Analysis of multi-year fine mode aerosol remote sensing retrievals and microphysical measurements at a high-Arctic site

Aerosol remote sensing (RS) from satellite- and ground-based platforms was revolutionized over the past 25 years by the measurements of the NASA-led (i) “A-train” mission and (ii) the AERONET network of sunphotometer / sky radiometers as well as (iii) the proliferation of near-automated ground-based vertical-profiling lidars. These platforms enable the measurement of key parameters such as the aerosol optical depth (AOD) and aerosol extinction coefficient profiles.

Analyses of high-Arctic satellite measurements are relatively rare because, even though the A-train had a much greater overpass frequency relative to mid-latitudes, there are few ground-stations that are equipped to validate / evaluate the satellite measurements. The analysis of the ground-based RS and microphysical data is only now coming into its own as the diverse types of ground- and satellite-based aerosol and simulation data are intercompared.

Surface-based, passive and active RS retrievals as well as volumetric sampling measurements of intensive and extensive aerosol properties have been carried out for more than a decade at the high-Arctic PEARL (Polar Environment Atmospheric Research Lab) sites of 0PAL and Ridge lab at Eureka, Nunavut, Canada. Comparisons of the AERONET fine mode (FM) AOD vs (Ridge lab) FM (sub-m) particle-volume concentrations (“FM vol” measured using a Scanning Mobility Particle Sizer) for a variety of aerosol events (notably smoke at different altitudes, Arctic haze and Asian pollution) will be presented for the first time. The analysis will also incorporate comparisons with 0PAL lidar profiles, A-train colour imagery and derived FM AOD imagery.

The results, showing varying degrees of FM AOD vs FM vol correlation over different aerosol events, were analyzed to determine the aerosol species, event source(s), plume height, etc. The FM AOD and FM vol (species-dependent) predictions of the NAAPS-RA (NRL aerosol re-analysis) model and its vertical profile simulations were employed to contextualize the passive and active measurements.