Winds from visible (513 nm) images obtained by the Venus Express Monitoring Camera

Abstract

International audienceLong-term observations of Venus by the Venus monitoring camera (VMC) [4] onboard Venus Express in the visible range (513 nm) allowed to obtain information on circulation in the middle of Hadley cell. Here we present preliminary results of wind tracking of visible images obtained by VMC in the period 2007/07/01-2013/01/29. The mean zonal speed in middle latitudes (30-65ºS) is monotonously changing with latitude-76.5 to-61.5 m/s. In low latitudes (10-20ºS) zonal speed is about-82 m/s. Differences in the behavior of the meridional component in low and middle latitudes indicate that different cloud layers are observed in the visible range (513 nm). The mean horizontal flow demonstrates a dependence on local solar time. Moreover, the nature of diurnal variations is different for low and middle latitudes. Following Bertaux et al. [1] the mean horizontal flow in the middle of Hadley cell show a connection with the underlying topography