TABLE 5.

Correlations of INP factors with physical and chemical measurements of the precipitation, shown as Pearson correlation coefficients calculated between factors of EFA and measured variables of precipitation^a

INP factor	Cell abundance (DNA-containing cells liter−1 precipitation)	pH	Conductivity (μS cm−1)	Concn (μM) of:				DOC (ppm)	Fluorescent organic intensity (RU) by componentb:
				Cl−	Na+	NO3−	SO42−		C1	C2	C3
total−5 to −11	0.45*	0.39*	0.26	−0.41*	−0.34	−0.03	0.29	−0.01	0.48*	0.23	−0.01
total−11 to −14	0.25	0.19	0.23	0.07	0.07	0.17	0.23	−0.002	0.27	−0.01	−0.08
bio−5 to −10	0.43*	0.35	0.20	−0.35	−0.31	−0.08	0.30	−0.01	0.47*	0.14	−0.07
bio−13 to −14	0.06	−00.1	0.27	0.25	0.34	0.26	0.30	0.24	0.30	0.01	0.03
bio−11 to −12	0.29	0.25	0.22	−0.20	−0.21	0.18	0.21	0.14	0.39*	0.40*	0.15
bac−5 to −10	0.54**	0.29	0.17	−0.37	−0.42*	−0.18	0.20	−0.07	0.46*	0.20	−0.08

^aSignificance levels of Pearson correlation coefficients are as follows: *, P < 0.05; **, P < 0.01; ***, P < 0.001. The number of samples of each were the following: cell abundance, n = 61; pH and conductivity, n = 52; ionic concentrations, n = 31; DOC and C1 to C3, n = 43.

^bRU, Raman units.