How much warmer is the Mediterranean becoming? : thirty-five years of satellite observations

Global warming particularly affects the oceans and seas. In the Mediterranean Sea, in situ oceanographic and meteorological records, together with the most recent satellite observations, show an estimated warming of between 0.6 °C and 1 °C over the last three decades. In this article we present the results of an analysis of a 35-year series of monthly thermal images in the western basins of the Mediterranean. The data indicate an intensification in the summer season: with the summers becoming longer and more intense and the months of June and July recording the highest rates of warming, with increases of 0.6 °C/decade

Recent warming in the Balearic Sea and Spanish Mediterranean coast. Towards an earlier and longer summer

This paper analyses recent changes in the temperature of the Balearic Sea and surrounding coastal areas. Monthly temperature data from several weather stations located around the Balearic basin have been used to obtain land temperatures during the period 1960-2010, and monthly thermal satellite images from the Physical Oceanography Distributed Active Archive Center (PO.DAAC) covering the period 1985-2009 have been processed to obtain sea surface temperatures (SSTs) in the Balearic Sea. A rise in temperature has been observed since 1980 and increasingly in the last 25 years, with an average warming trend of 0.039 ºC/year on land for the period 1960-2010 and 0.026 ºC/year in SSTs for 1985-2009. The seasonal analysis showed that, in the last 25 years, higher trends were registered during the transition from spring to summer, with the highest warming rates in June (0.12 ºC/year on land and 0.08 ºC/year in SSTs). Results show a recent tendency towards earlier and longer summers both on land and sea

SST Comparison of AVHRR and MODIS Time Series in the Western Mediterranean Sea

La temperatura de la superficie del mar (SST) es un parámetro clave para comprender los procesos atmosféricos y oceánicos. Desde finales de la década de 1980, las imágenes de satélite infrarrojas se han utilizado para complementar los registros in situ para estudiar la variabilidad temporal y espacial de la SST. El radiómetro avanzado de muy alta resolución (AVHRR) del satélite de la Administración Nacional Oceánica y Atmosférica (NOAA) fue el primer sensor utilizado con éxito para calcular la SST después del desarrollo y validación del algoritmo de corrección atmosférica conocido como 'ventana dividida'. Más recientemente, el espectrorradiómetro de imágenes de resolución MODERADA (MODIS) a bordo de los satélites Terra y Aqua de la Administración Nacional de Aeronáutica y del Espacio (NASA), lanzados en 1999 y 2002, respectivamente, también proporciona productos SST que se pueden combinar con la serie AVHRR para completar el análisis de series de tiempo. Este artículo presenta una comparación de los datos mensuales de TSM derivados de ambos sensores, AVHRR y MODIS, en una serie de diez años (2000-2009) en las cuencas del Mediterráneo occidental. Los resultados mostraron una alta correlación (R2 = 0,99) entre los sensores cuando se compararon los valores promediados a escala regional. La SST obtenida de AVHRR fue ligeramente superior (+0,18 ° C ± 0,2 ° C, en promedio) que la SST de MODIS. Las series fueron más similares durante el invierno y la primavera (+0,09 ° C ± 0,1 ° C de enero a mayo) con una mayor diferencia de junio a diciembre (+0,24 ° C ± 0,2 ° C). El análisis comparativo mostró que los dos sensores se pueden utilizar en conjunto para estimar tendencias a largo plazo a escala regional. Sea Surface Temperature (SST) is a key parameter for understanding atmospheric and oceanic processes. Since the late 1980s, infrared satellite images have been used to complement in situ records for studying the temporal and spatial variability of SST. The Advanced Very High Resolution Radiometer (AVHRR) of the National Oceanic and Atmospheric Administration (NOAA)'s satellite was the first sensor successfully used to compute SST following the development and validation of the atmospheric correction algorithm known as 'split-window'. More recently, the MODerate-resolution Imaging Spectroradiometer (MODIS) on board the National Aeronautics and Space Administration (NASA)'s Terra and Aqua satellites, launched in 1999 and 2002, respectively, also provides SST products which can be combined with AVHRR series to complete the analysis of time series. This paper presents a comparison of the monthly SST data derived from both sensors, AVHRR and MODIS, in a series of ten years (2000-2009) in the Western Mediterranean basins. The results showed a high correlation (R2 = 0.99) between the sensors when averaged values at the regional scale were compared. SST obtained from AVHRR were slightly higher (+0.18 °C ± 0.2 °C, on average) than SST from MODIS. The series were most similar during winter and spring (+0.09 °C ± 0.1 °C for January to May) with a greater difference from June to December (+0.24 °C ± 0.2 °C). The comparative analysis showed that the two sensors can be used jointly to estimate long-term trends at the regional scale

