Fig. 1.

Schematic diagram of bilinear factor analysis of a mass spectral matrix of an organic aerosol (ORG). The time series of the factors (ts _n) make up the matrix TS (Eq. 3) and the mass spectra of the factors (ms _n) make up the matrix MS (Eq. 4). The differences between the measurements and the modeled results are represented as the residual matrix E. (Adapted from Ref. [38]). An example of the factor results obtained from PMF analysis of an ambient AMS dataset is shown in Fig. 2