascribed to natural variability processes or climate change signals in the simulated climate, attention should be paid to significant departures in the diagnosis of phenomena that can also arise from an inappropriate adaptation of detection methods to the climate of the m, MCINN, MARM, IDL-FCUL through the ENAC, EU, Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

Copyright 2008 by the American Geophysical Union. This research was supported by the U.S. National Oceanic and Atmospheric Administration by grant NA07OAR4310060 (J.E.S.), by project SPECT (CGL2005-06097/CLI) and the RyC Program, by the Spanish MEC (J.F.G.-R), and by the European project Millennium European Climate (contract 017008 GOCE; E.Z.). LDEO contribution 7194., U.S. National Oceanic and Atmospheric Administration, SPECT, Ministerio de Educación y Ciencia (MEC), España, European project Millennium European Climate, Unión Europea (UE), Programa Ramón y Cajal (MEC), Lamont-Doherty Earth Observatory (LDEO), Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

© 2016 IOP Publishing Ltd. Artículo firmado por 45 autores. Support for PAGES 2k activities is provided by the US and Swiss National Science Foundations, US National Oceanographic and Atmospheric Administration and by the International Geosphere-Biosphere Programme. JPW acknowledges support from the Centre of Climate Dynamics (SKD), Bergen. The work of OB, SW and EZ is part of CLISAP. JL, SW, EZ, JPW, JGN, OB also acknowledge support by the German Science Foundation Project 'Precipitation in the past millennia in Europe-Extension back to Roman times'. MB acknowledges the Catalan Meteorological Survey (SMC), National Programme I + D, Project CGL2011-28255. PD and RB acknowledge support from the Czech Science Foundation project no. GA13-04291S. VK was supported by Russian Science Foundation (grant 14-19-00765) and the Russian Foundation for Humanities (grants 15-07-00012, 15-37-11129). GH and AS are supported by the ERC funded project TITAN (EC-320691). GH was further funded by the Wolfson Foundation and the Royal Society as a Royal Society Wolfson Research Merit Award (WM130060) holder. NY is funded by the LOEWE excellence cluster FACE2-FACE of the Hessen State Ministry of Higher Education, Research and the Arts; HZ acknowledge support from the DFG project AFICHE. Lamont contribution #7961. The reconstructions can be downloaded from the NOAA paleoclimate homepage: www.ncdc.noaa.gov/paleo/study/19600. LFD, EGB and JFGR were supported by grants CGL2011-29677-c02-02 and CGL2014-599644-R. All authors are part of the Euro-Med 2k Consortium., The spatial context is criticalwhen assessing present-day climate anomalies, attributing them to potential forcings and making statements regarding their frequency and severity in a long-term perspective. Recent international initiatives have expanded the number of high-quality proxy-records and developed new statistical reconstruction methods. These advances allow more rigorous regional past temperature reconstructions and, in turn, the possibility of evaluating climate models on policy-relevant, spatiotemporal scales. Here we provide a new proxy-based, annually-resolved, spatial reconstruction of the European summer (June-August) temperature fields back to 755 CE based on Bayesian hierarchical modelling (BHM), together with estimates of the European mean temperature variation since 138 BCE based on BHM and composite-plus-scaling (CPS). Our reconstructions compare well with independent instrumental and proxy-based temperature estimates, but suggest a larger amplitude in summer temperature variability than previously reported. Both CPS and BHM reconstructions indicate that the mean 20th century European summer temperature was not significantly different from some earlier centuries, including the 1st, 2nd, 8th and 10th centuries CE. The 1st century (in BHM also the 10th century) may even have been slightly warmer than the 20th century, but the difference is not statistically significant. Comparing each 50 yr period with the 1951-2000 period reveals a similar pattern. Recent summers, however, have been unusually warm in the context of the last two millennia and there are no 30 yr periods in either reconstruction that exceed the mean average European summer temperature of the last 3 decades (1986-2015 CE). A comparison with an ensemble of climate model simulations suggests that the reconstructed European summer temperature variability over the period 850-2000 CE reflects changes in both internal variability and external forcing on multi-decadal time-scales. For pan-Eur, Unión Europea. FP7, Deutsche Forschungsgemeinschaf = German Science Foundation(DFG), Alemania, Servei de Meteorologia de Catalunya (SMC), Russian Science Foundation, Czech Science Foundation, Russian Foundation for Humanities, Wolfson Foundation, Royal Society, LOEWE excellence cluster FACE2-FACE, Ministerio de Economía y Competitividad (MINECO), España, Centre of Climate Dynamics (SKD), Bergen, National Science Foundation (NSF), EE.UU., Swiss National Science Foundation (SNSF) - SNF, Suiza, US National Oceanographic and Atmospheric Administration, International Geosphere-Biosphere Programme (IGBP), Cluster of Excellence Integrated Climate System Analysis and Prediction (CliSAP), Universidad de Hamburgo, Comisión Interministerial de Ciencia y Tecnología (CICYT), Hessen State Ministry of Higher Education, Research and the Arts, Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

© Author(s) 2012. This work is distributed under the Creative Commons Attribution 3.0 License. This work was funded by the Spanish Ministry of the Environment (project SALVA-SINOVAS, Ref. 200800050083542) and the Spanish Ministry of Science and Technology (projects SPEQMORE-CGL2008-06558-C02-02/CLI and SPEQTRES-CGL2011-29672-C02-02). The authors also gratefully acknowledge funding from the Euro-Mediterranean Institute of Water (IEA). J. J. Gómez Navarro thanks the Spanish Ministry of Education for his Doctoral scholarship (AP2006-04100). The work by E. Zorita is embedded in the EU-Project Millennium European Climate. Thanks to Elena Bustamante for the stimulating discussions., In this study we analyse the role of internal variability in regional climate simulations through a comparison of two regional paleoclimate simulations for the last millennium. They share the same external forcings and model configuration, differing only in the initial condition used to run the driving global model simulation. A comparison of these simulations allows us to study the role of internal variability in climate models at regional scales, and how it affects the long-term evolution of climate variables such as temperature and precipitation. The results indicate that, although temperature is homogeneously sensitive to the effect of external forcings, the evolution of precipitation is more strongly governed by random unpredictable internal dynamics. There are, however, some areas where the role of internal variability is lower than expected, allowing precipitation to respond to the external forcings. In this respect, we explore the underlying physical mechanisms responsible for it. This study identifies areas, depending on the season, in which a direct comparison between model simulations of precipitation and climate reconstructions would be meaningful, but also other areas where good agreement between them should not be expected even if both are perfect., Ministerio de Agricultura, Alimentación y Medio Ambiente (MAGRAMA), España, Ministerio de Ciencia y Tecnología (MCYT), España, Euro-Mediterranean Institute of Water (IEA), Ministerio de Educación, Cultura y Deporte (MECD), España, Millennium project: European climate of the last millennium, Unión Europea (UE), Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

