Search results for "satellite"

Geographical patterns of genetic variation in rosemary (Rosmarinus officinalis) in the Mediterranean basin

2013

Climate changes during the Quaternary had important effects on the evolution of European plant species. The distribution of genetic variability in rosemary, a strictly Mediterranean species of reputed Plio-Quaternary origin for which the diversification centre is hypothesized to be located in the western part of the Mediterranean basin, was investigated across the species range by using plastid microsatellites (plastid simple sequence repeat (cpSSR)) markers. Seven out of the 17 primer pairs screened were polymorphic, with up to four alleles, yielding a total of 17 size variants combined into ten haplotypes. A permutation test to investigate for geographical structure showed no significant …

Monitoring water stress in Mediterranean semi-natural vegetation with satellite and meteorological data

2014

In arid and semi-arid environments, the characterization of the inter-annual variations of the light use efficiency ε due to water stress still relies mostly on meteorological data. Thus the GPP estimation based on procedures exclusively driven by remote sensing data has not found yet a widespread use. In this work, the potential to characterize the water stress in semi-natural vegetation of three spectral indices (NDWI, SIWSI and NDI7) – from MODIS broad spectral bands – has been analyzed in comparison to a meteorological factor (Cws). The study comprises 70 sites (belonging to 7 different ecosystems) uniformly distributed over Tuscany, and three eddy covariance tower sites. An operational…

Mapping wild pear trees (Pyrus bourgaeana) in Mediterranean forest using high-resolution QuickBird satellite imagery

2012

Recent advances in spatial and spectral resolution of satellite imagery as well as in processing techniques are opening new possibilities of fine-scale vegetation analysis with interesting applications in natural resource management. Here we present the main results of a study carried out in Sierra Morena, Cordoba southern Spain, aimed at assessing the potential of remote-sensing techniques to discriminate and map individual wild pear trees Pyrus bourgaeana in Mediterranean open woodland dominated by Quercus ilex . We used high spatial resolution 2.4 m multispectral/0.6 m panchromatic QuickBird satellite imagery obtained during the summer of 2008. Given the size and features of wild pear tr…

The size distribution of marine atmospheric aerosol with regard to primary biological aerosol particles over the South Atlantic Ocean

1999

Abstract The marine atmosphere is characterized by particles which originate from the ocean and by those which reached the air by advection from the continent. The bubble-burst mechanism produces both sea salt as well as biological particles. The following article describes the determination of the size distribution of marine aerosol particles with special emphasis on the biological particles. Th data were obtained on three cruises with the German Research Vessel “METEOR” crossing the South Atlantic Ocean. The measurements showed that biological particles amount to 17% in number and 10% in volume concentration. Another type of particle became obvious in the marine atmosphere, the biological…

Spanish Photographic Meteor Network: An interdisciplinary crosslink

2001

This paper reports the birth of the Spanish Photographic Meteor Network (SPMN), a project that began their activities in 1997 through professional and amateur astronomers, coinciding with the high activity associated to several stream’s outbursts. One of the objectives of the network is to develop a continuous fireball monitoring in Spain and to obtain orbital and chemical information on meteoroids. Today the SPMN is a solid project under the auspices of three Universities (University Jaume I, University of Valencia and University of Barcelona) and one Space Institute (Catalonian Institute for Space Studies). The National Institute for Aerospace Research (INTA) and the Scientific Research C…

Leonid fluxes: 1994-1998 activity patterns

2001

Abstract-The Leonid meteor shower was observed worldwide in 1998 November in an intensive campaign without precedent. During this international effort -35 500 meteors were reported by members and collaborators of the International Meteor Organization (IMO) using a standard methodology. Despite the absence of a meteor storm in 1998, the rich observational data allow us to obtain a detailed unprecedented knowledge of the stream structure between 1994 and 1998. INTRODUCTION We present here the results from long-term visual monitoring by members and collaborators of the International Meteor Organization (IMO) and photographic and charge-coupled device (CCD) monitoring research obtained by membe…

A Dutch contribution to early interpretations of Meteor Crater, Arizona, USA – Marten Edsge Mulder’s ignored 1911 paper

2018

Abstract Following the first scientific descriptions in the late nineteenth century, the origin of the curious structure currently known as Meteor Crater (or Barringer Crater) in Arizona (USA) remained controversial until well into the twentieth century. Within the context of commercial mining, Daniel Moreau Barringer’s view that it recorded a substratum-penetrative meteorite impact (with the cosmic body still preserved) was commonly discarded. Marten Edsge Mulder (1847–1928), Dutch professor of medicine, found fault with Barringer’s non-explosive model. In 1911, Mulder advanced, in an ignored paper written in Dutch, a novel model of an explosive meteorite (‘meteor’ in Mulder’s terminology)…

The METEOR Trial: The Burial of Methotrexate in Ulcerative Colitis?

2016

Comparison of evapotranspiration estimates by NOAA-AVHRR images and aircraft flux measurements in a semiarid region of Spain.

1998

Abstract This paper is intended to show how to aggregate two different remote-sensing techniques carried out in the framework of the European-Union funded project EFEDA (European Field Experiment in a Desertification-threatened Area). One of these is based on satellite measurements, and the other on aircraft flux measurements. The aim of putting together both methodologies was to determine regional evapotranspiration as a major component of the water balance in Castilla-La Mancha, a semiarid region in southeast Spain. The basis for the satellite approach is using temperature information collected by the Advanced Very High-Resolution Radio- meter (AVHRR) sensor on board the National Oceanic …

A method for the atmospheric correction of ENVISAT/MERIS data over land targets

2007

An atmospheric correction algorithm for the retrieval of land surface reflectance from imagery acquired by the Medium Resolution Imaging Spectrometer (MERIS) on-board the European Space Agency (ESA) ENVIronmental SATellite (ENVISAT) platform has been implemented. The algorithm is designed to estimate the main atmospheric parameters needed in the correction, aerosol and water vapour contents, from the image itself, leading to an optimal characterization of the atmospheric state at the time of image acquisition. Once the atmospheric state has been defined, a second step deals with the retrieval of surface reflectance, accounting for the contribution of surface elevation and roughness as well …