Search results for "CLIMATE"
showing 10 items of 4934 documents
Chemostratigraphy, magnetostratigraphy, chronology, palaeoenvironments and correlations.
2013
4 pages
The role of Mediterranean wetlands in climate regulation and greenhouse gases exchanges: from carbon biogeochemistry to European water and nature Dir…
2022
Atesa la seua alta activitat biogeoquímica, els aiguamolls són un dels tipus d'ecosistemes més actius en el cicle global del carboni, amb altes taxes d'intercanvi de carboni i de gasos d'efecte hivernacle (GEH), i, per tant, un gran potencial de regulació climàtica. Una de les parts més importants de la biogeoquímica del carboni als aiguamolls està lligada a les taxes metabòliques, a partir del coneixement de les quals es pot determinar un balanç de carboni associat amb el potencial intercanvi de carboni amb l'atmosfera. La seua capacitat per retindre carboni i mitigar el canvi climàtic, o, per contra, d'alliberar més GEH, i contribuir a l'escalfament global, es determina pel balanç de carb…
European phenological response to climate change matches the warming pattern
2006
Global climate change impacts can already be tracked in many physical and biological systems; in particular, terrestrial ecosystems provide a consistent picture of observed changes. One of the preferred indicators is phenology, the science of natural recurring events, as their recorded dates provide a high-temporal resolution of ongoing changes. Thus, numerous analyses have demonstrated an earlier onset of spring events for mid and higher latitudes and a lengthening of the growing season. However, published single-site or single-species studies are particularly open to suspicion of being biased towards predominantly reporting climate change-induced impacts. No comprehensive study or meta-an…
The far south: the Pleistocene–Holocene transition in Nerja Cave (Andalucı́a, Spain)
2002
Abstract The archaeological site of Cueva de Nerja (Malaga, Spain) provides significant data about the bioclimatic conditions of one of the most southern European temperate regions. The bioclimatic and palaeogeographic changes that have occurred during the 20,000 years of human occupation of the site can be analysed by relating the geodynamic processes, the palaeobotany and the palaeofauna recovered from its archaeological deposits.
Tree rings and volcanic cooling
2012
Oxidation, efflux, and isotopic fractionation of methane during autumnal turnover in a polyhumic, boreal lake
2007
[1] We studied the oxidation and efflux of methane (CH4) in a small, polyhumic lake, Mekkojarvi (southern Finland), during 6 weeks in autumn when the stability of the water mass first weakened, temporarily restabilized, and finally mixed completely. During the summer stratification period, CH4 had accumulated in the anoxic hypolimnion to high concentrations (>150 mmol m−3). Gradual mixing of the water column during the autumn allowed access to both oxygen and CH4 by aerobic methane-oxidizing bacteria (MOB) deeper in the water column. Thus the bulk (∼83–88%) of the CH4 accumulated in the hypolimnion was subsequently consumed by MOB while only 12–17% was lost from the lake to the atmosphere a…
A HYDRAULIC CONDUCTIVITY MODEL POINTS TO POST-NEOGENE SURVIVAL OF THE MEDITERRANEAN OLIVE
2004
Research on the subfossil record and paleoecology of Olea europaea suggests a new interpretation of its history and ecology with reference to the Mediterranean climate since the Neogene. New results are based on the wood anatomy of ancient and extant Olea and a model estimating hydraulic conductance established for wild forms belonging to Olea europaea subsp. europaea. These suggest that during glacial periods wild olive populations survived in protected microenvironments, particularly riparian habitats. Thereafter, the postglacial expansion of olive associated with climatic warming took place from these refuge areas. This new evidence suggests that the continued existence of Olea in Medite…
Automatic generation of emissivity maps on a European scale
2009
The remote sensing measurement of the land surface temperature from satellites provides an overview of this magnitude on a continuous and regular basis. The study of its evolution in time and space is a critical factor in many scientific fields such as weather forecasting, detection of forest fires, climate change, and so on. The main problem of making this measurement from satellite data is the need to correct the effects of the atmosphere and the surface emissivity. In this work, these corrections have been made using a split-window algorithm. The aim was to define an enhanced vegetation cover method and develop a system that used it, in order to automatically generate maps of land surfac…
Carbon use efficiency variability from MODIS data
2017
[EN] Carbon use efficiency (CUE) describes how efficiently plants incorporate the carbon fixed during photosynthesis into biomass gain and can be calculated as the ratio between net primary production (NPP) and gross primary production (GPP). In this work, annual CUE has been obtained from annual GPP and NPP MODIS products for the peninsular Spain study area throughout eight years. CUE is spatially and temporally analyzed in terms of the vegetation type and annual precipitation and annual average air temperature. Results show that dense vegetation areas with moderate to high levels of precipitation present lower CUE values, whereas more arid areas present the highest CUE values. However, th…
Storm Energy Flux Characterization along the Mediterranean Coast of Andalusia (Spain)
2019
This paper investigates wave climate and storm characteristics along the Mediterranean coast of Andalusia, for the period 1979&ndash