Laser based observations of key inorganics (LOKI) on-board the UK research aircraft

The UK research aircraft is being equipped with flux capable measurements of NO, NO2, SO2 and O3 in the Laser based Observation of Key Inorganics (LOKI) instrument rack. All instruments within the rack are being made in-house.This presentation will discuss the aspects of the new instrumentation as well as the sample inlets used that allow high time resolution (10 Hz), high precision measurements to be made over the working envelope of the aircraft.The need for this improvement in the gas sensing capabilities on board is driven by a number of factors: the increasing desire to use flux measurements to calculate emission rates and identify sources, smaller changes in concentration being of interest (SO2 depletion in clouds) as well as reductions in absolute ambient concentrations of some of these species below the detection limits of currently deployed instrumentation.Laser Induced Fluorescence is used for NO (Rollins et al., 2020), NO2 (converted to NO), SO2 (Rollins et al., 2016), with O3 being monitored using Broadband Cavity Enhanced Absorption Spectroscopy (BBCEAS) (Hannun et al., 2020).