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XX Seminario Ibérico de Química Marina (SIQUIMAR 2020) - XX Iberian Seminar on Marine Chemistry, 1-3 July 2020, Barcelona.-- 2 pages.-- Samples were collected during the NextData Cruise on R/V Minerva I in June 2016, The present study aims at shedding light on the central Mediterranean Sea (MS) functioning in terms of water mass mixing and potential lithogenic sources by means of new geochemical tracers such as dissolved Nd isotopes (εNd) and Rare Earth Element (REE: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu) concentrations. Although proved to be valuable tracers of oceanographic processes, their measurements are basically lacking in the MS water column. We analyzed 9 stations around the Tyrrhenian, Ionian and Ligurian seas. Dissolved REE were measured with an Agilent 7500 ICP-MS and εNd using a Nu Plasma-III MC-ICP-MS at UB. The obtained REE do not display nutrient-like profiles, likely suggesting relatively young waters with limited accumulation of remineralized REE. Light REE (LREE: from La to Gd) present a non-conservative behavior, largely peaking at surface waters and rapidly decreasing with depth. The negative linear correlation of surface LREE enrichment with offshore distance indicates their release from lithogenic sediments of the Italian coast to the Tyrrhenian waters. In contrast to other regions, this process does not modify the εNd values. On the other side, distributions of dissolved heavy REE (HREE: Tb to Lu) and εNd exhibit a conservative behavior that can be explained by mixing of western- (MAW and WMDW) and eastern- (LIW and EMDW) originated waters. We test this hypothesis with an Optimum Multi-Parameter Analysis (OMPA) including HREE and εNd parameters. Even though the limited data set, consistent results of water mass fractions are obtained for the four main water masses although with some particularities. While LIW take on major importance when considering HREE in the model, EMDW fractions are preferentially detected with εNd. This latter finding implies a noticeable deep-water flux across the Sicily Strait into the Western Mediterranean that was not clearly evidenced before, The authors thank financial support from the OPERA Project (CTM2013-48639-C2-1-R), the CHIMERA Project (CTM2016-75411-R) and Generalitat de Catalunya (2017 SGR 315). This work has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant agreement No. 683237)

67 Sesión Científica de la Sociedad Geológica de España, 22-23 de noviembre de 2019, Peñarroya - Pueblonuevo, Córdoba.-- 4 pages, 2 figures, [EN] The sedimentary record of the contourite drift associated with the Djibouti Ville seamount (Alboran Sea, western Mediterranean) has been studied to reconstruct the source areas of the aeolian dust from Late Pleistocene to Holocene. Three end-member grain-size distributions address for different aeolian populations (coarse EM1, silty EM2 and fine EM3). For these particles, the most probable sour-ce areas are the Saharan sedimentary basins and deserts as well as the cratonic basins of the Sahara-Sahel corridor, whose prevalence in the core record changes by the MIS 5 to MIS 4 transition. Some punctual sediment inputs from the seamount have been recognized during sea-level low-stand but there is no evidence for fluvial supply in the drift deposits, [ES] Se ha realizado el estudio del registro sedimentario del drift con-tornítico asociado al monte submarino Villa de Djibouti (mar de Al-borán, Mediterráneo occidental) con el fin de reconstruir las áreas fuente de polvo eólico desde el Pleistoceno Superior al Holoceno. Se han podido diferenciar tres end-members (EM1 grueso, EM2 limoso y EM3 fino) que caracterizan la distribución granulométrica de las principales poblaciones de polvo eólico. Las áreas fuente más pro-bables de estas partículas son las cuencas sedimentarias y los de-siertos, así como las cuencas cratónicas del corredor Sahara-Sahel, cuya prevalencia en el registro sedimentario experimenta un cambio durante la transición de MIS 5 a MIS 4. Se han reconocido algunos aportes puntuales del monte coincidiendo con periodos de bajada del nivel del mar, pero no se han encontrado evidencias de aportes fluviales en los depósitos contorníticos, Este trabajo ha sido financiado por los proyectos MONTERA (CTM2009-14157-C02), SAGAS (CTM2005-08071-C03-02/MAR) y FAUCES (CTM2015-65461-C2-R) y por los fondos FEDER, With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)

