Ludger Scherliess & Maura Hagan

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The ionosphere is a region of Earth’s upper atmosphere that is embedded in the thermosphere and parts of the exosphere and mesosphere. The ionosphere is a layer of electrons and electrically charged atoms and molecules that are created by atmospheric absorption of solar radiation. It is subdivided into many layers but for this report, only the F-layer will be of interest. In the F-layer, extreme ultraviolet (EUV) solar radiation ionizes atomic oxygen and in this layer, an intriguing feature occurs. This feature involves an anomalous evening phenomenon over a fixed geographic location, where the electron density during the nighttime is more than twice as large than at noon. This phenomenon takes place during the summer and is visible in the southern hemisphere. This intriguing phenomenon is known as the Weddell Sea Anomaly (WSA).

In an effort to understand this anomalous phenomenon, we investigated whether the Thermosphere-Ionosphere-Electrodynamic General Circulation Model (TIE-GCM) could successfully replicate the WSA observations. TIE-GCM is available for runs-on-request at the Community Coordinated Modeling Center (CCMC). Using the CCMC, we preformed TIE-GCM model runs for the conditions foreseeable for the development of the WSA. MATLAB was used to illustrate output data from TIE-GCM. The data obtained from TIE-GCM was also compared and contrasted to other empirical based model data such as: Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) and Mass-Spectrometer-Incoherent-Scatter (MSIS) E-90 for further investigation of TIE-GCM’s ability to replicate the WSA.

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