Location
Yosemite National Park
Start Date
2-12-2014 8:35 AM
End Date
2-12-2014 9:05 AM
Description
Ionospheric density often exhibits significant variations, which affect the propagation of radio signals that pass through or are reflected by the ionosphere. One example of these effects is the loss of phase lock and range errors in Global Navigation Satellite Systems (GNSS) signals. Because our modern society increasingly relies on ground-toground and ground-to-space communications and navigation, understanding the sources of the ionospheric density variation and monitoring its dynamics during space weather events have great importance. Storm-enhanced density (SED) is one of the most prominent ionospheric density structures that can have significant space weather impact. In this presentation, we present multi-instrument observations and modeling results of the SED events, focusing on the formation processes. Formation and the subsequent evolution of the SED and the mid-latitude trough are revealed by global GPS vertical total electron content (VTEC) maps. High time resolution Poker Flat Advanced Modular Incoherent Scatter Radar (PFISR) observations are used to reveal the ionospheric characteristics within the SED when available. In addition, field-aligned current data from Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) and large-scale convection flow pattern measured by the Super Dual Auroral Radar Network (SuperDARN) will also be used to provide large-scale context. Based on these observations, we will discuss the role of energetic particle precipitation, enhanced thermospheric wind, and enhanced convection flows, including subauroral polarization streams (SAPS), in creating the SED. In the modeling part, we use the Global Ionosphere Thermosphere Model (GITM) to study the SED formation. Various high-latitude drivers, such as the potential patterns from the Weimer model, outputs from the Assimilative Mapping of Ionospheric Electrodynamics (AMIE) and the Hot Electron Ion Drift Integrator Model (HEIDI) are used to drive GITM. Effects of different drivers as well as different physical processes on creating SEDs are assessed.
Formation of Storm Enhanced Density (SED) during Geomagnetic Storms: Observation and Modeling Study
Yosemite National Park
Ionospheric density often exhibits significant variations, which affect the propagation of radio signals that pass through or are reflected by the ionosphere. One example of these effects is the loss of phase lock and range errors in Global Navigation Satellite Systems (GNSS) signals. Because our modern society increasingly relies on ground-toground and ground-to-space communications and navigation, understanding the sources of the ionospheric density variation and monitoring its dynamics during space weather events have great importance. Storm-enhanced density (SED) is one of the most prominent ionospheric density structures that can have significant space weather impact. In this presentation, we present multi-instrument observations and modeling results of the SED events, focusing on the formation processes. Formation and the subsequent evolution of the SED and the mid-latitude trough are revealed by global GPS vertical total electron content (VTEC) maps. High time resolution Poker Flat Advanced Modular Incoherent Scatter Radar (PFISR) observations are used to reveal the ionospheric characteristics within the SED when available. In addition, field-aligned current data from Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) and large-scale convection flow pattern measured by the Super Dual Auroral Radar Network (SuperDARN) will also be used to provide large-scale context. Based on these observations, we will discuss the role of energetic particle precipitation, enhanced thermospheric wind, and enhanced convection flows, including subauroral polarization streams (SAPS), in creating the SED. In the modeling part, we use the Global Ionosphere Thermosphere Model (GITM) to study the SED formation. Various high-latitude drivers, such as the potential patterns from the Weimer model, outputs from the Assimilative Mapping of Ionospheric Electrodynamics (AMIE) and the Hot Electron Ion Drift Integrator Model (HEIDI) are used to drive GITM. Effects of different drivers as well as different physical processes on creating SEDs are assessed.