Coarse fraction of tropospheric aerosol at Terranova Bay during the 1890-91 austral summer: Feasibility of a principal component analysis of the multielemental data

Aerosol sampling was performed at Campo Icaro, near the Italian Base at Terranova Bay, in the period between November 1990 and February 1991. The duration of the sampling intervals was 12 hrs and a special aerosol sampler allowed separation of the coarse fraction from the fine fraction (phi(Aer) < 2.3 mu m) Experimental methods and preliminary data of a PIXE multielemental characterization were presented in two previous papers. We present here the results of a statistical Principal Component Analysis (P.C.A.), for coarse fraction samples. P.C.A. turns out to be possible, despite the low level of atmospheric concentrations and the short sampling intervals. Nine elements are used and two P.C.'s are required to explain 99.4% of total variance. With the exception of Fe, two distinct groups of elements contribute separately to each P.C.. Elements S, CI, K, Ca, Fe are strongly correlated with the 1rst P.C., whereas AE, Si, Ti, Mn, Fe are strongly correlated with the 2nd P.C.. Comparison of elemental profiles with geochemical data suggests an interpretation of the two P.C.'s as ''sea salt'' (94.6% of the total variance) and ''crustal''.