Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 5 of 5
Full-Text Articles in Physics
Timed/Saber Satellite Investigations Of Mesospheric Gravity Wave Variances Over The Andes, Jonathan Pugmire, Michael J. Taylor, Yucheng Zhao, Dominique Pautet, James Russell
Timed/Saber Satellite Investigations Of Mesospheric Gravity Wave Variances Over The Andes, Jonathan Pugmire, Michael J. Taylor, Yucheng Zhao, Dominique Pautet, James Russell
Graduate Student Presentations
Focusing on data from the SABER instrument aboard the TIMED satellite temperature variances are determined as a function of altitude to quantify small scale gravity waves. This was done using IDL software to extract all the temperature profile measurements that were measured by SABER within a limited geographical area, centered on our ground-based optical imager at Cerro Pachon, Chile (30.3°S, 70.7°S). Then large-scale tidal waves, with wavenumbers 0-6, were removed from each profile revealing the gravity wave perturbations. The temperature variance were computed and recorded at several altitudes. Temperature variances reveal possible increased activity due to mountain waves. Mountain waves …
New Measurements Of Mcmurdo Gravity Wave Parameters, Jonathan Pugmire, Michael J. Taylor
New Measurements Of Mcmurdo Gravity Wave Parameters, Jonathan Pugmire, Michael J. Taylor
Graduate Student Presentations
The ANtarctic Gravity Wave Instrument Network (ANGWIN) is an NSF sponsored international program designed to develop and utilize a network of gravity wave observatories using existing and new instrumentation operated at several established research stations around the continent. The primary goal is to better understand and quantify large-scale gravity wave climatology and their effects on the upper atmosphere over Antarctica. ANGWIN currently comprises research measurements from five nations (U.S., U.K., Australia, Japan, and Brazil) at seven international stations. Utah State University’s Atmospheric Imaging Lab operates all-sky infrared and CCD imagers and an Advanced Mesospheric Temperature Mapper (AMTM) imager at several …
Viscous And Induced Current Heating In Plasma Focus Plasmoids, Ahmad Talaei, Eric Lerner
Viscous And Induced Current Heating In Plasma Focus Plasmoids, Ahmad Talaei, Eric Lerner
Graduate Student Presentations
Recently, Abolhasani et al, proposed that the high ion energies observed in plasmoids formed in the plasma focus could be explained by viscous heating. We here elaborate this proposal, demonstrating that during plasmoid formation, ion motion along magnetic field lines can be rapidly converted, at least in part, to thermal energy through viscous diffusion. This effect is strongly enhanced by higher-z ions. We compare the theoretical predictions with the recent observation by Lerner et al, of trapped ion energies of 160 keV. In addition, we propose a second source of heating. The mildly relativistic electron beam emitted by the plasmoid, …
First Year Investigation Of Gravity Waves And Temperature Variability Over The Andes, Jonathan Pugmire, Neal R. Criddle, Michael J. Taylor, Dominique Pautet, Yucheng Zhao
First Year Investigation Of Gravity Waves And Temperature Variability Over The Andes, Jonathan Pugmire, Neal R. Criddle, Michael J. Taylor, Dominique Pautet, Yucheng Zhao
Graduate Student Presentations
The Andes region is an excellent natural laboratory for investigating gravity wave influences on the Upper Mesospheric and Lower Thermospheric (MLT) dynamics: during the summer months the dominant gravity waves result from deep convection arising from severe thunderstorms over the continent to the east. In winter this convective activity is expected to be replaced by strong orographic forcing due to intense prevailing zonal winds blowing eastward from the Pacific Ocean and suddenly encountering the towering Andes mountain range (6000m). This creates large amplitude mountain waves that have been measured well into the stratosphere and most recently penetrate occasionally into the …
The Coefficient Of Bohm Diffusion In Fully Ionized Plasma And Its Theoretical Proof, Ahmad Talaei, Reza Amrollahi
The Coefficient Of Bohm Diffusion In Fully Ionized Plasma And Its Theoretical Proof, Ahmad Talaei, Reza Amrollahi
Graduate Student Presentations
As we know, the classical diffusion can not be able to respond the experimental results of the diffusion in the fully ionized and isothermal plasma. In this article, we purpose to extract the empirical coefficients of the Bohm diffusion and its confinement time, theoretically, in the fully ionized plasma, using the single fluid MHD equations.