The profiles are consistent and smooth in the convective boundary layer. Wide deviations at higher altitudes are generally due to the lack of backscatter data when low clouds block the lidar signal or lack of aerosol structures in the free atmosphere. In strong convection, the aerosols rise up several kilometers and the wind profiling is successful for the chosen 2 km vertical range. Summary of hourly averaged, noon wind profiles from FIFE program. Figure 39 shows an example of wind profiles with different averaging intervals on July 27, 1989.
Wind speed decreases close to ground due to surface friction.
The 3-minute wind profiles show fluctuations above 1.4 km, since clouds partly blocked the scan. When averaging time increases, the fluctuations decrease and the wind profiles become smoother. The 3-minute profiles have instabilities in wind speed and direction near 600 m. Error bars show RMS errors of the estimates. Return to the Index .