April 1, 2011, 12:00 pm - 1:00 pm

April 1, 2011, 12:00 pm - 1:00 pm

Ionospheric irregularities and thermosphere-ionosphere coupling in the low- and mid-latitude region

Dr. Tatsuhiro Yokoyama, NASA Goddard Space Flight Center and UMBC/GEST

The Earth's ionosphere in low and middle latitudes is surrounded by closed dipole magnetic fields. It is relatively moderate compared with the high latitude ionosphere, which is coupled with various magnetospheric phenomena. However, irregular density structures induced by plasma instabilities do exist in the lower latitudes, and they affect radio wave propagation and may cause serious communication/navigation error. Furthermore, recent studies have found that neutral atmospheric waves such as tides and gravity waves originated from the tropospheric activity have a significant effect on the formation of the ionospheric structures. Efforts to understand and predict the irregularities and disturbances based on ground-based/airborne observations and numerical modeling will be presented.