HR: 1340h
AN: SA13A-1066    [Abstracts]
TI: Meridional Winds Derived from COSMIC Radio Occultation Measurements
AU: * Luan, X
EM: luanxl@ucar.edu
AF: High Altitude Observatory, National Center for Atmospheric Research, Boulder, CO 80307- 3000, United States
AU: Solomon, S C
EM: stans@ucar.edu
AF: High Altitude Observatory, National Center for Atmospheric Research, Boulder, CO 80307- 3000, United States
AB: Meridional winds derived from F2 layer peak parameters (NmF2 and hmF2) measured by the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) using the servo method, are compared at multiple locations with winds derived from incoherent scatter radar (ISR) and Fabry-Perot interferometer (FPI) measurements. The National Center for Atmospheric Research Thermosphere-Ionosphere-Electrodynamics General Circulation Model (NCAR-TIEGCM) is then employed to simulate the longitudinal variations of meridional winds. Comparisons show that there is generally good agreement between COSMIC winds and ISR, FPI and TIEGCM winds, although COSMIC winds are more equatorward near sunset hours. The COSMIC winds show significant longitudinal variations at latitude 40N (local winter) and 40S (local summer). At 40N, the COSMIC winds exhibit distinct and long duration higher velocity near the midnight hours and during late morning hours within the longitude range 110W to 20W, near the negative declination sector. Similarly, at 40S, the winds are characterized by distinct larger velocity for poleward winds from sunrise to afternoon hours within the longitude range of 120°E to 110°W, near the positive declination sector. At 40°S, another notable feature for the nighttime maximum equatorward winds is seen: there is a local time shift by about 2h from longitude range of 60W to 90E within the negative declination sector to other longitudes within positive declination sector. The NCAR TIEGCM reproduces these longitudinal configurations well, except during the daytime at 40N, and there are some discrepancies in wind magnitude. Analysis of NCAR TIEGCM simulations suggests that the longitudinal variation of meridional winds is mainly controlled by the magnetic declination.
DE: 2427 Ionosphere/atmosphere interactions (0335)
DE: 2437 Ionospheric dynamics
DE: 2443 Midlatitude ionosphere
DE: 2447 Modeling and forecasting
SC: SPA-Aeronomy [SA]
MN: 2007 Fall Meeting