Filename =  PSD_Coulter_MALINA_Reynolds.xls
Version: 01 April 2011

MALINA cruise Leg 2B, AMD0908
CCGS Amundsen, 30 July - 27 August 2009

PIs:  Rick Reynolds (rreynolds@ucsd.edu) and Dariusz Stramski (dstramski@ucsd.edu)
      Marine Physical Laboratory
      Scripps Institution of Oceanography, UCSD
      La Jolla, CA 92093-0238

This document provides a synopsis of methodology for Coulter Counter particle size 
measurements performed on Leg 2B of the MALINA cruise.

DATA FORMAT AND STATION NAMES:
The data are provided as a single MS Excel spreadsheet containing the Particle Size 
Distribution (PSD) for each discrete water sample measured on the cruise.  

SIO station names and event numbers represent internal Scripps names.  The official 
cruise station name is also provided (StationAlias).  The nominal sampling depth 
from the CTD is given for each sample, with 0 used to represent the surface CTD bottle.

METHODOLOGY:
The particle size distribution of discrete water samples collected with the CTD/Rosette 
was measured using a Coulter Counter Multisizer III (Beckman-Coulter).  Filtered 
seawater (0.22 um) was used as the diluent and blank.  For most samples, measurements 
were made using two different aperture sizes;  a 200 um aperture (measurement 
range 4 - 120 um) and a 30 um aperture (range 0.6 - 18 um).  

Water samples were generally collected from the "IOPs" CTD/Rosette cast.  Two water 
depths were typically sampled; the surface and the depth of the fluorescence maximum.  
For each sample, 20-25 replicate measurements were usually made for each aperture and 
the individual runs summed to yield the final result.  Total volumes of water analyzed 
were approximately 350 ml for the 200 um aperture and 8 ml for 30 um aperture.

Following baseline correction, data from both apertures were merged into a single 
size distribution consisting of 394 discrete size bins (reported as equivalent spherical 
diameter in micrometers) and particle concentration (Number of particles per ml) 
within each bin.  The center value and lower and upper limits of each size bin are provided.  
The value of -999 is used to indicate no data.

REFERENCES:
Reynolds, R.A., D. Stramski, V.M. Wright, and S.B. Wozniak.  Measurements and characterization
 of particle size distributions in coastal waters.  Journal of Geophysical Research, 115, C08024, 
doi: 10.1029/2009JC005930.  (2010).