primprod_ondeck
PI: Richard Barber, Duke University
John Marra, Lamont Doherty Earth Observatory
Walker Smith, Virginia Institute of Marine Science
dataset: Primary Production, incubated on deck, 24 hours
technician: Michael Hiscock, Duke University
project/cruise: AESOPS/RR_KIWI09; Process Cruise 2
ship: R.V. Roger Revelle
Methods reported in:
- Please see Chapter 19 of the JGOFS protocols (1994) "Primary Production by 14C"
- Barber, Richard T. 1993. In Situ Primary Production Protocols.
U.S. Joint Global Ocean Flux Study - 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 fluorometric mg Chl m-3
method
chl_a_int_depth depth to which chl_a is integrated meters
chl_a_int integrated from 0 meters to the depth of mg Chl m-2
the deepest sample bottle of the euphotic
profile (chl_a_int_depth)
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 chlorophyll
concentrations. The Morel light profile
is then used to assign effective incubation
depths used for integration of water column
productivity.
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_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_0.1 depth of 0.1% light level based on Morel meters
optical model
pp24_int_0.1 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)