Thermospheric Geo-effectiveness of Solar Wind Disturbances Monitored with Low Earth Orbit Measurements of Magnetic Perturbations and Poynting Flux
Abstract
Predicting the Earth's upper atmosphere neutral density response to solar disturbances is an enterprise with a multi-decadal history. Between the mid-1960s and the early-2000's prediction efforts centered on observing and forecasting: 1) the solar F10.7 cm radio flux as a proxy for extreme ultraviolet forcing of the upper atmosphere; and 2) the Ap index as an indicator of the level of geomagnetic forcing in the auroral zones. In the last decade new methods of space- and ground-based monitoring have roughly halved the overall error in satellite location prediction. However, the geomagnetic influence on neutral density disturbances, and associated satellite drag position errors, is still a forecasting challenge. In this presentation we reveal how data from the Defense Meteorological Satellite Program (DMSP) space environment sensors and model-data comparisons with simulations from the OpenGGCM provide new insights into the influence of shock-enhanced solar wind plasma and interplanetary magnetic field (IMF), especially the IMF By-component. In particular, we focus on a class of poorly forecast neutral density enhancements for which the DMSP observations show previously unmeasured, multi-hour Poynting flux deposition in the intervals ahead of dual pulses of global neutral density perturbations. Further, we show that space-based magnetic measurements from low-Earth orbit provide improved indicators of enhanced magnetosphere-ionosphere-thermosphere coupling leading up to such events. We advocate for these space-based measurements as an improvement in monitoring capability, compared to the current suite of geomagnetic indices.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFMSM41D..05K
- Keywords:
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- 0358 ATMOSPHERIC COMPOSITION AND STRUCTURE / Thermosphere: energy deposition;
- 2736 MAGNETOSPHERIC PHYSICS / Magnetosphere/ionosphere interactions;
- 7924 SPACE WEATHER / Forecasting;
- 7954 SPACE WEATHER / Magnetic storms