© 2014 American Meteorological Society. The authors thank the European Geosciences Union (EGU) and the Ministerio de Economía y Competitividad (MINECO) of the Spanish government that partially funded the workshop. Special thanks to Mirian Bravo for her assistance with the logistics and administrative work and M. de la Almudena Bailador for preparing the workshop website., Ministerio de Economía y Competitividad (MINECO), European Geosciences Union (EGU), Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

© 2000 American Meteorological Society. The authors thank the Hadley Centre for supplying the model data and two anonymous referees for their helpful comments. Funding was provided by the Comunidad de Madrid, Project CLI97- 0341-c0301, and the Ramón Areces Foundation., The lowest spatial scale at which current climate models are considered to be skillful is on the order of 1000 km because of resolution and computer capabilities. The estimation of the regional changes caused by anthropogenic emissions of greenhouse gases and aerosols therefore is problematic. Here a statistical downscaling scheme is used to study the relationship between large-scale sea lever pressure and regional precipitation in southwestern Europe, both in observed data and in outputs from a general circulation model (GCM) forced with increasing levers of greenhouse gases and sulfate aerosols. The results indicate that the GCM does reproduce the main aspects of the large- to local-scale coupled variability. Furthermore, these large- to local-scale relationships remain stable in the scenario simulations. The GCM runs predict increases of advection of oceanic air masses to the Iberian Peninsula that will produce a slight decrease of precipitation amounts in the north coast and the opposite effect in the rest of the territory, with values that could reach 10 mm decade^-1 in the south. In the homogenized historical records, the obtained pattern of change is very similar. These results support estimations of future regional trends simulated by the GCM under future emission scenarios., Comunidad de Madrid, Fundación Ramón Areces, Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

© 2012 American Meteorological Society. The authors thank two anonymous reviewers for their insightful comments throughout the review process, and Delia Oppo for her constructive feedback on an early draft of this manuscript. KBK gratefully acknowledges support from the WHOI Ocean and Climate Change Institute (OCCI). JES and RS were supported by NOAA's Climate Variability and Predictability Program (Award NA10OAR431037). We acknowledge the modeling groups, the Program for Climate Model Diagnosis and Intercomparison (PCMDI), and the WCRP's Working Group on Coupled Modelling (WGCM) for their roles in making available the WCRP CMIP3 multimodel dataset. Support of this dataset is provided by the Office of Science, U.S. Department of Energy. Thanks especially to NOAA GFDL for providing the millennial simulation output of the GFDL CM2.1., Internal climate variability at the centennial time scale is investigated using long control integrations from three state-of-the-art global coupled general circulation models. In the absence of external forcing, all three models produce centennial variability in the mean zonal sea surface temperature (SST) and sea level pressure (SLP) gradients in the equatorial Pacific with counterparts in the extratropics. The centennial pattern in the tropical Pacific is dissimilar to that of the interannual El Nino-Southern Oscillation (ENSO), in that the most prominent expression in temperature is found beneath the surface of the western Pacific warm pool. Some global repercussions nevertheless are analogous, such as a hemispherically symmetric atmospheric wave pattern of alternating highs and lows. Centennial variability in western equatorial Pacific SST is a result of the strong asymmetry of interannual ocean heat content anomalies, while the eastern equatorial Pacific exhibits a lagged, Bjerknes-like response to temperature and convection in the west. The extratropical counterpart is shown to be a flux-driven response to the hemispherically symmetric circulation anomalies emanating from the tropical Pacific. Significant centennial-length trends in the zonal SST and SLP gradients rivaling those estimated from observations and model simulations forced with increasing CO_2 appear to be inherent features of the internal climate dynamics simulated by all three models. Unforced variability and trends on the centennial time scale therefore need to be addressed in estimated uncertainties, beyond more traditional signal-to-noise estimates that do not account for natural variability on the centennial time scale., WHOI Ocean and Climate Change Institute (OCCI), National Oceanic and Atmospheric Administration (NOAA), Open Cloud Computing Interface (OCCI), Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

© Author(s) 2014. This work is distributed under the Creative Commons Attribution 3.0 License. This work is supported by the Sinergia project FUPSOL funded by the Swiss National Science Foundation. 20th Century Reanalysis data is provided by the NOAA/OAR/ESRL PSD, Boulder, Colorado, USA (from their website at http://www.esrl.noaa.gov/psd/). The CCSM3 simulations are performed on the super computing architecture of the Swiss National Supercomputing Centre (CSCS). LFD and JFGR were supported by CGL 2011-29677-602-02, CGL 2011-29672-602-01, and the FPU grant AP2009-4061., Atmospheric circulation modes are important concepts in understanding the variability of atmospheric dynamics. Assuming their spatial patterns to be fixed, such modes are often described by simple indices from rather short observational data sets. The increasing length of reanalysis products allows these concepts and assumptions to be scrutinised. Here we investigate the stability of spatial patterns of Northern Hemisphere teleconnections by using the Twentieth Century Reanalysis as well as several control and transient millennium-scale simulations with coupled models. The observed and simulated centre of action of the two major teleconnection patterns, the North Atlantic Oscillation (NAO) and to some extent the Pacific North American (PNA), are not stable in time. The currently observed dipole pattern of the NAO, its centre of action over Iceland and the Azores, split into a north-south dipole pattern in the western Atlantic with a wave train pattern in the eastern part, connecting the British Isles with West Greenland and the eastern Mediterranean during the period 1940-1969 AD. The PNA centres of action over Canada are shifted southwards and over Florida into the Gulf of Mexico during the period 1915-1944 AD. The analysis further shows that shifts in the centres of action of either teleconnection pattern are not related to changes in the external forcing applied in transient simulations of the last millennium. Such shifts in their centres of action are accompanied by changes in the relation of local precipitation and temperature with the overlying atmospheric mode. These findings further undermine the assumption of stationarity between local climate/proxy variability and large-scale dynamics inherent when using proxy-based reconstructions of atmospheric modes, and call for a more robust understanding of atmospheric variability on decadal timescales., project FUPSOL (Future and Past Solar Influence on the Terrestrial Climate), SNSF, Programa FPU (Formación de Profesorado Universitario), MECD, Swiss National Science Foundation (SNSF), Ministerio de Educación, Cultura y Deporte (MECD), España, Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

© 2010 American Meteorological Society. This project was accomplished within the collaboration agreement 091153 between UCM and CIEMAT, and it was partially funded by projects CGL2005-06966-C07/CLI and PSE-120000-2008-9 We thank the Navarra Government for providing us with the wind dataset used in this study. We also like to thank the reviewers for their helpful comments., Meteorological data of good quality arc important for understanding both global and regional climates In this respect, great efforts have been made to evaluate temperature- and precipitation-related records This study summarizes the evaluations made to date of the quality of wind speed and direction records acquired at 41 automated weather stations in the northeast of the Iberian Peninsula Observations were acquired from 1992 to 2005 at a temporal resolution of 10 and 30 min A quality assurance system was imposed to select) the records for 1) manipulation errors associated with storage and management of the data. 2) consistency limits to to ensure that observations ale within their natural limits of variation, and 3) temporal consistency to assess abnormally low/high variations in the individual time series In addition. the most important biases of the dataset are analyzed and corrected wherever possible A total of 1 8% wind speed and 3 7% wind direction records was assumed invalid. pointing to specific problems in wind measurement The study not only tiles to contribute to the science with the creation of a wind damsel of unmoved quality. but it also reports on potential errors that could be plc:sent in other wind datasets, Universidad Complutense de Madrid (UCM), Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