34th International Association of Sedimentologists (IAS) Meeting of Sedimentology, Sedimentology to face societal challenges on risk, resources and record of the past, 10-13 September 2019, Rome.-- 1 page, The occurrence of extensive Plio-Quaternary contourite drifts in the Alboran region has recently been well documented, principally using geophysical methods. However, the sedimentological characteristics are not yet well documented, in spite of the fact that they provide a record of palaeoceanographic/climate changes. In this study, the sedimentary and geochemical characteristics of the contourite drifts formed by the Western Mediterranean Deep Water (WMDW) are examined in a core transect represented by three cores at 631 m, 712 m, and 914 m water depth. Three facies (1 to 3) are defined based on a combination of sedimentological and Zr/Al ratio. Facies 1 is the most dominant and consists of silty-clay, representing the finest-grained sediments; Facies 2 is composed of bioturbated clayey-silt with a remarkable Zr/Al peak, deposited during the Younger Dryas; Facies 3 consists of the coarsest sediments (sand), deposited during Heinrich event 2. The latter two facies present a remarkable Zr/Al peak. The mainly fine-grained contourites allow the Alboran contourite drifts to be classified as ¿muddy contourites¿. The vertical succession of these three facies permits the definition of two bi-gradational sequence types. Sequence A, represented by the vertical succession of facies 1, 2, 3, 2, 1, corresponds to the standard contourite sequence model, while Sequence B is composed of a vertical succession of facies 1, 2, 1, and corresponds to partial contourite sequences. Both sequences, A and B, are linked to shifts in the strength of the bottom currents, from weak to strong and then back to weak, corresponding to acceleration/deceleration periods. To decode the contourite facies successions in terms of bottom current speed, a comparison between two binary plots has been made: magnitude changes in mean sortable silt (meanss in µm) and changes in WMDW flow speed (in cm/s) versus four periods of acceleration of bottom currents (a: 23.4- 19 ka, b: 17.8-16.2 ka; c:15.0-12.5 ka; d: 9.8-8.0 ka). The regional Alboran palaeo-WMDW flow speed has been assessed using a similar record (meanss) from another contourite drift in the NW Mediterranean at 2391 m wd, close to the formation zone of the water mass. This comparison reveals that the Alboran contourite drifts were affected by low (~1.5-5.5 cm/s) and moderate flow speeds (~8-13 cm/s). These palaeo-speeds are in the same range as modern oceanographic data, indicating that the WMDW flow operated on the construction of those drifts in two hydrodynamic scenarios: Scenario 1 corresponded to low bottom current speeds (< 5.5 cm/s) for the period b; Scenario 2 was defined by higher bottom current speeds (up to ~12.8 cm/s), during the periods a, c, and d. This research represents a prime example of bottom current effect on the construction of contourite drifts and how to apply fine-grained, mainly muddy contourites in sedimentological and palaeoceanographic studies, despite the strong bioturbation. The core transect provides a regional perspective of bottom current flow, from close to its formation area along its pathway, which is governed by topographic restrictions (e.g., seamounts and submarine canyons), Contribution from Project FAUCES CTM2015-65461-C2-R (MINECO/FEDER)

XV Reunión Nacional Cuaternario, 1-5 July 2019, Bilbao.-- 4 pages, 4 figures, Se presenta un estudio sedimentológico y cronoestratigráfico de las contornitas del Mar de Alborán (Mediterráneo SO) en base al registro sedimentario de dos testigos de sedimento. En este estudio se incorporan marcadores físicos de corrientes de fondo (¿sortable silt mean grain size¿ meanss) y marcadores químicos de cambios ambientales (Si/Si+Al y Zr/Al ratios) con el objeto de decodificar las sucesiones de contorníticas en términos de variabilidad de velocidad de las corrientes de fondo en relación con cambios paleoambientales. Estos resultados son validados con la inclusión del registro del meanss de un testigo localizado en el Mediterráneo Nor-Occidental. Este transecto proporciona una perspectiva regional de los cambios de velocidades de la corriente profunda del Mediterráneo Occidental durante los últimos 24 ka B.P., This work was supported by the FAUCES Project (CTM2015-65461-C2-R; MINECO /FEDER)

Ponencia presentada en: XXXV Jornadas Científicas de la AME y el XIX Encuentro Hispano Luso de Meteorología celebrado en León, del 5 al 7 de marzo de 2018. Resumen de la introducción del volumen especial publicado en Noviembre de 2017 en la revista CLIVAR Exchanges (http://www.clivar.org/documents/exchanges-73) por parte del Comité CLIVAR-España, que muestra los avances en las diferentes líneas de investigación del clima en España, coordinadas por el comité, en los siguientes grandes apartados: paleoclima, reconstrucciones instrumentales, variabilidad climática y tendencias, observaciones oceánicas, regionalización atmosférica de clima presente y proyecciones futuras, y regionalización oceánica de clima presente y proyecciones futuras.