Criterios de selección y caracterización de episodios de lluvia. Aplicación a la Confederación Hidrográfica del Júcar (1989-2003)

El análisis espacio-temporal de la lluvia precisa de la identificación de episodios, en función del objetivo de la investigación y la escala de trabajo. En esta comunicación se proponen criterios de selección de episodios, con objetivos hidrológicos, y se aplican al territorio de la Confederación Hidrográfica del Júcar, en base a los datos diarios de 15 años (1989-2003), proporcionados por el Sistema Automático de Información Hidrológica. Se seleccionan 363 episodios y se caracterizan en base a indicadores de total, duración, intensidad e irregularidad, calculados en once unidades territoriales. El análisis de estos indicadores evidencia una dicotomía litoral-interior. El ámbito litoral (exceptuando Alicante) registra el mayor número de episodios, fundamentalmente en invierno, con un aporte más importante y mayor irregularidad. Por el contrario, en el ámbito de interior los episodios son de menor intensidad y mayor presencia en verano. El efecto orográfico es importante, no sólo por la altitud, sino por la orientación de las cadenas montañosas.Before analysing the variability of rainfall in space and time it is necessary to select rainfall events in relation to the objectives and scale of the study. This paper proposes criteria for selecting rainfall events, with hydrological objectives. These criteria are then applied to the territory of the River Jucar Water Authority and the daily data covering a 15 year period (1989-2003) recorded by the Automatic Hydrological Information System (SAIH). 363 events are chosen and characterised by indicators of total rainfall, duration, intensity and irregularity calculated over 11 regional units. The analysis of these indicators shows a littoral-interior dichotomy. The largest number of events were recorded near the coast (except in one region), mostly in winter, with greatest volumes and higher irregularity. In the interior the events were less intense and more frequent in summer. The orographic effect is important, not just in relation to altitude but also in relation to the orientation of the mountain ranges

Asterocheres hirsutus, a new species of parasitic copepod (Siphonostomatoida : Asterocheridae) associated with an Antarctic hexactinellid sponge

The asterocherid siphonostomatoid copepod Asterocheres hirsutus, a new species, is described from a hexactinellid sponge of the genus Rossella Carter collected during the Polastern cruise ANT XVII/3, off South Shetland Islands. The distinctive features of this new species are: a female with 21-segmented and a male with 17-segmented antennules, praecoxal endite of maxillule more than four times longer than palp and the ornamentation of the posterior surface of legs 1–4. A detailed description of both sexes is presented

An ASIC channel for acid chemotransduction

Producción CientíficaSpontaneous breathing requires feedback controls in which detection of blood gas and pH are critical. While O2 detection is performed by pheripheral chemoreceptors, CO2/pH-sensitive chemoreceptors are in the carotid bodies (CBs), but major sites are also within the brain (the central chemoreceptors [CCR]). CO2/pH signals are related to the acid-base status of the blood and reflect the adequacy of breathing to metabolism. Small changes in CO2/pH can affect breathing, so that a rise in Pco2 as small as 1 mm Hg produces an evident change in ventilation.1 Such a high CO2 sensitivity relies in the inherent properties of CO2/pH-sensing molecules present both in CB and CCR cells, as shown in several recent studies on CO2/pH sensing ion channels and receptors.2,3 Functional properties of most proteins can be regulated by changes in pH, as this would only require 1 or a few titratable residues of the molecule, whose protonation can lead to conformation changes that translate into changes in activity. However, to define whether those molecules have a relevant role in CO2/pH chemoreception, some more criteria should be met, including their range of pH sensitivity, their location in chemoreceptor cells, and their functional contribution to the integrated chemoreceptor response. In this regard, the molecular characterization of pH-sensitive channels and transporters has progressed considerably within the last years, but conclusive evidences of their contribution to acid chemotransduction are not so well established for many of them. The main reason for this delay is the fact that the identity of the primary sensory cells constituting CCRs and of their neuronal networks remains elusive. In vitro, neurons from many brain locations are excited or inhibited by CO2/pH changes, but it has been difficult to link this neuronal chemosensitivity to chemoreception in vivo. Moreover, in addition to chemosensitive neurons, CCRs sites may also contain neurons with other integrative functions that are not clearly distinct from chemosensitive ones in their morphological or functional properties, making their experimental study difficult.Ministerio de Sanidad, Consumo y Bienestar Social - Instituto de Salud Carlos III (grants R006/009 and PI041044)Ministerio de Ciencia, Innovación y Universidades (grant BFU2004-05551)Junta de Castilla y León (grant VA011C05