© Author(s) 2012. This work is distributed under the Creative Commons Attribution 3.0 License. We thank J.-C. Mareschal and the anonymous reviewer for their efforts, which improved this article considerably. VR was funded by the Ramón y Cajal Program (Gobierno de España, Ministerio de Educación, Cultura y Deporte), project CCG10-UCM/ESP-5070 (Comunidad de Madrid/UCM), and project CGL2011-29672-C02-01 (Gobierno de España, Ministerio de Economía y Competitividad)., The investigation of observed borehole temperatures has proved to be a valuable tool for the reconstruction of ground surface temperature histories. However, there are still many open questions concerning the significance and accuracy of the reconstructions from these data. In particular, the temperature signal of the warming after the Last Glacial Maximum is still present in borehole temperature profiles. It is shown here that this signal also influences the relatively shallow boreholes used in current paleoclimate inversions to estimate temperature changes in the last centuries by producing errors in the determination of the steady state geothermal gradient. However, the impact on estimates of past temperature changes is weaker. For deeper boreholes, the curvature of the long-term signal is significant. A correction based on simple assumptions about glacial-interglacial temperature changes shows promising results, improving the extraction of millennial scale signals. The same procedure may help when comparing observed borehole temperature profiles with the results from numerical climate models., Programa Ramón y Cajal (MECD), Comunidad de Madrid, Ministerio de Economía y Competitividad (MINECO), España, Ministerio de Educación, Cultura y Deporte (MECD), España, Universidad Complutense de Madrid (UCM), Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

© 2013 American Meteorological Society. SC, JES, and RS are supported by the NOAA Award Global Decadal Hydroclimate Variability and Change (NA10OAR431037). RS was also supported by NSF Award ATM09-02716 and NOAA Award NA08-OAR4320912. BIC was supported by the NSF Award North American Megadroughts: Atmosphere-Ocean Forcing and Landscape Response from the Medieval Period to the Near-Term Greenhouse Future (ATM-0902716). JFGR was supported by MMAMRM-200800050084028//200800050083542, MCIN-CGL2008-06558-C02-01, and UCM/921407. Cross-wavelet and wavelet coherence software was provided by A. Grinsted., Simulated hydroclimate variability in millennium-length forced transient and control simulations from the ECHAM and the global Hamburg Ocean Primitive Equation (ECHO-G) coupled atmosphere-ocean general circulation model (AOGCM) is analyzed and compared to 1000 years of reconstructed Palmer drought severity index (PDSI) variability from the North American Drought Atlas (NADA). The ability of the model to simulate megadroughts in the North American southwest is evaluated. (NASW: 25º-42.5ºN, 125º-105ºW). Megadroughts in the ECHO-G AOGCM are found to be similar in duration and magnitude to those estimated from the NADA. The droughts in the forced simulation are not, however, temporally synchronous with those in the paleoclimate record, nor are there significant differences between the drought features simulated in the forced and control runs. These results indicate that model-simulated megadroughts can result from internal variability of the modeled climate system rather than as a response to changes in exogenous forcings. Although the ECHO-G AOGCM is capable of simulating megadroughts through persistent La Nina-like conditions in the tropical Pacific, other mechanisms can produce similarly extreme NASW moisture anomalies in the model. In particular, the lack of low-frequency coherence between NASW soil moisture and simulated modes of climate variability like the El Nino-Southern Oscillation, Pacific decadal oscillation, and Atlantic multidecadal oscillation during identified drought periods suggests that stochastic atmospheric variability can contribute significantly to the occurrence of simulated megadroughts in the NASW. These findings indicate that either an expanded paradigm is needed to understand multidecadal hydroclimate variability in the NASW or AOGCMs may incorrectly simulate the strength and/or dynamics of the connection between NASW hydroclimate variability and the tropical Pacific., Award Global Decadal Hydroclimate Variability and Change (NOAA), National Science Foundation (NSF), National Oceanic and Atmospheric Administration (NOAA), EE.UU., NSF Award North American Megadroughts, Universidad Complutense de Madrid (UCM), Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

Copyright 2012 by the American Geophysical Union. This study received support from the Spanish Ministry of Environment (projects ESCENA, reference 20080050084265, and SALVA-SINOBAS), the Spanish Ministry of Science and Technology (project INVENTO-CGL2005-06966-C07-04/CLI), the Regional Agency for Science and Technology of Murcia (Fundación Séneca, reference 00619/PI/04) and the "Instituto Euromediterráneo del Agua". P. Jiménez Guerrero thanks the Ramón y Cajal Program of the Spanish Ministry of Science and Innovation. J. J. Gómez Navarro thanks the Spanish Ministry of Education for his Doctoral scholarship (AP2006-04100). Finally, the authors gratefully acknowledge the contribution of anonymous reviewers which helped us to improve the quality and clarity of the manuscript., The importance of land-surface processes within Regional Climate Models for accurately reproducing the present-day climate is well known. However, their role when projecting future climate is still poorly reported. Hence, this work assesses the influence of the land-surface processes, particularly the contribution of soil moisture, when projecting future changes for temperature, precipitation and wind over a complex area as the Iberian Peninsula, which, in addition, shows great sensitivity to climate change. The main signals are found for the summer season, when the results indicate a strengthening in the increases projected for both mean temperature and temperature variability as a consequence of the future intensification of the positive soil moisture-temperature feedback. The more severe warming over the inner dry Iberian Peninsula further implies an intensification of the Iberian thermal low and, thus, of the cyclonic circulation. Furthermore, the land-atmosphere coupling leads to the projection of a wider future daily temperature range, since maximum temperatures are more affected than minima, a feature absent in non-coupled simulations. Regarding variability, the areas where the land-atmosphere coupling introduces larger changes are those where the reduction in the soil moisture content is more dramatic in future simulations, i.e., the so-called transitional zones. As regards precipitation, weaker positive signals for convective precipitation and more intense negative signals for non-convective precipitation are obtained as a result of the soil moisture-atmosphere interactions. These results highlight the crucial contribution of soil moisture to climate change projections and suggest its plausible key role for future projections of extreme events., Ministerio de Medio Ambiente y Medio Rural y Marino, España, Ministerio de Ciencia y Tecnología (MCYT), España, Agencia Regional de Ciencia y Tecnología de la Región de Murcia, Instituto Euromediterráneo del Agua, Ministerio de Educación, Cultura y Deporte (MECD), España, Ministerio de Ciencia e Innovación ((MCI), España, Fundación Séneca, Murcia, Proyecto ESCENA, Proyecto SALVÁ-SINOBAS, Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

