Spatial structure of valley winds and aerosols from airborne Doppler lidar data

Doppler lidar has become an important tool for the investigation of the wind and aerosol structure in the lower atmosphere. Airborne Doppler lidars have been deployed in several field studies in recent years and their potential in research and weather forecasting has been demonstrated. In November 2007, several flights were performed with a Twin Otter aircraft over the Salinas valley and adjacent mountains in California. In this talk, wind – and aerosol profiles profiles from the airborne Doppler lidar data are presented. The issues related to extracting wind profiles over complex terrain using airborne Doppler lidar data are discussed and approaches are presented that can potentially improve the retrieval of the wind profiles. We have also performed modeling activities with the goals to evaluate a mesoscale model using the Doppler lidar data and to understand the underlying processes responsible for the observed wind and aerosol structure in the Salinas Valley. We show that the spatially averaged upvalley flows were well simulated, in contrast to some details of the spatial structure. We also provide observational and numerical evidence that the interaction between upslope and upvalley flows resulted in a complex pattern of aerosol transport on the eastern side of the Salinas Valley.