Physics
Scientific paper
Dec 2001
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2001agufmsa21a..03p&link_type=abstract
American Geophysical Union, Fall Meeting 2001, abstract #SA21A-03
Physics
0310 Airglow And Aurora, 2788 Storms And Substorms, 3369 Thermospheric Dynamics (0358)
Scientific paper
Observations from the recent ARIA (Atmospheric Response in Aurora) campaigns demonstrate phenomena in the region of the recovery phase postmidnight diffuse aurora which are not well explained. Strong zonal winds are observed, with a great deal of vertical structure and large vertical wind shears. These shears are sometimes unstable, with a Richardson number, Ri, less than 0.25. A strong maximum in the horizontal wind in the 110 to 120 km altitude range is a feature of the ARIA measurements, and is not well understood. Significant composition changes are also seen in the ARIA observations, associated with localized heating events, and these composition changes may be related to the measured instabilities. The effects of shears and instabilities may be important for winds, temperature, composition, and wave generation in the thermosphere. Simulations have been performed using a 3-dimensional time-dependent regional scale model recently developed at UCLA. The model is composition-dependent, non-hydrostatic, and high resolution, enabling the model to simulate phenomena which vary rapidly in the zonal direction and on small spacial scales, such as the shears and instabilities seen in the ARIA measurements. Auroral forcing has been introduced for time intervals of 1 to 3 hours, and model results show large wind velocities, which may be accompanied by large shears, and a maximum in the horizontal winds is produced around 110 to 120 km. Experiments have been performed with varying resolutions and auroral input parameters, and unstable regions with Ri less than 0.25 can be produced in the region of large wind shears for auroral forcing parameters within observed values. The ARIA campaigns provide simultaneous measurements of a range of atmospheric quantities, including the structure and magnitude of auroral forcing parameters in the region of the postmidnight diffuse aurora. These measurements are able to provide inputs to the model and the simulated response of the thermosphere to the auroral forcing is compared with ARIA observations.
Jones Peter W.
Lyons Larry R.
Parish Helen F.
No associations
LandOfFree
Investigations of the Thermospheric Response to the Diffuse Aurora Using a 3-D High Resolution Model does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Investigations of the Thermospheric Response to the Diffuse Aurora Using a 3-D High Resolution Model, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Investigations of the Thermospheric Response to the Diffuse Aurora Using a 3-D High Resolution Model will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1378762