[1] Variations of vertical air velocity (W) in the midlevel shallow-layer clouds are described by a case study observed at West Sumatra, Indonesia (0.2°S, 100.32°E), in the nighttime between 8 and 9 May 2004. By receiving echoes from refractive index irregularities, W and spectral width (s W ), used as a proxy of W turbulence, were observed both in clear and cloud regions using frequency power spectrum obtained by a 47-MHz wind profiler with 150-m vertical and 166-s time resolutions. Using altitude profiles of received signal intensity of a 532-nm Mie lidar (P lidar ), altitudes with significantly larger P lidar than below (or above) were considered as cloud regions. Most of the shallow-layer clouds were observed between 6.0 and 8.5 km. In the top part of clouds ($0-500 m below the estimated cloud tops), downward W up to $0.2-0.3 m s À1 and s W up to $0.5-0.6 m s À1were observed. In the middle part of clouds ($500-1000 m below the estimated cloud tops), W showed large variations. Both the standard deviation of W during the observation period and s W were large ($0.5-0.7 m s À1). These results demonstrate that a combination of VHF wind profiler and lidar is useful to observe wind variations in and around midlevel shallow-layer clouds with high time and vertical resolutions. Altitude profiles of temperature observed by radiosondes showed that the air was absolutely stable near the top part of clouds and conditionally stable below. Possible relationship between W and temperature is discussed.

Using a 46.5-MHz atmospheric radar referred to as the MU radar (MUR) and a Raman/Mie lidar installed at the Shigaraki (34• 51 N, 136• 06 E), continuous wind motions around the tops of the midlatitude cirrus are described for the first time. The cloud system extended from the northeast to southwest (35• N-50• N) along the eastward-moving trough and passed over Shigaraki in the nighttime between 5-6 November 2004. Cloud-top altitude observed by the lidar was located at ∼10.6 km around 1900 LST 5 November, then gradually descended to ∼8.4 km around 0500 LST 6 November. The westerly wind observed by MUR with 12-min and 150-m resolutions showed a rapid increase with altitude around the cloud tops and was almost always larger than 25 m s −1 above ∼1 km higher than the cloud tops. Objective reanalysis showed that a subtropical jet whose core existed to the south of Shigaraki caused a synoptic-scale vertical increase in the westerly wind around the cloud tops. Radiosondes observed a significant vertical increase of potential temperature (greater than 4 K within several hundred meters) around the cloud tops. MUR successfully observed fine time and altitude variations of winds which showed a good correspondence with the descending cloud tops.