Search results for "rowing"
showing 10 items of 286 documents
The global forest above-ground biomass pool for 2010 estimated from high-resolution satellite observations
2021
Funding Information: We are thankful to the GlobBiomass project team and Frank Martin Seifert (ESA) for valuable suggestions and stimulating scientific discussions. We are thankful to Takeo Tadono (JAXA EORC), Masato Hayashi, (JAXA EORC), Kazufumi Kobayashi (RESTEC), Åke Rosenqvist (soloEO), and Josef Kellndorfer (EBD) for support with the use and interpretation of the ALOS PALSAR mosaics. Support by the CCI Land Cover project team, in particular Sophie Bontemps (UCL), is greatly acknowledged. The help from Martin Jung (MPI-BGC) in feature selection and Ulrich Weber (MPI-BGC) for data processing for the GSV-to-AGB conversions is greatly acknowledged. Forest inventory data for the validation…
Vegetation vulnerability to drought in Spain
2014
[EN] Frequency of climatic extremes like long duration droughts has increased in Spain over the last century.The use of remote sensing observations for monitoring and detecting drought is justified on the basis that vegetation vigor is closely related to moisture condition. We derive satellite estimates of bio-physical variables such as fractional vegetation cover (FVC) from MODIS/EOS and SEVIRI/MSG time series. The study evaluates the strength of temporal relationships between precipitation and vegetation condition at time-lag and cumulative rainfall intervals. From this analysis, it was observed that the climatic disturbances affected both the growing season and the total amount of vegeta…
Linking photosynthesis and sun-induced fluorescence at sub-daily to seasonal scales
2018
Abstract Due to its close link to the photosynthetic process, sun-induced chlorophyll fluorescence (F) opens new possibilities to study dynamics of photosynthetic light reactions and to quantify CO2 assimilation rates. Although recent studies show that F is linearly related to gross primary production (GPP) on coarse spatial and temporal scales, it is argued that this relationship may be mainly driven by seasonal changes in absorbed photochemical active radiation (APAR) and less by the plant light use efficiency (LUE). In this work a high-resolution spectrometer was used to continuously measure red and far-red fluorescence and different reflectance indices within a sugar beet field during t…
Modelling soil moisture at SMOS scale by use of a SVAT model over the Valencia Anchor Station
2010
16 páginas, 9 figuras, 5 tablas.
An intractable climate archive — Sclerochronological and shell oxygen isotope analyses of the Pacific geoduck, Panopea abrupta (bivalve mollusk) from…
2008
Abstract Annual growth increment patterns of cardinal teeth (CT) of Panopea abrupta (Conrad) can reportedly provide information about past climate variations. However, little is known about the intra-annual timing and rate of shell growth necessary to interpret such records. In addition, it remains unclear whether actual temperatures can be reliably inferred from δ18O values of geoduck {goo'e-duk} shells. This study compared high-resolution environmental records (hourly to monthly resolved temperature, bi-weekly to monthly δ18Owater and salinity data) with temperatures reconstructed from oxygen isotope values of the outer shell layer (Tδ18OOSL) and cardinal tooth portions (Tδ18OCT) of diffe…
High-resolution sclerochronological analysis of the bivalve mollusk Saxidomus gigantea from Alaska and British Columbia: techniques for revealing env…
2009
Abstract The butter clam, Saxidomus gigantea , is one of the most commonly recovered bivalves from archaeological shell middens on the Pacific Coast of North America. This study presents the results of the sclerochronology of modern specimens of S. gigantea , collected monthly from Pender Island (British Columbia), and additional modern specimens from the Dundas Islands (BC) and Mink and Little Takli Islands (Alaska). The methods presented can be used as a template to interpret local environmental conditions and increase the precision of seasonality estimates in shellfish using sclerochronology and oxygen isotope analysis. This method can also identify, with a high degree of accuracy, the d…
A multiproxy study of Younger Dryas and Early Holocene climatic conditions from the Grabia River paleo-oxbow lake (central Poland)
2015
International audience; A multi-proxy reconstruction of water depth, temperature and precipitation inferred from Cladocera, Chironomidae and pollen assemblages has been obtained from Świerczyna paleo-oxbow (central Poland) during the Younger Dryas (YD) and Early Holocene. Results suggest that the YD was relatively cold and comprised two main phases. The first (ca. 12,500–12,000 cal. yrs BP) is characterized by a continental climatic regime and a decrease in winter temperatures and precipitation but an increase in spring/summer precipitation. The second phase (ca. 12,000–11,500 cal. yrs BP) was more mild with a variable continental climate, an increase in summer and winter temperature, a len…
Venerid bivalve Venus verrucosa as a high-resolution archive of seawater temperature in the Mediterranean Sea
2021
Abstract High-resolution stable isotope data (δ18O, δ13C) were used to study growth strategies of the bivalve Venus verrucosa collected from three sites of the eastern coast of the Adriatic Sea. The principal objectives of this study were to identify the main growing season and to evaluate the potential applicability of δ18Oshell values to reconstruct the seasonal temperature variability. Calcium carbonate for oxygen and carbon isotope analyses was obtained by drilling the outer shell layer. Temporal and spatial variations in temperature and salinity values at the study sites were simulated using the 3D numerical ocean model ROMS. Annual periodicity of growth patterns was confirmed by δ18Os…
Timing and duration of European larch growing season along altitudinal gradients in the Swiss Alps.
2009
The 2007 European larch (Larix decidua Mill.) growing season was monitored along two elevational transects in the Lotschental valley in the Swiss Alps. Phenological observations and weekly microcore sampling of 28 larch trees were conducted between April and October 2007 at seven study sites regularly spaced from 1350 to 2150 m a.s.l. on northwest- and southeast-facing slopes. The developmental stages of nearly 75,000 individual cells assessed on 1200 thin sections were used to investigate the links between the trees' thermal regimes and growth phases including the beginning and ending of cell enlargement, wall thickening and maturation of the stem wood. Needles appeared approximately 3-4 w…
Changes in evapotranspiration and phenology as consequences of shrub removal in dry forests of central Argentina
2014
More than half of the dry woodlands (forests and shrublands) of the world are in South America, mainly in Brazil and Argentina, where in the last years intense land use changes have occurred. This study evaluated how the transition from woody-dominated to grass-dominated system affected key ecohydrological variables and biophysical processes over 20 000 ha of dry forest in central Argentina. We used a simplified surface energy balance model together with moderate-resolution imaging spectroradiometer–normalized difference vegetation index data to analyse changes in above primary productivity, phenology, actual evapotranspiration, albedo and land surface temperature for four complete growing …