NCAR Visitor Center - One-Day Closure - Saturday 10/25 more info>
- UCAR Home
- About Us
- For Staff
Time: 9:30–10:30 a.m.
Date: Monday, April 14, 2014
Location: 9:30-10:30 CG-1, North Auditorium (also webcast at http://www.fin.ucar.edu/it/mms/cg-live.htm)
Title: Upper Atmospheric Wind Observation Research at NCAR/HAO
NCAR HAO has been conducting Fabry-Perot interferometer (FPI) observations of mesospheric and thermospheric winds from ground-based, balloon-borne, and spaceborne platforms. The goals of these observations are for mesospheric and thermospheric dynamics studies. In this talk, results from the first balloon-borne FPI observation will be presented. Stratospheric balloon-borne instrument can fly at ~40 km, where the Rayleigh scattering of the sunlight is significantly lower than that at sea level. Consequently, the balloon-borne instrument is capable of observing daytime airglow emission for Doppler wind measurement. The NASA-sponsored balloon-borne FPI called HIWIND flew from Kiruna, Sweden, on June 14, 2011. One of the major findings of HIWIND observations was persistent equatorward thermospheric winds. The NCAR thermosphere ionosphere model TIEGCM predicted mostly poleward winds on the dayside contrary to the observation. Further investigation with the TIEGCM showed that all equatorward winds could be achieved by enhanced heating in the cusp region. While HAO is pursuing more balloon and satellite opportunities, it is also expanding ground-based FPI observations from the Arctic to Antarctica. An overview of these ground-based instrument projects will be given. In addition, NCAR was the PI institute for the NASA TIMED satellite TIDI instrument. For over a decade, the TIDI instrument has provided the only global wind observation for the mesospheric dynamics studies and invaluable validations for various NCAR ionosphere thermosphere models (TIEGCM, WACCM, and TIMEGCM). The TIDI wind data also became the driver for the NCAR TIEGCM, providing more realistic mesospheric forcing for the thermosphere and ionosphere simulations. Simulations with this new driver have made the ionospheric current results agree much better with observations.