Copyright 2010 by the American Geophysical Union. This research was supported by grants from the Canadian Foundation for Climate and Atmospheric Sciences (CFCAS), the Natural Sciences and Engineering Research Council of Canada (NSERC), and the Atlantic Innovation Fund (ACOA-AIF). A. H. M. D. and M. B. S. are grateful for their support received from NSERC as a PGS-M and a PGS-D respectively. JFGR acknowledges support from projects CGL2008-06558-C02-01, MMARM-200800050084028 and MMARM-20080005008354., Heat fluxes in the continental subsurface were estimated from general circulation model (GCM) simulations of the climate of the last millennium and compared to those obtained from subsurface geothermal data. Since GCMs have bottom boundary conditions (BBCs) that are less than 10 m deep and thus may be thermodynamically restricted in the continental subsurface, we used an idealized land surface model (LSM) with a very deep BBC to estimate the potential for realistic subsurface heat storage in the absence of bottom boundary constraints. Results indicate that there is good agreement between observed fluxes and GCM simulated fluxes for the 1780-1980 period when the GCM simulated temperatures are coupled to the LSM with deep BBC. These results emphasize the importance of placing a deep BBC in GCM soil components for the proper simulation of the overall continental heat budget. In addition, the agreement between the LSM surface fluxes and the borehole temperature reconstructed fluxes lends additional support to the overall quality of the GCM (ECHO-G) paleoclimatic simulations., Canadian Foundation for Climate and Atmospheric Sciences (CFCAS), Natural Sciences and Engineering Research Council of Canada (NSERC), Atlantic Innovation Fund (ACOA - AIF), Ministerio de Medio Ambiente, Medio Rural y Marino de España (Ministerio de Medio Ambiente, Medio Rural y Marino de España (MARM), España, Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

Copyright 2007 by the American Geophysical Union. This study was financially supported by projects REN2002-04584-C04-01-CLI, REN-2002-04584-C04-04-CLI, CGL2005-06966-C07-04/CLI and CGL2005-06966-C07-05/CLI of the Spanish Ministry of Science and Technology. Jesús Fernández received support from the Department of Education, Universities and Research of the Basque Autonomous Government through grant BFI04.52. J. Sáenz received support by the research groups’ support program, project 9/UPV 00060.310-15343/2003, University of the Basque Country. The gridded precipitation and temperature data were supplied by the Climate Impacts LINK Project (UK Department of the Environment Contract EPG 1/1/16) on behalf of the Climatic Research Unit, University of East Anglia. The boundary conditions were downloaded from the NCEP/NCAR Web server. The National Institutes of Meteorology of Spain and Portugal provided access to daily records of temperature and precipitation at several sites. Other surface and boundary data were provided by the MARS system of the ECMWF. The authors thank the Pennsylvania State University/National Center for Atmospheric Research numerical model home page for making the MM5 model publicly available. Authors made extensive use of the Generic Mapping Tools software [Wessel and Smith, 1991]. GTOPO30 topography data are distributed by the Land Processes Distributed Active Archive Center (LP DAAC), located at the U.S. Geological Survey’s EROS Data Center http://LPDAAC.usgs.gov. We appreciate the comments on the manuscript made by Jimy Dudhia. The comments by three anonymous reviewers have also improved the final version of this manuscript., We present an analysis of the sensitivity to different physical parameterizations of a high-resolution simulation of the MM5 mesoscale model over the Iberian Peninsula. Several (16) 5-year runs of the MM5 model with varying parameterizations of microphysics, cumulus, planetary boundary layer and longwave radiation have been carried out. The results have been extensively compared with observational precipitation and surface temperature data. The parameterization uncertainty has also been compared with that related to the boundary conditions and the varying observational data sets. The annual cycles of precipitation and surface temperature are well reproduced. The summer season presents the largest deviations, with a 5 K cold bias in the southeast and noticeable precipitation errors over mountain areas. The cold bias seems to be related to the surface, probably because of the excessive moisture availability of the five-layer soil scheme used. No parameterization combination was found to perform best in simulating both precipitation and surface temperature in every season and subregion. The Kain-Fritsch cumulus scheme was found to produce unrealistically high summer precipitation. The longwave radiation parameterizations tested were found to have little impact on our target variables. Other factors, such as the choice of boundary conditions, have an impact on the results as large as the selection of parameterizations. The range of variability in the MM5 physics ensemble is of the same order of magnitude as the observational uncertainty, except in summer, when it is larger and probably related to the inaccuracy of the model to reproduce the summer precipitation over the area., Mininsterio de Ciencia y Tecnolgía (MCYT), España, Departamento de Educación, Política Lingüística y Cultura (Gobierno Vasco), Universidad del País Vasco / Euskal Herriko Unibertsitatea (UPV / EHU), Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

© Author(s) 2009. This work is distributed under the Creative Commons Attribution 3.0 License. This research was supported: in Spain by project SPECT (CGL2005-06097/CLI) and the Ramón y Cajal Program of the Ministerio de Educación y Ciencia (MEC) and project PalMA (CCG07-UCM/ESP-3045) by the Comunidad Autónoma de Madrid and the Universidad Complutense de Madrid; in Canada by the Natural Sciences and Engineering Research Council of Canada (NSERC), the Canadian Foundation for Climate and Atmospheric Sciences (CFCAS) and the Atlantic Innovation Fund (AIF-ACOACanada); and in Germany by the EU project Millennium European Climate. The authors thank Vladimir Cermak and two anonymous reviewers for their comments and suggestions. Also we appreciate the contributions from Volker Rath and Jason Smerdon, editors of this special volume., Progress in understanding climate variability through the last millennium leans on simulation and reconstruction efforts. Exercises blending both approaches present a great potential for answering questions relevant both for the simulation and reconstruction of past climate, and depend on the specific peculiarities of proxies and methods involved in climate reconstructions, as well as on the realism and limitations of model simulations. This paper explores research specifically related to paleoclimate modeling and borehole climatology as a branch of climate reconstruction that has contributed significantly to our knowledge of the low frequency climate evolution during the last five centuries. The text flows around three main issues that group most of the interaction between model and geothermal efforts: the use of models as a validation tool for borehole climate reconstructions; comparison of geothermal information and model simulations as a means of either model validation or inference about past climate; and implications of the degree of realism on simulating subsurface climate on estimations of future climate change. The use of multi-centennial simulations as a surrogate reality for past climate suggests that within the simplified reality of climate models, methods and assumptions in borehole reconstructions deliver a consistent picture of past climate evolution at long time scales. Comparison of model simulations and borehole profiles indicate that borehole temperatures are responding to past external forcing and that more realism in the development of the soil model components in climate models is desirable. Such an improved degree of realism is important for the simulation of subsurface climate and air-ground interaction; results indicate it could also be crucial for simulating the adequate energy balance within climate change scenario experiments., SPECT, Programa Ramón y Cajal (Ministerio de Educación y Ciencia, MEC), Comunidad de Madrid, Universidad Complutense de Madrid (UCM), Natural Sciences and Engineering Research Council of Canada (NSERC), Canadian Foundation for Climate and Atmospheric Sciences (CFCAS), Atlantic Innovation Fund (AIF-ACOACanada), Unión Europea (UE), Proyecto PalMA, Project Millennium European Climate (UE), Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

