Table I.

Time lags between various time series using the multi-taper cross-spectral density method (Thomson, 1982)

	T = 23°C			T = 28°C
	h−1		h	h−1		h
	0.12	0.92***	0.78	0.14	0.98***	0.53
	0.11	0.94***	0.20	0.14	0.95***	0.26
	0.11	0.90***	2.86	0.14	0.98***	2.08
	0.22	0.58*	0.75	0.29	0.71**	−0.23
	n/a	n/a	n/a	0.29	0.69*	−0.32

Significance level is the two-tailed probability that Coh (i.e. the square-root of Coh², here treated as a correlation coefficient) does not differ significantly from zero, as compared against the Student's t distribution (critical values of Coh², df = 6, are 0.50 for P < 0.05*, 0.70 for P < 0.01**, and 0.82 for P < 0.001***). Mean Coh² and time lag () data are shown for the mean frequencies () over which their corresponding CSD is of relatively high strength. By convention, the CSD of two signals, A and B, i.e. CSD〈A,B〉, at a given frequency will have a positive value of δ if A leads B.