Search results for "Inde"
showing 10 items of 7365 documents
Rare earth element and neodymium isotope tracing of sedimentary rock weathering
2020
Chemical weathering plays an important role in sequestering atmospheric CO2, but its potential influence on global climate over geological timescales remains debated. To some extent, this uncertainty arises from the difficulty in separating the respective contribution of sedimentary and crystalline silicate rocks to past weathering rates in the geological record; two types of rocks having presumably different impact on the long-term carbon cycle. In this study, we investigate the use of rare earth element (REE) and neodymium isotopes (εNd) in leached iron oxide fractions of river sediments for tracing the origin of weathered rocks on continents. A new index, called ‘concavity index’ (CI), i…
Global-Scale Evaluation of Roughness Effects on C-Band AMSR-E Observations
2015
Quantifying roughness effects on ground surface emissivity is an important step in obtaining high-quality soil moisture products from large-scale passive microwave sensors. In this study, we used a semi-empirical method to evaluate roughness effects (parameterized here by the parameter) on a global scale from AMSR-E (Advanced Microwave Scanning Radiometer for EOS) observations. AMSR-E brightness temperatures at 6.9 GHz obtained from January 2009 to September 2011, together with estimations of soil moisture from the SMOS (Soil Moisture and Ocean Salinity) L3 products and of soil temperature from ECMWF’s (European Centre for Medium-range Weather Forecasting) were used as inputs in a retrieval…
Mercury emissions from soils and fumaroles of Nea Kameni volcanic centre, Santorini (Greece)
2013
There have been limited studies to date targeting mercury emissions from volcanic fumarolic systems, and no mercury flux data exist for soil or fumarolic emissions at Santorini volcanic complex, Greece. We present results from the first geochemical survey of Hg and major volatile (CO2, H2S, H2O and H-2) concentrations and fluxes in the fumarolic gases released by the volcanic/hydrothermal system of Nea Kameni islet; the active volcanic center of Santorini. These data were obtained using a portable mercury spectrometer (Lumex 915+) for gaseous elemental mercury (GEM) determination, and a Multi-component Gas Analyzer System (Multi-GAS) for major volatiles. Gaseous Elemental Mercury (GEM) conc…
A 1286‐year hydro‐climate reconstruction for the Balkan Peninsula
2018
We present a June-July drought reconstruction based on the standardized precipitation index (SPI) for the Balkan Peninsula over the period 730-2015 CE. The reconstruction is developed using a compo ...
Climate indices in historical climate reconstructions: a global state of the art
2021
Narrative evidence contained within historical documents and inscriptions provides an important record of climate variability for periods prior to the onset of systematic meteorological data collection. A common approach used by historical climatologists to convert such qualitative information into continuous quantitative proxy data is through the generation of ordinal-scale climate indices. There is, however, considerable variability in the types of phenomena reconstructed using an index approach and the practice of index development in different parts of the world. This review, written by members of the PAGES (Past Global Changes) CRIAS working group – a collective of climate historians a…
Estimating “land use heritage” to model changes in archaeological settlement patterns
2016
International audience; In this paper, we present a method to calculate a “land use heritage map” based on the concept of “memory of landscape”. Such a map can be seen as one variable among others influencing site location preference, and can be used as input for predictive models. The computed values equate to an index of long-term land use intensity. We will first discuss the method used for creating the land use heritage map, for which kernel density estimates are used.We will then present the use of these land use heritage maps for site location analysis in two study areas in SE France. Earlier analyses showed that the influence of the natural environment on settlement location choice i…
Geographical and bathymetric distribution of foraminiferal assemblages from the Alboran Sea (western Mediterranean)
2018
A total of 176 surface sediment samples, recovered in the Alboran Sea by the oceanographic vessel Vizconde de Eza during the 2002 and 2003 campaigns, were analysed for their foraminiferal content. Planktonic and benthic foraminifera were picked up, studied and classified. In addition, a series of diversity indices were calculated. An attempt was made to correlate diversity (Fisher alpha index) with longitude, latitude and depth. Planktonic assemblages are strongly dominated by the species Globorotalia inflata (d’Orbigny) together with Globigerina bulloides d’Orbigny. Correlation analysis show only a weak relation between planktonic foraminiferal diversity and both longitude and distance to …
Early Diagnosis of Vegetation Health From High-Resolution Hyperspectral and Thermal Imagery: Lessons Learned From Empirical Relationships and Radiati…
2019
[Purpose of Review] We provide a comprehensive review of the empirical and modelling approaches used to quantify the radiation–vegetation interactions related to vegetation temperature, leaf optical properties linked to pigment absorption and chlorophyll fluorescence emission, and of their capability to monitor vegetation health. Part 1 provides an overview of the main physiological indicators (PIs) applied in remote sensing to detect alterations in plant functioning linked to vegetation diseases and decline processes. Part 2 reviews the recent advances in the development of quantitative methods to assess PI through hyperspectral and thermal images.
Biomass and volume modeling in Olea europaea L. cv "Leccino"
2017
Key message: This work demonstrates that the Olive tree, which is managed and pruned as a fruit tree, can be treated as a forest tree using allometric equations, to estimate both biomass production and volumes. Abstract: The Olive tree (Olea europaea L.) is an evergreen tree that can grow and accumulate a relatively high amount of dry matter, even in dry environmental conditions common in the Mediterranean basin and typical of traditional rain-fed agriculture. The objective of this research was to develop a tool to predict woody biomass and tree component volume for the olive tree, to be used for different agricultural and environmental purposes. The study was carried out in six olive grove…
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 …