James Bishop
Lawrence Berkeley Laboratory

Notes on POC measurements from MULVFS samples

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depth       depth in meters

temp        in-situ temperature recorded by Applied Microsystems STD-12 
            data logger. Interpolated to the depth of sampling. Temp good to 
            0.02 C.

wt_dry_l    >53 um particulate dry weight ... measured gravimetrically
            corrected for seasalt using Na analysis and corrected using 
            in-situ blanks. 
            wtseasalt = Na*3.25
            wt_dry_l = wtfilterfinal - wtseasalt - wtfilterinitial 
                        - blank_adjustment.

poc_s       is particulate organic carbon measured by CHN analyzer after
            samples had been treated by fuming HCl to remove carbonate.
            poc_s is the sum of carbon measured in both 1-53 um and
            <1um size fractions sampled by MULVFS. See protocols
            on web page for description of MULVFS size fractions.
            Concentrations are in nmol/L. 

poc_l       is >53 um particulate organic carbon estimated gravimetrically.
            There are two classes of numbers in this column:

            (1) Numbers with significant digits past the decimal point were 
            gravimetrically estimated poc:
 
              wtpom = wt_dry_l - wtcaco3 - wt opal (all concentrations in ug/L). 
              poc_l = wtpom/30
      
            (2) Numbers that are integers are: INTERPOLATED values due to the 
            fact that MULVFS 53 um filters at this depth were subsampled 
            at sea. Interpolation was made from neighboring poc_l values and
            from blue optical density values (see mulvfs object).