VI Simposio Internacional de Ciencias del Mar - VI International Symposium of Marine Sciences (ISMS 2018), 20- 22 June 2018, Vigo.-- 2 pages, The purpose of this study is to use dissolved Rare Earth Elements (dREE) and Nd isotopes (εNd) in sea water to better understand water-mass exchange and pathways in the Central Mediterranean (CM) Sea. We have analyzed 9 hydrographic stations around the Tyrrhenian Sea, Strait of Sicily and Ionian Sea (NextData2016 Cruise). Pre-concentrated and purified dREE were measured with an Agilent 7500 quadrupole ICP-MS while Nd isotopes (εNd) were determined using a Nu Plasma III Multicollector ICP-MS. In general, dREE abundances in the CM are similar to the western Mediterranean [1] but clearly lower than in the eastern basin [2] pointing to an eastward enrichment of Atlantic Waters, as for other trace metals. In addition, inflowing Atlantic Waters (εNd≈-10) become more radiogenic within its circulation (εNdup to -6). Light REE (LREE) present highest concentrations at surface waters, probably indicating lithogenic inputs. This is specially marked at the station closest to the continental margin with LREE enrichments relative to the other stations of 20-50%, with no significant εNd modification. Far from continental margins and below the surface, well-developed oceanic dREE patterns are found displaying negative cerium anomalies (Ce*=0.20-0.30) and enrichment of Heavy REE (HREE) demonstrating that water mass mixing governs the REE distribution below the permanent thermocline. Levantine Intermediate Waters (LIW) can be traced through a substantial HREE peak and distinctive radiogenic neodymium signature (εNd=-6.4). This is coherent with older waters enhanced with conservative HREE. Concerning εNd, the radiogenic imprint of LIW is in accordance with either the influence of partially dissolved Nile river particles [2] or the rock signature in the LIW formation zone [3]. Finally, both dHREE and εNd can be used to distinguish deep water masses: EMDW present εNd≈-6.7 and WMDW show εNdof -8.5, with the first being 13% more enriched in dHREE than the later, We authors thank financial support from the Italian Project of Strategic Interest NEXTDATA (http://www.nextdataproject.it) “A national system for recovery, storage, accessibility and dissemination of environmental and climatic data from mountain and marine areas” and from the OPERA Project (CTM2013-48639-C2-1-R) and Generalitat de Catalunya-Grups de Recerca Consolidats (2017 SGR 315). This work has been partially funded by the European Commission through an ERC Consolidator Grant to I. Cacho (TIMED; ID: 683237). Support from the Spanish Government for a post-doctoral fellowship to E. G-S. (FPDI-2013-15660) is also recognized. L.P. acknowledges support from the Ramón y Cajal program (MINECO, Spain). J.N.P-A. has been funded by a Postdoctoral fellowship Beatriu de Pinós (Generalitat de Catalunya, Marie Curie-COFUND actions)

XXXIII Jornadas de Paleontología de la Sociedad Española de Paleontología, Contribución de la Paleontología en los estudios Paleoceanográficos, 27-30 September 2017, Cadiz.-- 4 pages, Benthic foraminifera are a powerful proxy in paleoceanographic studies since they are sensitive to oceanographic parameters such as sea level, bottom-water ventilation and organic fluxes (Jorissen et al., 2007). Furthermore, water mass properties including temperature, salinity and nutrient content are recorded in their carbonate shells (Cacho et al., 2006). Consequently, the combination of micropaleontological and geochemical analyses on benthic foraminifera offers great potential to unravel past changes in ocean circulation and their relationship with climate oscillations. Here we present two examples of paleoceanographic reconstructions of Pleistocene to Holocene Mediterranean sediments using micropaleontological proxies: benthic foraminiferal assemblages, microhabitats, and oxygen index; and geochemical proxies: Mg/Ca-deep water temperatures (DWT), Cd/Ca, O and C stable isotopes

5th Past Global Changes (PAGES) Ocean Sciences Meeting, 9-13 May 2017, Zaragoza, The Subtropical Front (STF) separates warm and saltier subtropical waters from the cold, less saline and nutrient-rich subantarctic waters of the Southern Ocean. Determining its past north-south movements is crucial, for instance, to understand the role of such frontal systems on ocean productivity of the subantarctic region, as opposed to increased Fe availability. Three marine cores were recovered south of New Zealand, along a latitudinal transect crossing the modern STF. We have analysed long chain alkenones, as markers of coccolithophore productivity and past sea surface temperatures, n-alkanes and n-alcohols, as proxies for continental input and dust-derived iron and long chain diols as tracers of diatom productivity. Reconstructed SST changes show a 3-4°C temperature gradient during the Holocene between the core locations, while during the last glacial period no temperature gradient existed, with 8-9°C recorded at all three sites. This suggests a northward displacement of the STF during the cold glacial climate and the prevalence of subantarctic waters at the core sites, between 47 and 50.5°S. An increased productivity and continental input during the glacial and early deglaciation suggest that both Fe fertilization and equatorward migration of fronts likely drove the biological productivity of the region. The SST evolution will also be complemented with a temperature reconstruction based on the relative distribution of isoprenoid GDGTs, the TEXH86 index, which in this region, we believe may record deeper temperatures than coccolithophores

Special Issue on climate over the Iberian Peninsula: an overview of CLIVAR-Spain coordinated science.

The understanding of past multiannual-decadal climate variability in the Iberian Peninsula, and the long-term evolution of the main climate modes, can only be fully achieved if a large set of well resolved precipitation and temperature reconstructions are available. Such reconstructions can be obtained through a large array of proxies measured from different natural archives, like tree rings, lacustrine and marine sedimentary records, peatbog sequences and speleothems, among others. These climate reconstructions permit to characterize the main climate conditions and modes of climate variability at different geographical and time scales, and identify the stationary or non-stationary behaviour in the relationship of different climatic variables.