© 2011 American Meteorological Society. The National Center for Atmospheric Research is sponsored by the National Science Foundation.We thank the Navarra government and the ECMWF for providing us with the datasets used in this study. This investigation was partially supported by Projects CGL-2008-05093/CLI and PSE-120000-2008-9 and was accomplished within the Collaboration Agreement 09/490 between CIEMAT and NCAR as well as the Collaboration Agreement 09/153 between CIEMAT and UCM. We also thank the reviewers for their helpful comments., Variations in the diurnal wind pattern associated with heat waves and drought conditions are investigated climatologically at a regional level (northeast of the Iberian Peninsula). The study, based on high-density observational evidence and fine spatial-scale mesoscale modeling for the 1992-2004 period, shows that wind speed can decrease up to 22% under situations characterized by extremely high temperatures and severe drought, such as the European summer of 2003. By examining the role of the different atmospheric scales of motion that determine the wind diurnal variability, it is found that the 2003 synoptic conditions are the main driver for changes in the wind speed field. In turn, these changes are modulated by mesoscale circulations influenced by the soil moisture availability. The results have implications for broad regional modeling studies of current climate and climate change simulations in as much as the study demonstrates that a correct representation of local soil moisture conditions impacts atmospheric circulation and therefore the regional climate state., National Science Foundation, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), España, National Center for Atmospheric Research (NCAR), EE.UU., Universidad Complutense de Madrid (UCM), Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

© 2013. American Geophysical Union. All Rights Reserved. This investigation was partially supported by projects CGL-2008-05093/CLI and CGL-2011-29677-C02 and was accomplished within the collaboration agreement 09/490 between CIEMAT and NCAR as well as the collaboration agreement 09/153 between CIEMAT and UCM. NCAR is sponsored by the National Science Foundation. We would like to thank the Navarra government and the ECMWF for facilitating the access to its data sets. We also would like to thank the reviewers for their constructive comments which helped to increase the value of the contents of the manuscript., The performance of the Weather Research and Forecasting (WRF) model to reproduce the surface wind circulations over complex terrain is examined. The atmospheric evolution is simulated using two versions of the WRF model during an over 13year period (1992 to 2005) over a complex terrain region located in the northeast of the Iberian Peninsula. A high horizontal resolution of 2km is used to provide an accurate representation of the terrain features. The multiyear evaluation focuses on the analysis of the accuracy displayed by the WRF simulations to reproduce the wind field of the six typical wind patterns (WPs) identified over the area in a previous observational work. Each pattern contains a high number of days which allows one to reach solid conclusions regarding the model performance. The accuracy of the simulations to reproduce the wind field under representative synoptic situations, or pressure patterns (PPs), of the Iberian Peninsula is also inspected in order to diagnose errors as a function of the large-scale situation. The evaluation is accomplished using daily averages in order to inspect the ability of WRF to reproduce the surface flow as a result of the interaction between the synoptic scale and the regional topography. Results indicate that model errors can originate from problems in the initial and lateral boundary conditions, misrepresentations at the synoptic scale, or the realism of the topographic features., Ministerio de Economía y Competitividad (MINECO), Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), España, National Center for Atmospheric Research (NCAR), Universidad Complutense de Madrid (UCM), National Science Foundation (NSF), Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

Copyright 2005 by the American Geophysical Union. We thank the two reviewers and Drs. D. Bray, J. Luterbacher, M. Montoya and E. Xoplaki for their comments and proof reading of this manuscript. This work was partially funded by the DEKLIM Program of the German BMBF, the EU project SO&P and by the project REN-2000-0786Cli of the Spanish CICYT., The spatial patterns of surface air-temperature variations in the period 1000 to 2100, simulated with the ECHO-G atmosphere-ocean coupled model, are analyzed. The model was driven by solar, volcanic and greenhouse gas forcing. The leading mode of temperature variability in the preindustrial period represents an almost global coherent variation of temperatures, with larger amplitudes over the continents and Northern Hemisphere. This mode also describes a large part of the spatial structure of the warming simulated in the 21st century. However, in the 21st century, regional departures from this spatial structure are also present and can be ascribed to atmospheric circulation responses to anthropogenic forcing in the last decades of the 21st century., DEKLIM Program (BMBF), Alemania, Unión Europea (UE), Comisión Interministerial de Ciencia y Tecnología (CICYT), España, Startseite des Webauftritts des Bundesministeriums für Bildung und Forschung (BMBF), Alemania, Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

© by Gebrüder Borntraeger 2010. Lund Regional-Scale Climate Modelling Workshop (2nd. 2009. Lund, Sweden). This work was funded by the Spanish Ministry of the Environment (project ESCENA, Ref. 20080050084265) and the Spanish Ministry of Science and Technology (project SPECMORE-CGL2008-06558-C02-02/CLI). The authors also gratefully acknowledge funding from the Euro-Mediterranean Institute of Water (IEA) and the Regional Agency for Science and Technology of Murcia (Fundación Séneca, Ref. 00619/PI/04 and 11047/EE1/09). J.J. GÓMEZ NAVARRO thanks the Spanish Ministry of Education for his Doctoral scholarship (AP2006- 04100). Thanks to the Max Planck Institute and DKRZ for providing the access and computational support necessary to get the GCM simulation data employed in this work. Also thanks to the professor Volker RATH for translating the abstract into German., A set of four regional climate change projections over the Iberian Peninsula has been performed. Simulations were driven by two General Circulation Models (consisting of two versions of the same atmospheric model coupled to two different ocean models) under two different SRES scenario. The XXI century has been simulated following a full-transient approach with a climate version of the mesoscale model MM5. An Empirical Orthogonal Function analysis (EOF) is applied to the monthly mean series of daily maximum and minimum 2-metre temperature to extract the warming signal. The first EOF is able to capture the spatial structure of the warming. The obtained warming patterns are fairly dependent on the month, but hardly change with the tested scenarios and GCM versions. Their shapes are related to geographical parameters, such as distance to the sea and orography. The main differences among simulations mostly concern the temporal evolution of the warming. The temperature trend is stronger for maximum temperatures and depends on the scenario and the driving GCM. This asymmetry, as well as the different warming rates in summer and winter, leads to a continentalization of the climate over the IP., Vier regionale Projektionen des Klimawandels im Bereich der Iberischen Halbinsel werden vorgestellt. Die zu Grunde liegenden numerischen Simulationen wurden durch die Ergebnisse aus je zwei unterschiedlichen globalen Zirkulationsmodellen (GCM) angetrieben, welche jeweils das identische Atmosphärenmodul mit unterschiedlichen Ozeanmodulen kombinieren. Dabei wurden für zwei SRES-Szenarios behandelt. Das XXI. Jahrhundert wurde zeitabhängig mit einer klimatauglichen Version des ursprünglich mesoskaligen MM5-Modells simuliert. Die resultierenden Zeitreihen der täglichen Maximaltemperatur und Minimaltemperatur in 2 m Höhe wurden mit der Methode der empirischen orthogonalen Funktionen (EOF) analysiert, um das Signal der Erwärmung zu extrahieren. Die erste EOF gibt die räumliche Struktur des Erwärmungsmusters wieder. Diese Muster sind deutlich monatsabhängig, unterscheiden sich jedoch kaum für die beiden Szenarios und die Versionen des antreibenden GCM. Ihre Eigenschaften hängen mit geographischen Parametern zusammen, wie zum Beispiel dem Abstand zur Küste und der Orographie. Die wichtigsten Unterschiede zwischen den Simulationen betreffen die zeitliche Entwicklung der Erwärmung. Dieser Trend ist ausgeprägter für die Maximaltemperaturen, und hängt von den Szenarios und den antreibenden GCM ab. Die zunehmenden täglichen Differenzen in Kombination mit den unterschiedlichen Erwärmungsraten in Sommer und Winter bedeuten eine Kontinentalisierung des Klimas der Iberischen Halbinsel., Ministerio de Medio Ambiente (MMA), España, Ministerio de Ciencia y Tecnología (MCYT), España, Euro-Mediterranean Institute of Water (IEA), Fundación Séneca (Agencia de Ciencia y Tecnología de la Región de Murcia), Ministerio de Educación, Cultura y Deporte (MECD), España, Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