Are Kv channels the essence of O2 sensing?

Producción CientíficaThis report represents a relevant contribution to the study of oxygen sensing for two main reasons. First, it shows an approach adequate for identification of a putative O2-sensitive K+ channel, by moving from the modulation by hypoxia of a recombinant channel back to its physiological context, the role of this channel in the response to low Po2 of the native cells. Second, it demonstrates that hypoxic inhibition of the recombinant Kv3.1 channels is retained in excised membrane patches, pointing to a membrane-delimited mechanism as the origin of hypoxic responses. The importance of this latter finding deserves additional comment

Identification of Mediterranean rainfall events for hydrological analysis. Criteria and characterization

Since Mediterranean environments are characterized by the irregularity of their climate and hydrological processes where, for instance, twice or even three times the average annual rainfall can be registered in a single torrential rainfall event, hydrological studies are increasing focussing on the analysis of actual rainfall events. Criteria to define what constitutes a rainfall event are not yet clearly established in literature. Although we can find detailed, a posteriori, studies about specific torrential rainfall events related to floods in a given basin, detection of rainfall events with a hydrological meaning from daily rainfall records remains difficult and normally has been done with reference to floods events at catchment level. This paper proposes criteria for selecting rainfall events with hydrological objectives. We consider not only events that can produce major floods but also those events around the runoff generation threshold which can also produce significant contributions to the subsurface flow. These criteria have been applied to the territory of the River Júcar Water Authority (43.000 km2), using daily data recorded by the Automatic Hydrological Information System (SAIH), and covering a 15 year period (1989-2003). A total of 347 events were identified and characterised by indicators of total rainfall, duration, intensity and irregularity calculated over 11 regional units. The synoptic atmospheric situation responsible for each episode has also been taken into account in the analysis. As a result, a classification of the episodes has been obtained. The analysis shows a littoral-interior dichotomy. The largest number of events were recorded near the coast (except in one region), mostly in winter, with greatest volumes and high irregularity. In the interior the events were less intense and more frequent in summer. The orographic effect is important, not just in relation to altitude but also in relation to the orientation of the mountain ranges with respect to the wind direction

The effect of observation timescales on the characterisation of extreme Mediterranean precipitation

This paper analyses the behaviour of five rainfall indicators (maximum intensity, cumulative rainfall, irregularity, probability of rain and persistence of rain) over different observation timescales ranging from 5 min to 24 h. It covers a large area on the Mediterranean side of the Iberian Peninsula (River J´ucar Water Authority, 43 000 km2) on a continuous basis over a period of 14 years (19942007). The results show that the behaviour of extreme Mediterranean rainfall is heavily dependent on the observation timescale. There are a number of turning points in the indicator trends which occur on different timescales (1 and 6 h in the case of rain intensity and irregularity, 6 h for cumulative rainfall and between 15 and 30 min for the persistence of rain) and may be relevant for the determination of thresholds used in wáter management

Evolución de los usos terciarios del suelo en la Ciutat Vella de València (1900-2002)

El casco antiguo de la ciudad de Valencia conoció a lo largo del siglo XX importantes modificaciones en sus estructuras demográfica y funcional. Determinados enclaves fueron objeto, también, de alteraciones en su trama urbana. Los equipamientos terciarios repartidos entre los seis barrios que integra el distrito de Ciutat Vella, han cambiado cualitativa y cuantitativamente, al compás de las transformaciones en la oferta y la demanda. Mientras algunos muestran un claro retroceso en su cuota de establecimientos comerciales y de servicios, otros -Sant Francesc, El Mercat- se convierten en los principales exponentes de la terciarización de este ámbito urbano consolidado