12th International Conference on Paleoceanography (ICP12), 29 August - 2 September 2016, Utrecht, It has been shown that the deep Eastern Equatorial Pacific (EEP) region was poorly ventilated during the Last Glacial Maximum (LGM) relative to Holocene values. In addition, surface productivity records from this region have indicated higher export productivity over this period. Together, these findings suggest a more efficient glacial biological pump, which indirectly supports the idea of increased carbon storage in the glacial deep ocean contributing to decreased LGM atmospheric CO2. However, proxies related to dissolved CO2 concentrations are needed in order to assess this proposition more directly. Here we present C. wuellerstorfi B/Ca ratios from ODP1240 measured by LA-IPCMS as a proxy for Δ[CO32-]insitu-sat (and therefore [CO32-]), along with δ13C measurements. Our results show lower [CO32-] and δ13C values during the LGM, which would be consistent with higher respired carbon levels in the deep EEP, driven by both reduced deep-water ventilation and higher export productivity. However, the ∆[CO32-]LGM-Holocene observed at ODP1240 is relatively small, suggesting that a “counteracting” mechanism, such as seafloor carbonate dissolution, also played a role. If so, this mechanism would have increased average ocean alkalinity, allowing even more atmospheric CO2 to be “sequestered” by the ocean. Similar deep-ventilation and ∆[CO32-]LGM-Holocene results have been shown by other records from the Pacific. Therefore, the deep Pacific Ocean very likely sequestered a significant amount of atmospheric CO2 during the LGM, specifically due to a more efficient biological carbon pump, but also to an increase in average ocean alkalinity

17 pages, 6 figures, 1 table, supporting information https://dx.doi.org/10.1002/2015PA002883, data will be available at the Scientific Earth Drilling Information Service (http://sedis.iodp.org), Pangaea website (http://www.pangaea.de), and NOAA Paleoclimatology (https://www.ncdc.noaa.gov/data-access/paleoclimatology-data), Here we present a new set of high-resolution early Pleistocene records from the eastern equatorial Pacific (EEP). Sediment composition from Ocean Drilling Program Sites 1240 and 1238 is used to reconstruct past changes in the atmosphere-ocean system. Particularly remarkable is the presence of laminated diatom oozes (LDOs) during glacial periods between 1.85 and 2.25 Ma coinciding with high fluxes of opal and total organic carbon. Relatively low lithic particles (coarse and poorly sorted) and iron fluxes during these glacial periods indicate that the increased diatom productivity did not result from dust-stimulated fertilization events. We argue that glacial fertilization occurred through the advection of nutrient-rich waters from the Southern Ocean. In contrast, glacial periods after 1.85 Ma are characterized by enhanced dust transport of finer lithic particles acting as a new source of nutrients in the EEP. The benthic ecosystem shows dissimilar responses to the high productivity recorded during glacial periods before and after 1.85 Ma, which suggests that the transport processes delivering organic matter to the deep sea also changed. Different depositional processes are interpreted to be the result of two distinct glacial positions of the Intertropical Convergence Zone (ITCZ). Before 1.85 Ma, the ITCZ was above the equator, with weak local winds and enhanced wet deposition of dust. After 1.85 Ma, the glacial ITCZ was displaced northward, thus bringing stronger winds and stimulating upwelling in the EEP. The glacial period at 1.65 Ma with the most intense LDOs supports a rapid southward migration of the ITCZ comparable to those glacial periods before 1.85 Ma, This work has been funded by Ministerio de Ciencia e Innovación Project GRACCIE (CONSOLIDER-INGENIO CSD 2007-00067) and ACDC project (CTM 2009-08849). The ODP is sponsored by the U.S. National Science Foundation (NSF) and participating countries under management of Joint Oceanographic Institutions. Grup de Recerca Consolidat en Geociències Marines is funded by Generalitat de Catalunya autonomous government through its excellence research groups program (reference 2014 SGR 1068). The paleostudy program (European Science Foundation) provided the funding necessary to AM to carry out the XRF core scanner analysis in the University of Bremen

12th International Conference on Paleoceanography (ICP12), 29 August - 2 September 2016, Utrecht, Research on the physical and biological processes controlling the transitions from glacial to interglacial periods has mostly focused on the most recent Termination (TI). However, studying previous deglaciations should provide further insights into the mechanisms involved during these transitions. In this study, we focus on the penultimate deglaciation in the Eastern Equatorial Pacific (EEP), a strategic location under the influence of upwelled nutrient-rich waters and a tight link with the Southern Ocean (SO) through the advection of intermediate waters. We present a multiproxy record of surface ocean productivity, dust inputs and thermocline conditions across TII(110¿ 150 kyr BP). These new records will allow us to assess responses of the phytoplankton community to changes in the surface water chemistry. Our records suggest enhanced dust input and high primary productivity during the end of the penultimate glacial maximum. A prominent peak in diatom production at the middle of the transition points to the arrival of Si-rich waters to the EEP, which would have promoted the growth of these organisms. The coincidence of this peak with a minimum in the ¿13C signal of deep thermocline dwelling foraminifera from the same core, used as a proxy for the influence of subantarctic sourced waters, suggests that a silicic acid leakage from the SO through intermediate waters occurred during the TII, similar to what was reported in this area for TI (Calvo et al., 2011, PNAS)