© 2008 American Meteorological Society. We thank the Sección de Evaluación de Recursos Agrarios del Departamento de Agricultura, Ganadería y Alimentación of the Navarra Government for providing us with the wind dataset used in this study and the ECMWF for the free access to the ERA-40 data. We also thank Drs. M. Montoya and C. Raible for useful discussions, suggestions, and comments during this work, as well as Prof. M. Cornide for providing a first version of the code to calculate the spectral densities. The authors are indebted to the three reviewers for their comments, which helped to improve the quality of the original manuscript considerably. This work was partially funded by Project CGL2005- 06966-C07/CLI. JFGR was supported by a Ramón y Cajal fellowship., Daily wind variability in the Comunidad Foral de Navarra in northern Spain was studied using wind observations at 35 locations to derive subregions with homogeneous temporal variability. Two different methodologies based on principal component analysis were used to regionalize: 1) cluster analysis and 2) the rotation of the selected principal components. Both methodologies produce similar results and lead to regions that are in general agreement with the topographic features of the terrain. The meridional wind variability is similar in all subregions, whereas zonal wind variability is responsible for differences between them. The spectral analysis of wind variability within each subregion reveals a dominant annual cycle and the varying presence of higher-frequency contributions in the subregions. The valley subregions tend to present more variability at high frequencies than do higher-altitude sites. Last, the influence of large-scale dynamics on regional wind variability is explored by studying connections between wind in each subregion and sea level pressure fields. The results of this work contribute to the characterization of wind variability in a complex terrain region and constitute a framework for the validation of mesoscale model wind simulations over the region., Programa Ramón y Cajal (MEC), Ministerio de Educación y Ciencia (MEC), España, Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

© Author(s) 2013. LFD was funded by a FPU grant: AP2009-4061. LFD and JFGR acknowledge project grants UCM-921407, CGL2008-06558-C02-02/CLI, CGL2011-29672-C02-02, 200800050083542 and 200800050084028. CCR acknowledges SNF-FUPSOL. DB acknowledges projects CGL2008-05968-C02-01 and ENAC-PTDC/AAC-CLI/103567/2008. JL acknowledges EU/FP7-ACQWA-NO212250, DFG-PRIME1,2, LU1608/1-1/AOBJ:568460 and LU1608/2-1/AOBJ:575150. JS, DS and PY acknowledge the ANR ESCARSEL grant., Understanding natural climate variability and its driving factors is crucial to assessing future climate change. Therefore, comparing proxy-based climate reconstructions with forcing factors as well as comparing these with paleo-climate model simulations is key to gaining insights into the relative roles of internal versus forced variability. A review of the state of modelling of the climate of the last millennium prior to the CMIP5-PMIP3 (Coupled Model Intercomparison Project Phase 5-Paleoclimate Modelling Intercomparison Project Phase 3) coordinated effort is presented and compared to the available temperature reconstructions. Simulations and reconstructions broadly agree on reproducing the major temperature changes and suggest an overall linear response to external forcing on multidecadal or longer timescales. Internal variability is found to have an important influence at hemispheric and global scales. The spatial distribution of simulated temperature changes during the transition from the Medieval Climate Anomaly to the Little Ice Age disagrees with that found in the reconstructions. Thus, either internal variability is a possible major player in shaping temperature changes through the millennium or the model simulations have problems realistically representing the response pattern to external forcing. A last millennium transient climate response (LMTCR) is defined to provide a quantitative framework for analysing the consistency between simulated and reconstructed climate. Beyond an overall agreement between simulated and reconstructed LMTCR ranges, this analysis is able to single out specific discrepancies between some reconstructions and the ensemble of simulations. The disagreement is found in the cases where the reconstructions show reduced covariability with external forcings or when they present high rates of temperature change., FPU, SNF-FUPSOL, ANR ESCARSEL, Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

Copyright 2006 by the American Geophysical Union. This research was funded by the Natural Sciences and Engineering Research Council of Canada (NSERC), the Atlantic Innovation Fund (AIF), and project CGL2005-06097 of the Spanish MEC. Part of this work was carried out while JFGR was a James Chair Professor at STFX., General Circulation Models (GCMs) used to distinguish anthropogenic forcing of the Earth's past climate from its natural variability need to be validated by observations. The GCM ECHO-g was used to produce three millennial simulations of the Earth's climate. Two simulations include changes in anthropogenic and natural external forcing factors through the last millennium, differing only in their initial conditions, and a control run with constant external forcing representing internal variability. Since the ground contains a record of long-term trends in SAT, we use borehole temperatures in Canada, grouped into regions, as a record of past climate. The regional average SATs from ECHO-g were used to solve the forward subsurface thermal profile, and compared with the underground temperature anomalies observed at each region. In all cases simulated subsurface anomalies from the forced simulations are in better agreement with observations than those from the control simulation., Natural Sciences and Engineering Research Council of Canada (NSERC), Atlantic Innovation Fund (AIF), Ministerio de Educación y Ciencia (MEC), España, Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

