4:00 PM - 4:15 PM
[AAS02-09] Analysis of vertical wind velocity in relation to cloud formation by synergetic observation system
Keywords:Doppler lidar, vertical wind, cloud
Vertical air-motion has been recognized to play a major role in cloud formation. Despite the importance, convective vertical velocity has not been directly treated in the most of the GCMs except for some limited studies, e.g., Donner et al., 2001 and Del Genio et al., 2007.
In this study, we have conducted measurements of vertical- and horizontal-wind velocity and cloud base height by the synergetic observation system. Synergetic observation system includes 2µm-coherent Doppler lidar with scanning function, 355-nm Multiple-Field-of-View Multiple scattering polarization lidar (355nm-MFMSPL), 355nm-High-spectral-resolution-lidar (355nm-HSRL) and 94GHz Doppler cloud radar (HG-Spider). We first developed the cloud mask schemes that can be applied to the 2µm-coherent Doppler lidar by using vertical structure of SNR. Then the mask scheme has been evaluated by using the cloud detection results by the 355nm-MFMSPL. Analyses showed that general agreement in cloud mask results between the two lidars has been achieved. Then vertical velocity (w) at cloud bottom height has been analyzed in relation to the estimated turbulence kinetic energy below cloud bottom (TKE). Five-beam-observation-mode has been deployed to derive zonal-, meridional- and vertical-wind components instead of using continuous scanning observation-mode in the Doppler lidar observations. TKE has been estimated by the three wind components. Obtained formulation between w and TKE in this study turned out to be smaller than the one based on the cloud resolving model simulations for a given TKE (Fletcher and Bretherton 2009). Possible implication of the findings for modeling studies as well as space-borne active sensor analyses is also discussed.
In this study, we have conducted measurements of vertical- and horizontal-wind velocity and cloud base height by the synergetic observation system. Synergetic observation system includes 2µm-coherent Doppler lidar with scanning function, 355-nm Multiple-Field-of-View Multiple scattering polarization lidar (355nm-MFMSPL), 355nm-High-spectral-resolution-lidar (355nm-HSRL) and 94GHz Doppler cloud radar (HG-Spider). We first developed the cloud mask schemes that can be applied to the 2µm-coherent Doppler lidar by using vertical structure of SNR. Then the mask scheme has been evaluated by using the cloud detection results by the 355nm-MFMSPL. Analyses showed that general agreement in cloud mask results between the two lidars has been achieved. Then vertical velocity (w) at cloud bottom height has been analyzed in relation to the estimated turbulence kinetic energy below cloud bottom (TKE). Five-beam-observation-mode has been deployed to derive zonal-, meridional- and vertical-wind components instead of using continuous scanning observation-mode in the Doppler lidar observations. TKE has been estimated by the three wind components. Obtained formulation between w and TKE in this study turned out to be smaller than the one based on the cloud resolving model simulations for a given TKE (Fletcher and Bretherton 2009). Possible implication of the findings for modeling studies as well as space-borne active sensor analyses is also discussed.