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Full-Text Articles in Physics

Topology Of Earth's Magnetic Shield, David Alan Smith Dec 2017

Topology Of Earth's Magnetic Shield, David Alan Smith

David Smith

The open-closed boundary (OCB) defines the region where geomagnetic field lines transition from being closed to open. Closed field lines have both foot points at or near Earth in opposing hemispheres. Open field lines have one foot point at Earth; the other maps to the interplanetary magnetic field (IMF). Charged particles are able to follow these open field lines into Earth's upper atmosphere. The OCB also defines the polar cap boundary. Being able to identify and track the OCB allows study of several components of the geomagnetic system. Among them are the electrodynamics of the geomagnetic field and the ...


A Review Of High Frequency Radio Wave Absorption, David Alan Smith Dec 2016

A Review Of High Frequency Radio Wave Absorption, David Alan Smith

David Smith

Although the technology dates back nearly to Marconi and his wireless telegraph, the high-frequency (HF) radio spectrum continues to be a useful communications medium.  Since long-distance HF propagation depends on the ionosphere, HF propagation is subject to variations in ionospheric characteristics.  Chief among these characteristics is the density of free electrons.  The sun provides the energy required to ionize neutral atmospheric constituents.  Hence, the production and loss of free electrons is not constant.  Day/night variations as well as the ebb and flow of the 11-year solar cycle cause changes in the density of free electrons.  In addition, space weather ...


Two-Dimensional Electron Gases At The Surface Of Potassium Tantalate, Ben Pound Sep 2014

Two-Dimensional Electron Gases At The Surface Of Potassium Tantalate, Ben Pound

Ben Pound

No abstract provided.


Merrill-Cazier Library Gas Exhibition, Betty Rozum, Andrew Wesolek, Pamela N. Martin Dec 2012

Merrill-Cazier Library Gas Exhibition, Betty Rozum, Andrew Wesolek, Pamela N. Martin

Andrew Wesolek

This exhibition, presented in the Merrill-Cazier Library, captured the history and accomplishments of the GAS program. Click the download button to see a PowerPoint presentation featuring images and text from the exhibition.


Mesosphereic Temperature Variability And Seasonal Characteristics Over The Andes, Jonathan R. Pugmire, Yucheng Zhao, Michael J. Taylor, Dominique Pautet May 2011

Mesosphereic Temperature Variability And Seasonal Characteristics Over The Andes, Jonathan R. Pugmire, Yucheng Zhao, Michael J. Taylor, Dominique Pautet

Jonathan Pugmire

The Utah State University CEDAR Mesospheric Temperature Mapper (MTM) is a high-quality CCD imager capable of remote sensing faint optical emissions from the night sky to determine mesospheric temperature and its variability at an altitude of ~87 km. The MTM was operated at the new Andes Lidar Observatory (ALO)located at Cerro Pachon, Chile (30.2° S, 70.7° W) since August 2009 to investigate the seasonal characteristic of the mesopause at mid-latitudes. Measurement were made alongside a powerful lidar capable of height sounding the mesosphere. In this study, the MTM data have been analyzed to determine night to night ...


The First Ten Months Of Investigation Of Gravity Waves And Temperature Variability Over The Andes., Jonathan R. Pugmire, Neal Criddle, Michael J. Taylor, Dominique Pautet, Yucheng Zhao May 2010

The First Ten Months Of Investigation Of Gravity Waves And Temperature Variability Over The Andes., Jonathan R. Pugmire, Neal Criddle, Michael J. Taylor, Dominique Pautet, Yucheng Zhao

Jonathan Pugmire

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 penetration occasionally into the ...


The First Ten Months Of Investigation Of Gravity Waves And Temperature Variability Over The Andes., Jonathan R. Pugmire, Neal Criddle, Michael J. Taylor, Dominique Pautet, Yucheng Zhao May 2010

The First Ten Months Of Investigation Of Gravity Waves And Temperature Variability Over The Andes., Jonathan R. Pugmire, Neal Criddle, Michael J. Taylor, Dominique Pautet, Yucheng Zhao

Neal R Criddle

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 penetration occasionally into the ...


Intra-Annual Comparison Of Mesospheric Gravity Waves Over Halley And Rothera Stations, Antarctica., Jonathan R. Pugmire, Mike J. Taylor, Kim Nielsen May 2009

Intra-Annual Comparison Of Mesospheric Gravity Waves Over Halley And Rothera Stations, Antarctica., Jonathan R. Pugmire, Mike J. Taylor, Kim Nielsen

Jonathan Pugmire

As part of a collaborative program between British Antarctic Survey and Utah State University, we present an intra-annual study of short-period, mesospheric gravity wave events observed over Antarctica in the near infrared OH emission. The measurements were made using an all-sky airglow imager operated at either Halley Station on the Brunt Ice Shelf, or Rothera Station, situated on the Antarctic Peninsula. A total of six austral winter seasons have been analyzed (2000-2006). This study comprises the first detailed winter seasonal investigation of short-period mesospheric gravity waves at high-Antarctic latitudes. Distributions of their observed wave parameters were found to be similar ...