Copyright 2006 by the American Geophysical Union. This research was funded by in Canada by NSERC, CFCAS, AIF, and project REN2002-04584-C04-04CLI and CGL2005-06097 of the Spanish MEC. B. Quinn helped us at the early stages of this work. We thank R. N. Harris and an anonymous reviewer helpful comments., Variations in the Earth's surface energy balance are recorded in the subsurface as perturbations of the steady state thermal field. Here we invert 558 temperature-depth profiles in the Northern Hemisphere (NH), in order to estimate the energy balance history at the continental surface from heat flux anomalies in the subsurface. The heat gain is spatially variable and does not appear to have been persistent for the last 200 years at all locations, but overall continental areas have absorbed energy in the last 50 years. Results indicate a mean surface heat flux of 20.6 mWm^-2 over the last 200 years. The total heat absorbed by the ground is 4.8 x 10^21 J and 13.3 x 10^2 J for the last 50 and 200 years respectively. We suggest that our results may be useful for state-of-the-art General Circulation Model (GCM) validation and for land-surface coupling schemes., Natural Sciences and Engineering Research Council of Canada (NSERC), Canadá, Canadian Foundation for Climate and Atmospheric Sciences (CFCAS), Atlantic Innovation Fund (AIF), Canadá, Ministerio de Educación y Ciencia (MEC), España, Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

© 2001 American Meteorological Society. This work was supported by Project Number CLI97-0558, Comunidad de Madrid, and Fundación Ramón Areces. The authors also thank P. Brandt, P. Cuesta, M. Widmann, and E. Zorita for their comments on the original version of the manuscript. We thank also F. Zwiers and the two anonymous reviewers for their valuable comments and suggestions., A quality control process involving outliers processing, homogenization, and interpolation has been applied to 95 monthly precipitation series in the Iberian Peninsula, southern France, and northern Africa during the period 1899- 1989. A detailed description of the procedure results is provided and the impact of adjustments on trend estimation is discussed. Outliers have been censored by trimming extreme values. Homogeneity adjustments have been developed by applying the Standard Normal Homogeneity Test in combination with an objective methodology to select reference series. The spatial distribution of outliers indicates that they are due to climate variability rather than measurement errors. After carrying out the homogeneity procedure, 40% of the series were found to be homogeneous, 49.5% became homogeneous after one adjustment, and 9.5% after two adjustments. About 30% of the inhomogeneities could be traced to information in the scarce history files. It is shown that these data present severe homogeneity problems and that applying outliers and homogeneity adjustments greatly changes the patterns of trends for this area., Comunidad de Madrid, Fundación Ramón Areces, Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

Copyright 2007 by the American Geophysical Union. This research was funded by the Natural Sciences and Engineering Research Council of Canada (NSERC), the Atlantic Innovation Fund (AIF-ACOA), project CGL2005-06097 of the Spanish MEC, NSF grants from the Office of Polar Programs (OPP- 0436118), the division of Environmental Biology (Arctic LTER Project), a Biocomplexity Award (ATM-0439620), and by NASA’s Global Modeling and Analysis Program RTOP 622-24-47. J. E. Smerdon was supported by a Lamont-Doherty Postdoctoral Fellowship and by CICAR grant NA03OAR4320179 P 20A. JFGR was supported by a Ramón y Cajal contract., [1] A one-dimensional soil model is used to estimate the influence of the position of the bottom boundary condition on heat storage calculations in land-surface components of General Circulation Models (GCMs). It is shown that shallow boundary conditions reduce the capacity of the global continental subsurface to store heat by as much as 1.0 x 10^23 Joules during a 110-year simulation with a 10 m bottom boundary. The calculations are relevant for GCM projections that employ land-surface components with shallow bottom boundary conditions, typically ranging between 3 to 10 m. These shallow boundary conditions preclude a large amount of heat from being stored in the terrestrial subsurface, possibly allocating heat to other parts of the simulated climate system. The results show that climate models of any complexity should consider the potential for subsurface heat storage whenever choosing a bottom boundary condition in simulations of future climate change., Natural Sciences and Engineering Research Council of Canada (NSERC), Atlantic Innovation Fund (AIF-ACOA), Ministerio de Educación y Ciencia (MEC), España, Office of Polar Programs (NFS), Environmental Biology, Biocomplexity Award, NASA’s Global Modeling and Analysis Program, Lamont-Doherty Postdoctoral Fellowship, CICAR grant, Programa Ramón y Cajal (MEC), National Science Foundation (NFS), Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

© Author(s) 2013. This work is distributed under the Creative Commons Attribution 3.0 License. This work has been possible thanks to the funding by the MCINN projects CGL2005-06097 and CGL2008-06558-C02-C01/CLI, and the MARM project 200800050084028. The manuscript was significantly improved thanks to helpful and insightful comments of four anonymous reviewers. We are grateful to A. Grinsted and S. Jevrejeva for making the MatLab wavelet coherence package and their global sea level reconstructions available, and to A. Kemp for kindly sharing the data from North Carolina with us. We would also like to thank G. Sgubin for interesting discussions and to I. Fast for providing us with the extended FOR1 data.The publication of this article is financed by CNRS-INSU., Studies addressing climate variability during the last millennium generally focus on variables with a direct influence on climate variability, like the fast thermal response to varying radiative forcing, or the large-scale changes in atmospheric dynamics (e. g. North Atlantic Oscillation). The ocean responds to these variations by slowly integrating in depth the upper heat flux changes, thus producing a delayed influence on ocean heat content (OHC) that can later impact low frequency SST (sea surface temperature) variability through reemergence processes. In this study, both the externally and internally driven variations of the OHC during the last millennium are investigated using a set of fully coupled simulations with the ECHO-G (coupled climate model ECHAMA4 and ocean model HOPE-G) atmosphere-ocean general circulation model (AOGCM). When compared to observations for the last 55 yr, the model tends to overestimate the global trends and underestimate the decadal OHC variability. Extending the analysis back to the last one thousand years, the main impact of the radiative forcing is an OHC increase at high latitudes, explained to some extent by a reduction in cloud cover and the subsequent increase of short-wave radiation at the surface. This OHC response is dominated by the effect of volcanism in the preindustrial era, and by the fast increase of GHGs during the last 150 yr. Likewise, salient impacts from internal climate variability are observed at regional scales. For instance, upper temperature in the equatorial Pacific is controlled by ENSO (El Nino Southern Oscillation) variability from interannual to multidecadal timescales. Also, both the Pacific Decadal Oscillation (PDO) and the Atlantic Multidecadal Oscillation (AMO) modulate intermittently the interdecadal OHC variability in the North Pacific and Mid Atlantic, respectively. The NAO, through its influence on North Atlantic surface heat fluxes and convection, also plays an important role on the OHC at multi, Ministerio de Ciencia e Innovación (MCINN), España, Ministerio de Medio Ambiente, Medio Rural y Marino (MARM), España, Centre national de la recherche scientifique CNRS-INSU, Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

