Table of Contents

• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Data Files
• Parameters
• Instruments
• Deployments
• Project Information
• Program Information
• Funding

Since 1977, the Northeast Fisheries Science Center has been collecting hydrographic data on the northeast US continental shelf in support of efforts to understand how the components of this ecosystem influence the distribution, abundance, and productivity of living marine resources. Temperature and salinity profile data are collected on all Northeast Fisheries Science Center cruises, amounting to nearly 2000 profiles collected each year on the northeast continental shelf from Cape Hatteras to the Gulf of Maine. The data are collected aboard a variety of vessels, but most regularly from the Delaware II, HB Bigelow. The data are used to characterize baseline conditions on the shelf, as documented in annual summaries of regional average temperature and salinity, surface and bottom property distributions and their anomalies relative to a consistent reference (http://www.nefsc.noaa.gov/HydroAtlas.) The data have been and continue to be used to monitor the seasonal to inter-annual variability of water properties on the northeast US continental shelf.

These data are also accessible directly from the National Marine Fisheries Center http://www.nefsc.noaa.gov/epd/ocean/MainPage/ioos.html and from the National Oceanographic Data Center at http://www.nodc.noaa.gov/. Some of the data are also available from the Canadian Marine Environmental Data Service (MEDS) at http://www.meds-sdmm.dfo-mpo.gc.ca/isdm-gdsi/index-eng.html .

The null values of '999' were replaced with 'nd'.

A unique purpose code has been assigned to each survey, identifying the Northeast Fisheries Science Center program or larger national program to which those data are associated.

Purpose Codes:                     
01 BLUEFISH SURVEY                                         
02 LOBSTER SURVEY                                           
03 COD SPAWNING SURVEY                                     
04 COOPERATIVE RESEARCH SURVEY - GOOSEFISH                  
05 COOPERATIVE RESEARCH SURVEY - IBS COD                   
06 COOPERATIVE RESEARCH SURVEY - IBS YELLOWTAIL            
07 COOPERATIVE RESEARCH SURVEY - GEAR SELECTIVITY STUDY    
10 NMFS NEFSC BOTTOM TRAWL SURVEY                          
11 MASSACHUSETTS DMF BOTTOM TRAWL SURVEY                    
12 NMFS NEFSC HERRING BOTTOM TRAWL SURVEY                   
13 NMFS NEFSC MISCELLANEOUS BOTTOM TRAWL SURVEY             
14 BIOME STATIONS                                           
15 SCOTIAN SHELF REVISION                                   
16 NMFS ACOUSTICS SURVEY  
17 DEEPWATER SYSTEMATICS                                    
19 EXPERIMENTAL GEAR TEST                                  
20 GLOBEC BROADSCALE SURVEY                                
21 GLOBEC PROCESS STUDY                                     
22 ECOSYSTEM MONITORING                                     
23 MARMAP                                                   
24 LARVAL HERRING SURVEY                                    
25 12-MILE DUMPSITE                                         
26 ICNAF LARVAL HERRING SURVEY                              
27 WARM CORE RING CRUISE                                    
28 COLTON CRUISE                                            
29 STVOR CRUISE                                           
30 FOREIGN BOTTOM TRAWL SURVEY                              
31 FOREIGN PELAGIC TRAWL SURVEY                            
32 FOREIGN MACKEREL SURVEY                                  
33 FOREIGN FEEDING ECOLOGY                                 
35 MISCELLANEOUS FOREIGN SURVEY                            
36 FOREIGN HERRING BOTTOM TRAWL SURVEY                     
37 FOREIGN SCALLOP SURVEY                                   
38 FOREIGN GEAR CRUISE                                      
40 NMFS NEFSC SHRIMP SURVEY                                 
50 NMFS NEFSC CLAM AND QUAHOG SURVEY                       
60 NMFS NEFSC SEA SCALLOP SURVEY                            
70 NMFS NEFSC GEAR COMPARISON                               
71 NMFS GEAR/SENSOR TESTING AND MENSURATION                 
80 FOOD CHAIN DYNAMICS FEEDING ECOLOGY SURVEY
81 COASTAL OCEAN PROGRAM  
82 APEX PREDATOR SURVEY          
90 MISCELLANEOUS NON-RANDOM RESOURCE INVESTIGATION CRUISE   
91 BENTHIC HABITAT STUDY                       
93 MARINE MAMMAL SURVEY

Occasionally, a cruise identifier (or opsid) contains more than one part. For example, ALB0301, actually consists of five (5) opsid's. This is because multiple hardware breakdowns during the cruise required that the ship return to port. Because these port visits spanned many days, different opsid's were assigned to each contiguous leg of the cruise.

The temperature/salinity profile data provided here were collected using Niskin Bottles, Expendable Bathythermographs (XBT used in the 1970s and 1980s), Neil Brown Instrument systems MK3 and MK5 CTD units, and SeaBird Electronics SBE19 and SBE19+ SEACAT profilers and SBE 9/11 CTD units. On NEFSC surveys, CTD data are typically deployed in one of two modes: (1) during a bongo net tow, the CTD instrument is mounted on the conducting wire above the bongo frame and data are collected as a double oblique profile with the ship steaming at ~2 kts, (2) during a non-net tow, the CTD is mounted vertically on the wire and the sensors are soaked for one minute at the surface prior to descent. Because the sensors are not soaked at the surface prior to descent during bongo tows, the upper 30 meters or more of the downcast is unreliable. For this reason, the up-cast profile data has been processed as the primary data.

During the 1970's and 1980's, the Expendable Bathythermograph (XBT) was used to collect the data.

All raw CTD profile data were processed using the Seabird manufactured software: DATCNV, FILTER, ALIGNCTD, BINAVG, DERIVE, and ASCIIOUT to produce 1 db averaged ASCII files. The CTD data provided should be considered high quality. The data have been calibrated with in situ water samples and have been subjected to rigorous quality control procedures. Following each cruise, water samples collected during vertical casts were analyzed using a Guildline AutoSal laboratory salinometer to provide quality control of the CTD salinity data. Vertical density profiles are examined for inversions due to bad conductivity or temperature readings and/or sensor misalignment. Egregious cases are replaced with a flag value of 999.

Processing was done by Maureen Taylor, Red Wright, David Mountain, and James Manning.

On September 21, 2010, edits were made to the file supplied to BCO-DMO to replace all occurrences of the missing value "999" with the missing value of "nd". Also, three character ship abbreviations were replaced with two character abbreviations to match those used in the EcoMon Zooplankton datasets.

Please note that some of the parameter names have been changed (or added)0 from those provided by the data contributor in order to facilitate data interoperability and data reuse. For example, the parameter gmt_yday1 was changed to yrday_gmt and month, day, and time parameters were added, based on the values of yrday_gmt.