Tools

All data files in this archive are provided in netCDF format. For your convenience, read files in C, with an accompanying Makefile (see below), are included. There are also many software packages freely available or licensed with utilities to access the data in netCDF-formatted files. You can find a comprehensive list of these software packages at http://www.unidata.ucar.edu/software/netcdf/software.html


read_ac9cal.c
read_es3aop.c
read_hydro_bottle.c
read_jes2_j1r1.c
read_jes3_R1L1.c
read_rad.c

Makefile



Data File Descriptions

The jes2_hydro_bottle.cdf and jes3_hydro_bottle.cdf files contain bottle data from the CTD/rosette casts. The temperature, salinity, chlorophyll fluorescence, and beam transmissometer data are from the in situ sensors. Dissolved oxygen, chlorophyll, and nutrient data are from batch samples. The corrected salinity data are based on the regression between the rosette CTD and the batch salinity samples that were measured on a Guildline Autosal conductivity bridge. Extracted chlorophyll was measured fluorometrically using a Turner Designs 10-005 fluorometer. The variable "nitrate_kwangju" is from nutrient analysis provided by Sung Yang, Kwangju University, Kwangju, Korea.

The bottle data files can be read with read_hydro_bottle.c

The Seasoar data are found in the following files:
  • jes2_seasoar_j1r1.cdf
  • jes3_seasoar_R1L1.cdf
  • jes3_seasoar_rad2.cdf
  • jes3_seasoar_rad3.cdf
  • jes3_seasoar_rad4.cdf
The data in jes2_seasoar_j1r1.cdf and jes3_seasoar_R1L1.cdf include Seasoar CTD, fluorometer, transmissometer and PAR sensor data. jes3_seasor_R1L1.cdf also contains the AC9 data as well. It was calibrated by:
  1. correcting with a wet calibration
  2. correcting for temperature and salinity effects
  3. adjusted for scattering — this is a tenuous adjustment as the absorption at 715 nm appeared to be anomalously low, and there was some variability in the minimum absorption at 715 nm.
The data in the jes3_seasoar_rad*.cdf files contain calibrated chlorophyll measurements. Chlorophyll was calibrated by comparing ranges of chlorophyll concentration from the CTD/rosette where the bottle chlorophyll samples were taken, with the range and concentration distribution for the Seasoar fluorometer. The fluorometer was not working during the first radiator, but was available for the other three radiators across the Subpolar front.

jes2_seasoar_j1r1.cdf can be read with read_jes2_j1r1.c
jes3_seasoar_R1L1.cdf can be read with read_jes3_R1L1.c
jes3_seasoar_rad*.cdf can be read with read_rad.c

Apparent optical properties from radiometer profiles on the bio-optical profiling system are available in the es3aopxx* files. These data were obtained with a Satlantic profiler using 207i and 207r radiometers for downwelling irradiance (Ed) and upwelling radiance (Lu), respectively. The files include:
  • pro  -  original light profiles
  • bin  -  binned data at 1 meter intervals
  • k  -  diffuse attenuation coefficients (1/m)
  • par  -  profile data represented as an integrated PAR value
  • lambda  -  wavelengths for Ed and Lu
The specific variables:

  • lambdaEu: Wavelengths (nm) of the profiler downwelling irradiance sensor
  • lambdaLu: Wavelengths (nm) of the profiler upwelling radiance sensor
  • pro_Ed: Profiled data of the downwelling irradiance (not averaged or smooth)
    Columns correspond to the wavelengths in lambdaEu
    Units: microW/cm2/nm
  • pro_Lu: Profiled data of the upwelling irradiance (not averaged or smooth)
    Columns correspond to the wavelengths in lambdaLu
    Units: microW/cm2/nm
  • pro_depth: Profiler depths for the data in pro_Ed and pro_Lu
    Units: meters
  • pro_tilt: Profiler package tilt for profile
    Units: degrees
  • bin_Ed: Profiled data of the downwelling irradiance binned to 1 meter intervals
    Units: microW/cm2/nm
  • bin_Lu: Profiled data of the upwelling radiance binned to 1 meter intervals
    Units: microW/cm2/nm
  • bin_depth: Depth bins for bin_Ed and bin_Lu
    Units: meters
  • k_Ed: Diffuse downwelling attenuation coefficient
    Units: m-1
  • k_Lu: Upwelling radiance attenuation coefficents
    Units: m-1
  • k_depth: Depth for attenuation coefficients
  • par: Photosynthetically Available Radiation (PAR)
    Units: quanta/cm2/sec
  • par_pct: PAR as percent [%] of surface PAR
  • kpar: Diffuse attenuation coefficient for PAR
    Units: m-1
  • par_depth: Depth beneath sensor for PAR measurement
The ac9cal* files contain the inherent optical properties, a and c, for the respective stations. These values have been calibrated, but because of breakage and replacement of the reflective flow tube for the absorption side of the Wetlabs AC9, we believe that there is some uncertainty in the values after 1/23/2000, i.e., all the station data available here. Otherwise, AC9 corrections were performed using standard processes including T/S corrections, and the Zaneveld scattering correction. The values of the absorption spectra were adjusted because of an offset caused by the overly low values of a715. The absorption spectra were adjusted based primarily on a555, the typical minimum in the spectra. The stations were corrected in two sets (Set 1: stations 9, 10, and 13 and Set 2: stations 18–24).

A limited set (stations 19–24) of the CTD data on the BOP profiler are available because of malfunctioning telemetry unit. For comparison, the rosette CTD should be used for evaluation of the profiles in the overall oceanographic context. The rosette CTD values (T & S) have been merged into the BOP profile when not available from the BOP CTD. Comparisons between the beam transmissometer on the rosette and the c650 on the AC9 were used for evaluating the overall comparability between the rosette/CTD profiles and the BOP ac9 profiles.

AC9 files:

Variable    (Units)
Latitude    (degrees N)
Longitude     (degrees W)
Depth    (meters)
Temperature–from CTD    (degrees C)
Salinity–from CTD    (psu)
Absorption–412 nm    (meters-1)
Absorption–440 nm    (meters-1)
Absorption–488 nm    (meters-1)
Absorption–510 nm    (meters-1)
Absorption–532 nm    (meters-1)
Absorption–555 nm    (meters-1)
Absorption–650 nm    (meters-1)
Absorption–676 nm    (meters-1)
Absorption–715 nm    (meters-1)
Attenuation–412 nm    (meters-1)
Attenuation–440 nm    (meters-1)
Attenuation–488 nm    (meters-1)
Attenuation–510 nm    (meters-1)
Attenuation–532 nm    (meters-1)
Attenuation–555 nm    (meters-1)
Attenuation–650 nm    (meters-1)
Attenuation–676 nm    (meters-1)
Attenuation–715 nm    (meters-1)

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