primprod_ondeck

 PI:              Richard Barber, Duke University, rbarber@duke.edu
                  John Marra, Lamont Doherty Earth Observatory, marra@ldeo.columbia.edu
                  Walker Smith, Virginia Institute of Marine Science, wos@VIMS.EDU
 dataset:         Primary Production, incubated on deck, 24 hours
 technician:      Michael Hiscock, Duke University, hiscock@duke.edu
 project/cruise:  AESOPS/RR_KIWI_09; APFZ Process Cruise 2
 ship:            R/V Roger Revelle
 
 Methodology: 
   - Chapter 19 of the JGOFS protocols (1994) "Primary Production by 14C"
   - Hiscock, M.R., Marra, J., Smith, W.O., Jr., Goericke, R., Measures, 
     C.I., Vink, S., Olson, R.J., Sosik, H.M., Barber, R.T., in press. Primary 
     Productivity and its Regulation in the Pacific Sector of the Southern
     Ocean. Deep Sea Research II.
   - Barber, Richard T. 1993. In Situ Primary Production Protocols.
     U.S. JGOFS Equatorial Pacific Protocols, 1993, section 7.
   - Smith, W. O., Jr., R. T. Barber, M. R. Hiscock and J. Marra (submitted)
     The Seasonal Cycle of Phytoplankton Biomass and Primary Productivity
     in the Ross Sea, Antarctica.   Deep-Sea Research II.
   - Barber, R. T., L. Borden, Z. Johnson, J. Marra, C. Knudsen, and C.C.Trees
     (1997) Ground truthing modeled kpar and on deck primary productivity
     incubations with in situ observations. SPIE 2963, 834-839.
   - Barber, R. T. and F. P. Chavez (1991) Regulation of primary productivity
     rate in the equatorial Pacific Ocean.  Limnol. Oceanogr. 36, 1803-1815.
   - Morel, A. (1988) Optical modelling of the upper ocean in relation to its
     biogenous matter content (Case 1 waters).  
     Journal of Biophysical Research 93, 10749-10768.


 Parameter         Description                                     Units

 event             event number, from event log
 sta               station number, from event log
 cast              cast number, from event log 
 cast_type         TM = trace metal rosette
                   CTD = CTD rosette
 bot               Goflo or Niskin bottle number
 depth_n           nominal depth sampled by Goflo or Niskin        meters
 chl_a             chlorophyll_a as measured by HPLC method        mg Chl m-3
                     In cases where we had primary productivity 
                     measurements but no HPLC values, the 
                     fluorometric chlorophyll a values were 
                     corrected to photosynthetically-active HPLC 
                     chlorophyll a values according to a linear 
                     regression analysis of pairs of HPLC and 
                     fluorometric measurements made from the 
                     same water bottles (m=0.401, b=-0.000913, 
                     n=106, r2 = 0.69) (Hiscock et al., in press)
 light             incident light the incubator receives           percent 
 depth_inc         effective depth of the samples incubated        meters
                     on deck (based on Morel optical model)
                     Note:  Analysis of on deck estimates of
                     primary productivity in the equatorial
                     Pacific made from a variety of ships in the
                     1980's showed that the process of determining
                     kpar and assigning a depth to each percent
                     light level was the largest source of
                     variation in estimating primary productivity
                     (Barber and Chavez, 1991).  To eliminate
                     individual, ship and cruise dependent sources
                     of variability in the estimation of kpar and
                     assignment of light depths Andre Morel's
                     optical model was employed (Morel, 1988;
                     Barber et. al., 1997).  The model estimates
                     the profile of light extinction based on a
                     profile of extracted fluorometrically-
                     determined chlorophyll a concentrations.  
                     The Morel light profile is also helpful in 
                     comparing on deck vs. in situ primary 
                     production integrations.
 pp24              primary production, carbon assimilation         mmol C m-3 d-1
                     (24 hours)
                     Note:  On deck primary productivity
                     incubations were ground truthed with
                     in situ incubations (Barber et. al., 1997).
 pb24              carbon assimilation per unit chl_a (24 hours)   mmol C mg Chl-1 d-1
 depth_light_1     depth of 1% light level based on Morel          meters
                     optical model 
 pp24_int_1        primary production, carbon assimilation         mmol C m-2 d-1
                     (24 hours) integrated from 0 meters to the
                     depth of the 1% light level based on Morel
                     optical model (depth_1%)
                     Note: 1% light level productivity was
                     extrapolated from the on deck productivity
                     profile and calibrated with in situ ground
                     truthing.
 depth_light_0d1   depth of 0.1% light level based on Morel        meters
                     optical model
 pp24_int_0d1      primary production, carbon assimilation         mmol C m-2 d-1
                     (24 hours) integrated from 0 meters to the
                     depth of the 0.1% light level based on Morel
                     optical model (depth_0.1%)
                     Note: 1% and 0.1% light level productivity
                     values were extrapolated from the on deck
                     productivity profile and calibrated with
                     in situ ground truthing.
 pp24_opt          optimum primary production for profile,         mmol C m-3 d-1
                     carbon assimilation (24 hours)
 pb24_opt          optimum carbon assimilation per unit            mmol C mg Chl-1 d-1
                     chl_a for profile (24 hours)