Copyright 2011 by the American Geophysical Union. Supported in part by NSF grants ATM0902436 and ATM0902715, by NASA grant NNX09AF44G, by NOAA grants NA07OAR4310060 and NA10OAR4320137, and by the European Project Millennium. Supplementary materials can be accessed at http://www.ldeo.columbia.edu/similar to jsmerdon/2011_grl_supplement.html. LDEO contribution 7471., The spatial skill of four climate field reconstruction (CFR) methods is investigated using pseudoproxy experiments (PPEs) based on two millennial-length general circulation model simulations. Results indicate that presently available global and hemispheric CFRs for the Common Era likely suffer from spatial uncertainties not previously characterized. No individual method produced CFRs with universally superior spatial error statistics, making it difficult to advocate for one method over another. Northern Hemisphere means are shown to be insufficient for evaluating spatial skill, indicating that the spatial performance of future CFRs should be rigorously tested for dependence on proxy type and location, target data and employed methodologies. Observed model-dependent methodological performance also indicates that CFR methods must be tested across multiple models and conclusions from PPEs should be carefully evaluated against the spatial statistics of real-world climatic fields. Citation: Smerdon, J. E., A. Kaplan, E. Zorita, J. F. Gonzalez-Rouco, and M. N. Evans (2011), Spatial performance of four climate field reconstruction methods targeting the Common Era, Geophys. Res. Lett., 38, L11705, doi: 10.1029/2011GL047372., National Science Foundation (NSF), National Aeronautics and Space Administration (NASA), National Oceanic and Atmospheric Administration (NOAA), EE.UU., European Project Millennium, Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

© by Gebrüder Borntraeger 2010. Lund Regional-Scale Climate Modelling Workshop (2nd. 2009. Lund, Sweden). This work was funded by the Spanish Ministry of the Environment (project ESCENA, Ref. 20080050084265) and the Spanish Ministry of Science and Technology (project INVENTO -CGL2005-06966-C07-04/CLI). The authors also gratefully acknowledge the funding from the Euro-Mediterranean Institute of Water (IEA). Thanks to Christina SCHWARZ for the abstract translation., Three different Land Surface Models have been used in three high resolution climate simulations performed with the mesoscale model MM5 over the Iberian Peninsula. The main difference among them lies in the soil moisture treatment, which is dynamically modelled by only two of them (Noah and Pleim & Xiu models), while in the simplest model (Simple Five-Layers) it is fixed to climatological values. The simulated period covers 1958-2002, using the ERA40 reanalysis data as driving conditions. Focusing on near-surface air temperature, this work evaluates the skill of each simulation in reproducing mean values and temporal variability, by comparing the simulations with observed temperature series. When the simplest simulation was analyzed, the greatest discrepances were observed for the summer season, when both, the mean values and the temporal variability of the temperature series, were badly underestimated. These weaknesses are largely overcome in the other two simulations (performed by coupling a more advanced soil model to MM5), and there was greater concordance between the simulated and observed spatial patterns. The influence of a dynamic soil moisture parameterization and, therefore, a more realistic simulation of the latent and sensible heat fluxes between the land and the atmosphere, helps to explain these results., Drei verschiedene Landoberflächenmodelle wurden verwendet, um drei hochauflösende Klimasimulationen für die iberische Halbinsel mit Hilfe des mesoskaligen Modells MM5 durchzuführen. Der Unterschied der drei Modelle liegt hauptsächlich in der Behandlung der Bodenfeuchtigkeit, die in zwei der Modelle (Noah und Pleim & Xiu) dynamisch modelliert wird, während sie im einfachsten Modell (Simple Five-Layers) durch klimatologische Größen festgelegt ist. Die simulierte Zeitspanne reicht von 1958 bis 2002, wobei als Simulationsbedingungen die Reanalyse-Daten ERA40 dienen. Indem wir uns auf bodennahe Lufttemperaturen konzentrieren, wird in dieser Arbeit die Qualität jeder einzelnen Simulation, welche die beobachteten Jahreszyklen, die räumlichen Strukturen und die zeitlichen Veränderungen der Temperatur wiedergibt, durch den Vergleich mit instrumentellenMonatsmitteltemperaturserien ausgewertet. Die einfachste Simulation zeigt die größte Diskrepanz zu den Beobachtungen der Sommersaison, da die Temperaturmittel und die zeitlichen Veränderungen der Temperatur maßgeblich unterschätzt wurden. Diese Schwächen wurden in den beiden anderen Simulationen (in denen ein fortschrittlicheres Bodenmodell an MM5 gekoppelt wurde) zum größten Teil beseitigt und eine höhere übereinstimmung zwischen simulierten und beobachteten räumlichen Strukturen wurde erreicht. Der Einfluss einer dynamischen Bodenfeuchtigkeitsparametrisierung und dadurch eine realistischere Simulation des latenten Flusses und der Wärmestromdichte zwischen Boden und Atmosphäre begr ünden diese Ergebnisse weitgehend., Ministerio de Medio Ambiente (MMA), España, Ministerio de Ciencia y Tecnología (MCYT), España, Euro-Mediterranean Institute of Water (IEA), Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

© Author(s) 2011. This work is distributed under the Creative Commons Attribution 3.0 License. This work was funded by the Spanish Ministry of the Environment (project SALVA-SINOVAS, Ref. 200800050083542) and the Spanish Ministry of Science and Technology (project SPECMORE-CGL2008-06558-C02-02/CLI). The authors also gratefully acknowledge the funding from the Euro-Mediterranean Institute of Water (IEA). We acknowledge the E-OBS data set from the EU-FP6 project ENSEMBLES (http://ensembles-eu.metoffice.com) and the data providers in the ECA&D project (http://eca.knmi.nl). J. J. Gómez Navarro thanks the Spanish Ministry of Education for his Doctoral scholarship (AP2006-04100). We also thank Jürg Luterbacher for the interesting insights about uncertainties in proxy reconstructions, which improved the final version of this paper., A high-resolution (30 km) regional paleoclimate simulation of the last millennium over the Iberian Peninsula (IP) is presented. The simulation was performed with a climate version of the mesoscale model MM5 driven by the global model ECHO-G. Both models were driven by the same reconstructions of several external forcing factors. The high spatial resolution of the regional model allows climatologists to realistically simulate many aspects of the climate in the IP, as compared to an observational data set in the reference period 1961-1990. Although the spatial-averaged values developed by the regional model are tightly driven by the boundary conditions, it is capable to develop a different realisation of the past climate at regional scales, especially in the high-frequency domain and for precipitation. This has to be considered when comparing the results of climate simulations versus proxy reconstructions. A preliminary comparison of the simulation results with reconstructions of temperature and precipitation over the IP shows good agreement in the warming trends in the last century of the simulation, although there are large disagreements in key periods such as the precipitation anomalies in the Maunder Minimum., Ministerio de Medio Ambiente (MMA), Ministerio de Ciencia y Tecnología (MCYT), Euro-Mediterranean Institute of Water (IEA), Ministerio de Educación, Cultura y Deporte (MECD), ENSEMBLES-EU, Unión Europea. FP6, Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub