Found 4 results
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2020
Authors: Krasnoselskikh V., Larosa A., Agapitov O., de Wit Dudok, Moncuquet M., et al.
Title: Localized Magnetic-field Structures and Their Boundaries in the Near-Sun Solar Wind from Parker Solar Probe Measurements
Abstract:

One of the discoveries of the Parker Solar Probe during its first encounters with the Sun is ubiquitous presence of relatively small-scale structures standing out as sudden deflections of the magnetic field. They were named "switchbacks" since some of them show a full reversal of the radial component of the magnetic field and then return to "regular" conditions. We carried out an analysis of three typical switchback structures having different characteristics: I. Alfvénic structure, where the variations of the magnetic field components take place while conserving the magnitude of the magnetic field; II. Compressional structure, where the magnitude of the field varies together with changes of its components; and III. Structure manifesting full reversal of the magnetic field, presumably . . .
Date: 04/2020 Publisher: The Astrophysical Journal Pages: 93 DOI: 10.3847/1538-4357/ab7f2d Available at: https://iopscience.iop.org/article/10.3847/1538-4357/ab7f2d
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2019
Authors: Scudder J. D.
Title: The Long-standing Closure Crisis in Coronal Plasmas
Abstract:

Coronal and solar wind physics have long used plasma fluid models to motivate physical explanations of observations; the hypothesized model is introduced into a fluid simulation to see if observations are reproduced. This procedure is called Verification of Mechanism (VoM) modeling; it is contingent on the self consistency of the closure that made the simulation possible. Inner corona VoMs typically assume weak gradient Spitzer─Braginskii closures. Four prominent coronal VoMs in place for decades are shown to contradict their closure hypotheses, demonstrably shaping coronal and solar wind research. These findings have been possible since 1953. This unchallenged evolution is worth understanding, so that similarly flawed VoMs do not continue to mislead new research. As a first step in t. . .
Date: 11/2019 Publisher: The Astrophysical Journal Pages: 148 DOI: 10.3847/1538-4357/ab48e0 Available at: https://iopscience.iop.org/article/10.3847/1538-4357/ab48e0
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2017
Authors: Reid Hamish A. S., and Kontar Eduard P.
Title: Langmuir wave electric fields induced by electron beams in the heliosphere
Abstract:

Solar electron beams responsible for type III radio emission generate Langmuir waves as they propagate out from the Sun. The Langmuir waves are observed via in situ electric field measurements. These Langmuir waves are not smoothly distributed but occur in discrete clumps, commonly attributed to the turbulent nature of the solar wind electron density. Exactly how the density turbulence modulates the Langmuir wave electric fields is understood only qualitatively. Using weak turbulence simulations, we investigate how solar wind density turbulence changes the probability distribution functions, mean value and variance of the beam-driven electric field distributions. Simulations show rather complicated forms of the distribution that are dependent upon how the electric fields are sampled. Ge. . .
Date: 02/2017 Publisher: Astronomy & Astrophysics Pages: A44 DOI: 10.1051/0004-6361/201629697 Available at: http://www.aanda.org/10.1051/0004-6361/201629697http://www.aanda.org/10.1051/0004-6361/201629697/pdf
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2003
Authors: ZALDIVAR J
Title: Long-term simulation of main biogeochemical events in a coastal lagoon: Sacca Di Goro (Northern Adriatic Coast, Italy)
Abstract:

A biogeochemical model for the Sacca di Goro Lagoon has been developed and partially validated with field data from 1989 to 1998. The model considers the nutrient cycles in the water column as well as in the sediments. Furthermore, phytoplankton, zooplankton, and Ulva sp. dynamics, as well as shellfish farming, are taken into account. Due to the recent anoxic crises in the lagoon, the dynamic of oxygen has also been simulated. The actual version of the model is a 0D with input fluxes from the watershed and exchange with the Northern Adriatic Sea. Nutrients from the watershed, wet and dry deposition, temperature, light intensity, wind speed and shellfish production are considered as forcing functions. The results show that the model is able to capture the essential dynamics of the lagoon. . .
Date: 11/2003 Publisher: Continental Shelf Research Pages: 1847 - 1875 DOI: 10.1016/j.csr.2003.01.001 Available at: http://linkinghub.elsevier.com/retrieve/pii/S027843430300150Xhttp://api.elsevier.com/content/article/PII:S0278-4343(03)00150-X?httpAccept=text/xmlhttp://api.elsevier.com/content/article/PII:S0278-4343(03)00150-X?httpAccept=text/plain
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