HR: 0830h
AN: P51C-0460    [PDF]
TI: Cloud-tracked winds for the first Mars Global Surveyor Mapping year
AU: * Wang, H (
EM: hqw@gps.caltech.edu
AF: CALTECH, 150-21 CALTECH, Pasadena, CA 91106
AU: Ingersoll, A P
EM: api@gps.caltech.edu
AF: CALTECH, 150-21 CALTECH, Pasadena, CA 91106
AB: We have measured winds using cloud motion in consecutive Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) wide-angle global map swaths taken during the first mapping year (Ls 135$\deg$-360$\deg$-111$\deg$). We present a total of ~11,200 wind vectors collected in the north polar region during Ls 135$\deg$-195$\deg$ (late summer/early fall) and Ls 20$\deg$-55$\deg$ (mid spring), and in the south polar region during Ls 337$\deg$-10$\deg$ (late summer/early fall). For cases with good coverage, we also present the derived mean zonal and meridional winds and the circulation pattens. The speed of the zonal winds in 60$\deg$N-70$\deg$N increases at ~0.6 m/s/$\deg$Ls in late northern summer, and that in 60$\deg$S-70$\deg$S increases at ~0.7 m/s/$\deg$Ls in late southern summer. The latitudinal distribution of zonal wind within 50$\deg$N-75$\deg$N from mid northern summer to early northern fall indicates that winds at higher latitudes are generally weaker than those at lower latitudes, but the rate of increase with time is faster at higher latitudes. There is a cyclonic gyre in the 90$\deg$W-0$\deg$-30$\deg$E sector in the north polar region. The cloud-tracked winds in the north are compared with the winds simulated by the GCMs and with the gradient winds derived from MGS Thermal Emission Spectrometer (TES) data.
DE: 5409 Atmospheres--structure and dynamics
SC: Planetary Sciences [P]
MN: 2003 Fall Meeting