Figure 2. Temporal variations of (a) organic carbon (OC), (b) water-soluble organic carbon (WSOC), (c–f) fluorescence intensities, as well as (g–l) molecular marker compounds⁵,⁸ in the aerosol samples collected at Alert in the Canadian High Arctic.

Levoglucosan is a tracer for biomass-burning emissions³; PAHs are anthropogenic tracers for fossil fuel combustion; arabitol and mannitol are tracers for atmospheric fungal spores⁴⁰; sucrose is a tracer for primary bioaerosols such as pollen⁴¹; 2-methyltetrols and pinic acid are tracers for secondary organic aerosols from the photooxidation of isoprene and monoterpenes⁷,⁹, respectively.