Aquatic Sciences Meeting, Aquatic Sciences: Global And Regional Perspectives - North Meets South, 22-27 February 2015, Granada, Spain, Last deglaciation in the Eastern Equatorial Pacific Ocean involved an intense reorganization of the upwelling system with the consequent changes in the nutrient budget, phytoplankton ecology and carbon fluxes towards the deep ocean. A multi-proxy study from ODP site 1240 provides a very complete insight on the time evolution of these changes. Sea surface temperature reconstructions based in both G. ruber-Mg/Ca ratios and alkenones show a strong seasonal gradient during this period induced by precession-driven changes in insolation. Thermocline records based in N. dutertrei chemistry support an enhancement of the upwelling system during this period. The combined study of molecular biomarkers indicate a significant change in the main phytoplankton producers along this period which is associated to a change in water fertilization processes, first by atmospheric iron deposition followed by the arrival of nutrient enriched undercurrent waters. The arrival of Antarctic source waters enriched in silicic acid during this period is further supported by the study of Nd isotopes

Aquatic Sciences Meeting, Aquatic Sciences: Global And Regional Perspectives - North Meets South, 22-27 February 2015, Granada, Spain, EEP (ODP 1240) provides a unique opportunity to reconstruct coupled changes in the atmosphere-ocean systems through the analysis of lithic and biogenic components, from 1.6 to 2.2 Ma. The methodology combines δ18O in benthic foraminifera, Uvigerina spp. abundance, Sibio, TOC, lithic fraction and Fe-XRF composition. Throughout the studied period, can be clearly distinguished the glacial periods prior to 1.85 Ma, dominated by low Fe and sparse lithogenic grains, poorly sorted and coarser, which could reflect the dominance of stronger local trade winds with a northward ITCZ position. Surprisingly, high TOC and Si values also occurred during these low-Fe periods, albeit Uvigerina spp. did not benefit from them, indicating that this diatom productivity was not dust stimulated. These intervals correspond to Laminated Diatom Oozes (LDO), suggesting an enhanced upwelling system of rich-silica waters probably from the Southern Ocean and would have promoted a very efficient OM transport towards the deep sea, changing drastically the ecosystem. Moreover, glacial periods after 1.85 Ma show a Fe-dust stimulated productivity with a reduced C flux towards the deep ocean that stimulated the Uvigerina spp. development

The eastern equatorial Pacific (EEP) is one of the key areas for studying oceanic processes that control atmospheric CO2 concentrations. Southern-sourced water masses (SOIW) are thought to stimulate the biological pump in the EEP and hence contributed to the CO2 drawdown during glacial times. Orbital forcing in combination with local feedback mechanisms are assumed to be the main driver for this water mass advection. Newest studies, however, question the capability of SOIW to stimulate primary productivity during Marine Isotope Stage 2 (MIS2), as nutrients are rather utilized in the Southern Ocean. Instead, nutrient-rich Glacial North Pacific Intermediate Waters (GNPIW) seem to be a major component of water masses upwelled in the EEP to enhance productivity in the EEP during MIS2. We present changes in biological productivity in the EEP over the last 190 ka derived from surface-dwelling planktic foraminifera Globigerinoides ruber and deep-dwelling planktic foraminifera Globorotaloides hexagonus (ODP Site 1240). The δ13C gradient between surface and sub-thermocline (Δδ13Crub-hex) has been used to assess export production in that area. We compare this with variations in the nutrient gradient (Δδ13Chex-SOIW) between sub-thermocline equatorial waters (~350 m) and SOIW. The Δδ13Chex-SOIW variability is dominated by 100 kyr and 23 kyr cycles. This implies a strong response to changes in orbital precession and internal climate forcing related to major changes in ice volume. At times of low precession the difference between the nutrient concentrations of EEP waters and nutrients delivered via SOIW differ substantially, thus indicating that SOIW is not providing sufficient nutrients to stimulate productivity in the EEP. This scenario is most prominent during MIS2 and MIS6. Following the interpretation by Max et al. (submitted) we speculate that similar to MIS2, nutrients were trapped in the Southern Ocean also during MIS6 leaving northward-advected SOIW rather nutrient-depleted. Similar to MIS 2, we assume a greater contribution and hence, influence of nutrients from GNPIW on the productivity of the EEP during MIS6. A switch from GNPIW to SOIW influence of water masses upwelled in the EEP is recorded during glacial terminations.

2014 American Geophysical Union Fall Meeting, 15-19 december 2014, San Francisco, It has been hypothesised that a poorly ventilated deep Pacific Ocean would have contributed significantly to reduce glacial atmospheric CO2. Although radiocarbon evidence for a deglacial rise in deep Pacific ventilation so far remains conflicting, this may stem in part from surface reservoir age uncertainties and their effect on inferred deep ocean ventilation ages. Here we use chronostratigraphic calendar age constraints to estimate surface reservoir age variability, and therefore deep ventilation ages, in the Eastern Equatorial Pacific over the last 25 kyr. Both the shallow- and deep ventilation records show a deglacial decrease in glacial radiocarbon depletion, consistent with other South Pacific and Southern Ocean ventilation reconstructions where surface reservoir ages have been assessed. We propose that this basin-wide agreement can be explained by ocean interior transport pathways similar to the modern, implying significantly reduced air-sea gas exchange in the southern high latitudes during the last glacial period

