Oxygen Depletion and Associated Benthic Mortalities 

 in New York Bight, 1976 



Chapter 7. Water Movement on the New Jersey 



Shelf, 1975 and 1976 



D. A. Mover, D. V. Hansen, and S. M. Minton^ 



CONTENTS 



Page 



149 Introduction 



149 Data Processing 



151 Time Scales 



152 Temporal Variation of Currents 

 157 Regional Variation of Currents 

 157 Upwelling 



157 Local Meteorological Effects 



162 Summary 



162 Acknowledgments 



162 References 



' Atlantic Oceanographic and Meteorological Labo- 

 ratories, Environmental Research Laboratories, NOAA, 

 Miami, FL 33149 



INTRODUCTION 



Current meter moorings were maintained at several 

 sites in the New York Bight during the late winter and 

 spring of 1975 and from autumn 1975 throughout 1976. 

 The strength and variation on various time scales of cur- 

 rents observed on the continental shelf off New Jersey and 

 Long Island, N.Y., were investigated to determine the 

 differences between the 2 years. These differences may 

 help explain why anoxic conditions developed in New Jer- 

 sey near-bottom waters during summer 1976, but did not 

 develop in summer 1975. 



Seven taut-wire moorings (with Aanderaa current me- 

 ters and tethered surface spar buoys) were selected for 

 analysis from those deployed during the 1975 and 1976 

 MESA current surveys (fig. 7-1, table 7-1). On the New 

 Jersey shelf, three stations (Pll, 49, and LT2) were es- 

 tablished in shallow water (about 30 m), and two (P12 

 and LT3) were in deeper water (60-70 m) near the shelf 

 break. Off Long Island, two stations (P31 and LT4) were 

 established near shore in 49 m of water. Because low 

 dissolved oxygen (D.O.) concentrations were observed 

 near the bottom, this analysis focuses on near-bottom 

 motions. Weather data also were obtained from John F. 

 Kennedy International Airport (JFK) and from two me- 

 teorological data buoys, EB34 and EB41 (fig. 7-1). 



DATA PROCESSING 



Only the highest quality data were retained for analysis. 

 Raw current-meter data (sampling intervals were mostly 

 30 minutes, some were 20-minute intervals) were scru- 

 pulously edited. These were then 3-hour low-pass filtered 

 and resampled hourly, resulting in a more manageable 



149 



