Physics-Based Neutral Density Model
Abstract
A data assimilation system for specifying the thermospheric developed over the last several years. The particular benefit creation of a data assimilation system that makes use of a physical model, the Coupled Thermosphere-Ionosphere Model (CTIM) (Fuller-Rowell et al. 1996). The advantage of the physical model, CTIM, over empirical models comes from its ability to represent unclimatological features that are often present during geomagnetic storm conditions. A physical model, like CTIM, in a predictor/corrector-type data assimilation technique like the Kalnan filter, is ideal since the physical model has the ability to provide the best' state of the thermosphere based on conditions at a previous time. Correcting the physical model with observations, in a statistically rigorous manner, provides an optimal method for minimizing the errors while representing the time-dependent conditions of the thermospheric density. Because the thermosphere is strongly driven by external processes, the thrust of the research in the most recent years has focused primarily on improving the specification- of the drivers. It has been shown that improved driver specification can greatly improve accuracy during geomagnetic storms. Improved driver specification has proven itself to be essential since satellite coverage is not globally available at a single epoch and since the upper atmosphere can change much more rapidly in comparison to the satellite revisit rate during geomagnetic storms.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 14, 2005
- Accession Number
- ADA439067
Entities
People
- Tim Fuller-rowell
Organizations
- University of Colorado Boulder