Search results for "Monitoring program"
showing 5 items of 25 documents
The rapid atmospheric monitoring system of the Pierre Auger Observatory
2012
The Pierre Auger Observatory is a facility built to detect air showers produced by cosmic rays above 1017 eV. During clear nights with a low illuminated moon fraction, the UV fluorescence light produced by air showers is recorded by optical telescopes at the Observatory. To correct the observations for variations in atmospheric conditions, atmospheric monitoring is performed at regular intervals ranging from several minutes (for cloud identification) to several hours (for aerosol conditions) to several days (for vertical profiles of temperature, pressure, and humidity). In 2009, the monitoring program was upgraded to allow for additional targeted measurements of atmospheric conditions shor…
VLBA polarimetric monitoring of 3C 111
2018
Context. While studies of large samples of jets of active galactic nuclei (AGN) are important in order to establish a global picture, dedicated single-source studies are an invaluable tool for probing crucial processes within jets on parsec scales. These processes involve in particular the formation and geometry of the jet magnetic field as well as the flow itself. Aims. We aim to better understand the dynamics within relativistic magneto-hydrodynamical flows in the extreme environment and close vicinity of supermassive black holes. Methods. We analyze the peculiar radio galaxy 3C 111, for which long-Term polarimetric observations are available. We make use of the high spatial resolution of…
Development of Beach Litter Monitoring on the Latvian Coastline: the Citizen Science Perspective
2021
The research analyses the beach litter monitoring programme in Latvia and provides suggestions for its improvement seeking to provide necessary information for effective marine litter management on the Latvian coastline of the Baltic Sea. The beach litter monitoring programme has been enacted since 2012 by NGO “FEE Latvia” and current research has been focused on the situation assessment and particularly provides analyses on a number and distribution of the surveyed beaches, the frequency and timing of the monitoring, litter classification and counting methodology, as well as the possible programme development using the NGO work based on the citizen science approach. The results allow to el…
Sub-milliarcsecond imaging of a bright flare and ejection event in the extragalactic jet 3C 111
2020
Context. Flares in radio-loud active galactic nuclei are thought to be associated with the injection of fresh plasma into the compact jet base. Such flares are usually strongest and appear earlier at shorter radio wavelengths. Hence, very long baseline interferometry (VLBI) at millimeter(mm)-wavelengths is the best-suited technique for studying the earliest structural changes of compact jets associated with emission flares. Aims. We study the morphological changes of the parsec-scale jet in the nearby (z = 0.049) γ-ray bright radio galaxy 3C 111 following a flare that developed into a major radio outburst in 2007. Methods. We analyse three successive observations of 3C 111 at 86 GHz with th…
Ambrosia trifida L. in France: current distribution and ecological knowledge. Towards an eradication of the species?
2014
National audience; Giant ragweed (Ambrosia trifida L.) is an annual plant belonging to Asteraceae, originating from North America. It was introduced in France in the early twentieth century. Originally described as a ruderal plant, Ambrosia trifida was recently reported in agricultural areas (maize and soybean) in the region Midi-Pyrénées. Beyond the potential public health issue, this species is a major invasive weed in North America, its native area. That is why a question arises about the future trend of the species in France. Can we expect a low ability of the species to adapt the French habitats and land-uses, with a low probability of naturalization? Viceversa, should we consider lead…