Description
The Fast-J model calculates photolysis rates (J-Values, e.g., for reactions that involve O3, NO2, etc.) in an atmosphere with an arbitrary number of aerosol layers. These aerosol light interactions can change the local photochemistry in the planetary boundary layer. Understanding photochemical changes at the surface is critical for accurate air quality forecasting. Fast-J calculations with pre-determined aerosol layer heights have resulted in differing J-Values at the surface by as much as 50%. To further explore the effects of aerosol layer heights on J-Values, we turn to NASA's AerosolCloud meTeorology Interactions oVer the western ATlantic Experiment (ACTIVATE). From ACTIVATE, aerosol layer heights are calculated using the NASA High Spectral Resolution Lidar 2 (HSRL-2) and Research Scanning Polarimeter (RSP). Aerosol heights calculated from HSRL-2 and RSP are used as inputs to Fast-J to quantify the sensitivity of J-Values to aerosol layer height. This work is part of an effort to create a J-Value product for the upcoming NASA PolCube mission. PolCube is a CubeSat hosting a polarimeter instrument with the goal of retrieving detailed aerosol dust properties over the ocean. The absence of a co-located lidar on PolCube complicates validation of aerosol layer height retrievals. ACTIVATE provides coincident lidar and polarimeter measurements, making it ideal to investigate how uncertainties in polarimetric aerosol layer height retrievals affect J-Values. Insights from this analysis will guide the development of a PolCube aerosol layer height and tropospheric J-Value product, as part of my work funded by the Virginia Space Grant Consortium graduate research fellowship.