FREQUENCY RESPONSE OF A MARINE ECOSYSTEM 



31 



1000 



500 - 



(a) 



3000 



1 



24 26 



4 8 12 16 



FREQUENCY, cycles/year 



(d) 



Fig. 5 Variance spectra for four Narragansett Bay time series. Each 

 spectral estimate smoothed over seven adjacent frequency bands, (a) 

 Solar radiation (1959—1975), B = 0.325 cycles/year, (b) Surface 

 water temperature (1959—1975), B = 0.325 cycles/year, (c) Surface 

 ammonia concentration (1972—1975), B = 1.31 cycles/year, (d) 

 Phytoplankton cell abundance (1960—1974), with 95% confidence 

 interval; B = 0.325 cycles/year. 