[EN] The concentration of several trace elements (Mg, Ba, Sr,Al, Si and P) has been analyzed in two speleothems, corresponding to MIS-5 and MIS-1 according to U/Th dating, and one recent deposit, experimentally recorded.All them belong to La Paz cave in Ortigosa de Cameros (La Rioja). The analyzed trace element content displays a seasonality that agrees with the speleothem lamination.Trace element concentration is higher in the dark laminae, formed during the fall-winter season. This content is linked to the flushing into the cave of organic matter from soil activity, in fall, when precipitation resumes. Mg/Ca and Sr/Ca evolutions point to a decrease of humidity during MIS-5 with respect to MIS-1, whereas at present aridity increases, probably in relation to an enlarging of the seasonal contrast., [ES] Se estudia la concentración de varios elementos traza (Mg, Ba, Sr,Al, Si y P) en dos espeleotemas, datados por U/Th como MIS-5 y MIS-1, y en un depósito actual, de origen experimental, todos ellos de la cueva de La Paz en Ortigosa de Cameros (La Rioja). Los elementos analizados muestran una estacionalidad acorde con la laminación de los depósitos. La concentración de trazas es mayor en las láminas oscuras, correspondientes a otoño-invierno, asociada a la materia orgánica procedente de la actividad edáfica, que es introducida por las precipitaciones de otoño, tras la sequía estival. Las evoluciones de Mg/Ca y Sr/Ca indican una disminución de la humedad durante el MIS-5 respecto al MIS-1, mientras que en la actualidad hay un aumento de la aridez. Estas variaciones podrían estar influenciadas por modificaciones del contraste estacional., Este trabajo ha sido financiado por el proyecto CGL2009-10455/BTE (Ministerio de Ciencia e Innovación y Fondos Europeos). Agradecemos la colaboración del Ayuntamiento de Ortigosa de Cameros y de Mª Ángeles, Sara y Juan. Agradecemos también las sugerencias de la Dra. Ana Alonso Zarza en la revisión del manuscrito.

Early and Mid-Pleistocene climate, ocean hydrography and ice sheet dynamics have been reconstructed using a high-resolution data set (planktonic and benthic delta O-18 time series, faunal-based sea surface temperature (SST) reconstructions and ice-rafted debris (IRD)) record from a high-deposition-rate sedimentary succession recovered at the Gardar Drift formation in the subpolar North Atlantic (Integrated Ocean Drilling Program Leg 306, Site U1314). Our sedimentary record spans from late in Marine Isotope Stage (MIS) 31 to MIS 19 (1069-779 ka). Different trends of the benthic and planktonic oxygen isotopes, SST and IRD records before and after MIS 25 (similar to 940 ka) evidence the large increase in Northern Hemisphere ice-volume, linked to the cyclicity change from the 41-kyr to the 100-kyr that occurred during the Mid-Pleistocene Transition (MPT). Beside longer glacial-interglacial (G-IG) variability, millennial-scale fluctuations were a pervasive feature across our study. Negative excursions in the benthic delta O-18 time series observed at the times of IRD events may be related to glacio-eustatic changes due to ice sheets retreats and/or to changes in deep hydrography. Time series analysis on surface water proxies (IRD, SST and planktonic delta O-18) of the interval between MIS 31 to MIS 26 shows that the timing of these millennial-scale climate changes are related to half-precessional (10 kyr) components of the insolation forcing, which are interpreted as cross-equatorial heat transport toward high latitudes during both equinox insolation maxima at the equator.

16 páginas, 2 figuras, 1 tabla.-- Capítulo 1 del Informe de evaluación del Cambio Climático Regional.

Climate change is nowadays a reality and one of the most important challenges that humanity has to face this century, because of the threat that it represents, among others, for the economy, health, food and safety. There are increasingly more scientific evidences that we are at a critical moment, although we can still tackle the negative consequences of climate change if we take decisive actions at a global level. One of the key actions needed to meet this challenge is to gain as detailed an understanding as possible of how the climate is changing, what the climate will be like in the next hundred years and how these changes are going to affect us. This is where the scientific community plays a central role, since the formulation of policies for mitigating and adapting to climate change depends on accurate scientific knowledge. The CLIVAR-Spain Committee and Thematic Network, whose activities I have been supporting since it was created in 2004, has built itself up over the course of the last five years as a network that seeks to promote climate research and advance scientific knowledge of climate change in Spain. Its first report, published in 2006, entitled “The state of the art of the Spanish contribution to the Climate Variability and Predictability (CLIVAR) study”, enabled us to gain a better understanding of the state of climate research in Spain. Now this second report comes at a key moment, just after the Copenhagen Summit in which, once again, the urgent need to take steps to face climate change and the importance of scientific knowledge as a guide to this process have been made clear. Structured in five sections, this report contains highly relevant information about climate variability and climate changes (both past and recent), future climate projections and projected variations in the frequency and intensity of extreme events in the Iberian Peninsula, which, as the IPCC indicates in its recent Fourth Assessment Report, is a region that is particularly vulnerable to climate changes. Undoubtedly, this information will be highly useful for planning actions in areas liable to be affected by climate change. As I did at the time of the presentation of the First Report, I would like once again to express my support to the CLIVAR-Spain committee and to encourage it to continue to publish periodic assessment reports. I also wish to extend my support to the Spanish scientists who comprise the CLIVAR-Spain Thematic Network, so that they continue to endeavour in their research on climate and climate change in Spain. Without a doubt, both efforts will help boost the research activities of other national and international initiatives in the field of climate variability and climate change and will promote greater participation of national research efforts and researchers at the international level.

