Ground-Based Doppler Lidars Observing Urban Boundary Layer Flows

Multiple Doppler Lidars were deployed in the NY/NJ metropolitan area to observe the complex urban boundary flows in order to study the atmospheric effects due to the Urban Canopy. Different scan strategies for the Doppler Lidars were implemented to provide an understanding of the processes that impact the circulations within the Urban Canopy Layer and above and throughout the Planetary Boundary Layer (PBL). Range Height Indicator (RHI) and Doppler Beam Swinging (DBS) scans were implemented. The analysis of the Doppler Lidar return signals using the volume velocity processing (VVP) retrieval technique, paired with forward dynamical models, allows both inverse and forward modeling techniques to be implemented that can bring insight to the complexity of turbulent flows. This will advance previous observational studies focused on urban coastal regions by focusing on the forces that are caused by the thermodynamic and geographic effects that occur during heat events. The observations allows for mean flows to be distinguished from complex flows for a better understanding of the transport of air masses that can be provided to analyze the accuracy of high resolution numerical weather prediction models that are being developed to interpret and model turbulence during such events. Other ground based remote sensing and in-situ observations were collected to support the overall perspective of the ground and upper level pollutant transport in urban coastal areas, particularly during heat wave events. These observations are relevant to stakeholders that are concerned about the regulation of the transport of pollutants in and around densely populated urban areas. It is found that the eddies that form in such highly populated urban areas sometimes are effected by the land/air/water interactions that cause these air flows.