delta_N_C_underway

 PI:              Mark Altabet and Roger Francois
 of:              University of Massachusetts, Dartmouth (Altabet)
                  Woods Hole Oceanographic Institution (Francois)
 dataset:         Natural nitrogen and carbon stable isotopic composition; underway data
 project/cruise:  AESOPS/NBP96-4A - Process Cruise 1
 ship:            R/V Nathaniel B. Palmer


 Methodology:
 Methods for nitrate isotopic composition reported in:
     Sigman, D. M., M. A. Altabet, R. Michener, D. C. McCorkle, B. Fry and R. M.
     Holmes. (1997). Natural Abundance-level measurement of the nitrogen isotopic
     composition of oceanic nitrate: an adaptation of the ammonia diffusion
     method. Mar. Chem. 57, 227-242.

 Methods for POM isotopic composition in:
     Altabet, M. A., and R. Francois, 1994.  Sedimentary N isotopic ratio as a
     recorder for surface ocean nitrate utilization.  Global Biogeochemical
     Cycles., 8, 103-116.


  Parameter    Description                                        Units

  date         date (YYYYMMDD) decoded as follows                 YYYYMMDD
                  YYYY = year of decade, MM = month,
                  DD = day
  time         time of day (hhmm) decoded as follows              HHMM
                  hh = hour, mm = minutes
  lat          latitude, negative=south                           decimal degrees
  lon          longitude, negative=west                           decimal degrees
  dN15_NO3     delta 15N of dissolved nitrate relative            per mil (ppt)
                  to atmospheric N2
  dN15_POM     delta 15N of particulate organic matter relative   per mil (ppt)
                  to atmospheric N2
  dC13_POM     delta 13C of particulate organic matter relative   per mil (ppt)
                  to the PDB standard