Sumario: Capítulo 0: Resumen Ejecutivo e Introducción. Capítulo 1: Revisión de las reconstrucciones paleoclimáticas en la Península Ibérica desde el último periodo glacial. Capítulo 2: Tendencias atmosféricas en la Península Ibérica durante el período instrumental en el contexto de la variabilidad natural. Capítulo 3: Variabilidad oceánica y de nivel de mar en el entorno de la Península Ibérica. Capítulo 4: Teleconexiones climáticas en el entorno de la Península Ibérica. Predictabilidad y cambios esperados. Capítulo 5: Proyecciones regionales de clima sobre la Península Ibérica: modelización de escenarios de cambio climático. ANEXO I: La Pequeña Edad del Hielo (LIA, Little Ice Age) y el Periodo Cálido Medieval (MWP, Medieval Warm Period). ANEXO II: La Oscilación del Atlántico Norte (NAO). ANEXO III: Escenarios de emisiones. El informe "Clima en España: Pasado, presente y futuro" elaborado por los investigadores de la red temática CLIVAR-España se presentó el pasado 12 de Abril de 2010 en Madrid, en un acto oficiado por la secretaria de Estado de Cambio Climático, Teresa Ribera. Este informe sintetiza y evalúa la información existente sobre los aspectos físicos del cambio climático reciente observado en la Península Ibérica e intenta mejorar nuestra comprensión de los cambios climáticos que afectan y han afectado a la PI, para poder anticipar mejor los impactos de futuros cambios en el clima a distintas escalas temporales.

Este informe de la Red Temática CLIVAR-España sintetiza y evalúa la información existente sobre los aspectos físicos del cambio climático reciente observado en la Península Ibérica (PI) e intenta mejorar nuestra comprensión de los cambios climáticos que afectan y han afectado a la PI, para poder anticipar mejor los impactos de futuros cambios en el clima a distintas escalas temporales.

This paper documents the migration of the Polar Front (PF) over the Iberian margin during some of the cold climatic extremes of the last 45 ka. It is based on a compilation of robust and coherent paleohydrological proxies obtained from eleven cores distributed between 36 and 42 degrees N. Planktonic delta O-18 (Globigerina bulloides), ice-rafted detritus concentrations, and the relative abundance of the polar foraminifera Neogloboquadrina pachyderma sinistral were used to track the PF position. These three data sets, compared from core to core, show a consistent evolution of the sea surface paleohydrology along the Iberian margin over the last 45 ka. We focused on five time slices representative of cold periods under distinct paleoenvironmental forcings: the 8.2 ka event and the Younger Dryas (two recent cold events occurring within high values of summer insolation), Heinrich events 1 and 4 (reflecting major episodes of massive iceberg discharges into the North Atlantic), and the Last Glacial Maximum (typifying the highest ice volume accumulated in the Northern Hemisphere). For each event, we generated schematic maps mirroring past sea surface hydrological conditions. The maps revealed that the Polar Front presence along the Iberian margin was restricted to Heinrich events. The sea surface conditions during the Last Glacial Maximum were close to those at present day, except for the northern sites which briefly experienced subarctic conditions.

13 pages, 4 figures, 1 table, The advent of new microanalytical techniques such as electron microprobe mapping (EMP) and laser ablation microsamplers coupled to mass spectrometers (LA-ICP-MS) provides a new array of possibilities to explore in great detail the trace elements distribution in foraminiferal carbonates. Here we apply these techniques to characterize diagenetic phases present in foraminiferal shells from Ocean Drilling Program Site 1240 in the Panama Basin, a region characterized by the presence of manganese-rich minerals in the sediments. The combined application of these techniques allows us to characterize the elemental and spatial distribution on the surface and across the foraminiferal shells. Results illustrate the presence of at least two different Mn-rich contaminant phases in the foraminiferal carbonates: Mn-rich carbonates and ferromanganese oxides. Elemental maps also highlight the relevance of the foraminifera shell texture and porosity in the distribution and formation of these contaminant phases. In the case of Neogloboquadrina dutertrei, Mn phases form a continuous thin layer in the inner part of the chambers, whereas for Globigerinoides ruber, Mn phases have a rather patchy distribution and are usually found within the pores. Significant high magnesium concentrations are always associated with these Mn-rich phases. These new findings support the need of removing these Mn-rich contaminant phases in order to measure accurately the Mg/Ca ratios in the foraminifera shell and therefore obtain reliable Mg/Ca paleotemperature reconstructions, Funding for this research was also provided by the Natural Environment Research Council through UK-ODP. This work was supported in part by the Spanish Ministry of Science and Innovation through project ROMIAT (CTM2006-01957/MAR). E.C. and I.C. also acknowledge support through a Ramón y Cajal contract from the Spanish Ministry of Education and Science

