3.7 Bottom-Mounted Instrumentation Array (DAISY) 



3.7.1 Water Temperature 



During the day preceding the passage of Hurricane Gloria, 

 near-bottom water temperatures at the deployment point (New London 

 Disposal Site, NLON) ranged from a low of approximately 20.4°C to 

 a maximum of 21.2°C (Figure 3-87). Storm passage at 1445 EDST on 

 27 September suppressed the temperature range and essentially 

 eliminated any evident tidal signature. The effects of this 

 perturbation persisted for nearly 48 hours. Temperatures during 

 the initial 24 hr period after passage of the storm varied by less 

 than 0.2°C and were weakly correlated with tidal phase. After 1500 

 EDST on 28 September, the temperature range increased slightly and 

 tidal correlations progressively improved. By 0600 EDST on 29 

 September, pre-storm conditions were re-established and the 

 decrease in water temperature approximated that observed during 

 the period prior to the storm (Figure 3-87) . Over the remainder 

 of the deployment period, water temperatures closely followed tidal 

 phase with average values slowly decreasing in response to the 

 coincident decrease in local air temperature (Table 3-5) . 



3.7.2 Salinity 



Near-bottom salinity displayed a response to the passage 

 of Hurricane Gloria similar to that observed within the water 

 temperature records. Prior to the storm, salinities varied in 

 response to the local tidal phase with values ranging from a low 

 of approximately 30.8 ppt to a high of 31.6 ppt (Figure 3-88). 

 Following storm passage, tidal variability was evidently suppressed 

 for a period of approximately 48 hrs and the average salinity 

 slowly decreased in response to increasing freshwater inputs from 

 the Thames River and adjacent streams. The majority of this 

 increased streamflow was the result of the passage of tropical 

 storm Henry earlier in the week and some the direct effect of 

 Gloria. Within southeastern Connecticut, this latter component was 

 expected to be relatively small due to the virtual absence of 

 significant rainfall during Gloria. Reviews of U.S. Geological 

 Survey streamflow data, however, indicate that, over the period 

 26-27 September, discharge from the Thames River increased from 

 approximately 570 cfs to nearly 1000 cfs. Discharge continued to 

 progressively increase over the next three days and, by 1 October, 

 peaked at approximately 2 000 cfs. Over the next three days, values 

 decreased progressively, falling to approximately 1600 cfs, and 

 then remained essentially constant over the remainder of the 

 deployment period. The long term response of near-bottom 

 salinities to this streamflow cycle was evident in the array 

 observations which showed a progressive decrease in average 

 salinity from 2 6 September to 1 October and a slight increase 

 thereafter (Figure 3-88) . 



26 



