OPC_seasoar

 PI:              Mark Huntley and Meng Zhou
 of:              Scripps Institution of Oceanography (Huntley) and
                  University of Minnesota, Duluth (Zhou)
 dataset:         Optical Plankton Counter data - SEASOAR Tows
 project/cruise:  AESOPS/KIWI06 - APFZ Survey Cruise 1
 ship:            Roger Revelle

 Sampling Methodology

 Parameter       Description                                       Units

 event           event number from event log
 sta             station number from event log
 depth_begin     starting depth of the integrated interval         meter
 depth_end       ending depth of the integrated interval           meter
 lat_n           nominal latitude of the integrated interval       decimal degrees
 lon_n           nominal longitude of the integrated interval      decimal degrees
 vol_filt        water volume filtered                             m^3
 counts_tot      total counts collected within the integrated
                  interval normalized by the water volume
                  filtered
 ESD_XX          Equivalent Spherical Diameter size class
                  number from 1 to 40 (see ESD note)