The eastern Mediterranean sapropels are amongst the most intensively investigated phenomena in the palaeoceanographic record , but relatively little has been written regarding the origin of the equivalent of the sapropels in the western Mediterranean, the Organic Rich Layers (ORL's). ORL's are recognised as sediment layers containing enhanced Total Organic Carbon that extend throughout the deep basins of the Western Mediterranean, and are associated with enhanced total barium concentration and a reduced diversity (dysoxic but not anoxic) benthic foraminiferal assemblage. Consequently, it has been suggested that ORL's represent periods of enhanced productivity coupled with reduced deep ventilation, presumably related to increased continental runoff, in close analogy to the sapropels. We demonstrate that despite their superficial similarity, the timing of the deposition of the most recent ORL in the Alboran Sea is different to that of the approximately coincident sapropel, indicating that there are important differences between their modes of formation. We go on to demonstrate, through physical arguments, that a likely explanation for the origin of the Alboran ORLs lies in the response of the Western Mediterranean basin to a strong reduction in surface water density and a shoaling of the interface between intermediate and deep water during the deglacial period. This moves the emphasis for forcing deep convection collapse in the western basins away from atmospheric forcing and towards changes in the residence time of water in the Mediterranean Sea (i.e. oceanic forcing). Furthermore, we provide evidence that deep convection had already slowed by the time of Heinrich Event 1, and explore this event as a potential agent for preconditioning deep convection collapse. Important differences between Heinrich-like and deglacial-like influences are highlighted, giving insight into the response of the western Mediterranean system to external forcing.

16 pages, 2 tables, 6 figures., The detailed analysis of the International Marine Past Global Changes Study core MD99-2343 recovered from a sediment drift at 2391 m water depth north of the island of Minorca illustrates the effects of climate variability on thermohaline circulation in the western Mediterranean during the last 12 kyr. Geochemical ratios associated with terrigenous input resulted in the identification of four phases representing different climatic and deepwater overturning conditions in the Western Mediterranean Basin during the Holocene. Superimposed on the general trend, eight centennial- to millennial-scale abrupt events appear consistently in both grain size and geochemical records, which supports the occurrence of episodes of deepwater overturning reinforcement in the Western Mediterranean Basin. The observed periodicity for these abrupt events is in agreement with the previously defined Holocene cooling events of the North Atlantic region, thus supporting a strong Atlantic Mediterranean climatic link at high-frequency time intervais during the last 12 kyr. The rapid response of the Mediterranean thermohaline circulation to climate change in the North Atlantic stresses the importance of atmospheric teleconnections in transferring c1imate variability from high latitudes to midlatitudes., Funding by the European Commission Fifth and Sixth Framework Programmes to projects ADIOS (EVK3-2000- 00035), PROMESS 1 (EVR1-CT-2002-40024), EUROSTRATAFORM (EVK3-2002-00079), and HERMES (GOCE-CT-2005-5 11234-1) supported the research effort behind this paper. The Spanish-funded BTE2002-04670 and REN2003-08642-C02-02 projects are equally acknowledged. We are especially grateful to the Marion Dufresne and the IMAGES programirie that enabled the collection of cores MD99-2343 and MD95-2043. GRC Geociències Marines is recognized within the Generalitat de Catalunya excellence research groups program (reference 2005SGR 00152). We thank M. Guart (Departament d’Estratigrafia, Paleontologia i Geociències Marines, University of Barcelona) and E. Seguí (Serveis Cientifico-Técnics, University of Barcelona) for their help with the laboratory work and G. Lastras and D. Amblas for their help with the artwork. The Editor G. Dickens, J. B. Stuut, and two anonymous reviewers are greatly acknowledged for their positive comments on an earlier version of the manuscript. COMER Foundation and 13P postdoctoral programme (CSIC) are also acknowledged for their support to I. Cacho and A. Moreno, respectively. J. Frigola benefited from a fellowship of the University of Barcelona.

10 pages, 5 figures, [EN] In the present paper we make a general description of the application of molecular biomarkers in the reconstruction of past sea surface temperatures (SST). This methodology has been developed over the last decade, and its use in paleoceanographic studies becomes increasingly extended, evidencing its great value as paleoclimatic proxy. SST are calculated using the unsaturation index Uk37, which measures the relative occurrence of the C37 di-and tri-unsaturated linear ketones (alkenones). This paper reviews the historical evolution of this method, focusing on the analytical methodology available for the determination of the Uk37 index, [ES] En este trabajo describimos de forma general la aplicación del análisis de biomarcadores moleculares en la reconstrucción de las temperaturas superficiales marinas (SST) de los océanos del pasado. Esta metodología se ha desarrollado durante la última década y su uso está cada vez más extendido en estudios paleoceanográficos, demostrando su gran valor como indicador paleoclimático. El cálculo de las SST se realiza a partir del índice de insaturación Uk 37, que viene dado por la concentración relativa de dos compuestos moleculares de los sedimentos marinos, cetonas lineales de 37 átomos de carbono di y tri-insaturadas (alquenonas). Este trabajo pretende revisar de manera práctica el desarrollo de este método desde sus inicios, haciendo hincapié en la metodología analítica para la determinación del índice Uk 37