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      This website contains the data from Argo floats deployed by the Emerson group at the University of Washington.  The name SOS-Argo stands for “Special Oxygen Sensor Argo Floats” designed and manufactured at the University of Washington.  Each float has an Aanderaa O2 sensor (optode) installed on a 61 cm stalk above the end cap of the float, which allows the float to capture uncontaminated atmospheric pO2 for measurements while the float is at the surface for the purpose of in-situ calibration.   

     The data are listed under the float number indicated on maps of the float location which are presented below.  If the list of float numbers does not appear to the left of this text, it is assessable by clicking on the three horizontal lines in the top left corner of this page.  Not all floats listed are SOS Argo floats.  Those that are different are indicated by asterisks, *.  Float numbers marked with * are standard Argo floats that do not have the oxygen sensor on a tall stalk like SOS Argo floats.  Floats marked with ** are BGC (Biogeochemical Argo Floats, which here means they also have NO3and pH sensors in addition to a pO2 sensor on a 10 cm stalk rather than a 61 cm stalk).

      This web page provides data from 46 SOS Argo floats, 6 standard Argo floats, and 6 BGC Argo floats.  Maps below indicate the locations where each float was deployed.  Right click on the map and choose ‘open image in a new tab’ to zoom in on the map locations.

                             Northwest Pacific

                                 Central and Eastern Pacific

                                     Atlantic

                                         Arabian Sea

                                         Eastern Indian Ocean

          Float data are presented for each float in two ways:  (1) Part I contains a series of figures that summarize float information most pertinent to interpretation of the data in terms of biological oxygen production.  The figures are assessable by clicking on the float number in the list to the left; (2) Part II, contains data files for the float measurements (pressure, temperature, salinity, and pO2 plus NO3, and pH, if available).  The following is a description of the of the data in Parts I and II.

Part I, Figures: 

Page 1.  This page contains a location map, a zoom in on the float location as a function of time, where the black square is the deployment location, and a T/S plot of the top 300 meters of data.

Page 2.  Page 2 contains sections of float measurements as a function of depth (0 – 200 m) and time for:  oxygen concentration, oxygen saturation anomaly (%) {([O2]-[O2]sat)/[O2]sat}X100, temperature, and salinity.  The black line is the mixed layer depth (determined with a density threshold of 0.03 kg/m3)

Page 3. is a blow up of the oxygen saturation anomaly (%). 

Pages 4 and 5 demonstrate in situ optode calibration against atmospheric pO2. The top figue is atmospheric pressure from NCEP reanalysis at the float location. The next figure contains calculated atmospheric pO2 (black line), and measured atmospheric pO2 as a function of time (green and red lines).  The third figure is the percent difference between calculated and measured atmospheric pO2 and the final figure is the percent difference between calculated and measured atmospheric pO2 as a function of time.  The red line is the mean and the blue line a linear fit. 

Page 6 is afour panel summary figure containing: (a) a map of float location as a function of time, (b) T vs S in the top 300 m (~every fifth profile) as a function of time, (c) surface oxygen saturation anomaly (%) as a function of time (deltaO2 = {([O2]-[O2]sat)/[O2]sat}X100), and (d) oxygen concentration as a function of depth and time.

Page 7.  Concentration versus depth for O2, NO3, and pH (averages of every 5 profiles) for the BGC Argo floats.  The NO3 and pH data are copied from the BGC Argo data on the Monterey Bay Aquarium Research Institute (MBARI) website.

Page 8.  AOU versus NO3 for data from the BGC Argo floats

Part II, Data Files:

     Data from each of the floats are found in two Excel Files (.csv) that can be accessed by clicking on .csv files at the bottom of the opening page for each of the floats.  File ####_output.csv contains the float profile data and file ####_surf.csv contains the air calibration data. The column headings of these two spread sheets are indicated in the tables below.

                                    HEADINGS

Profile Data (####output.csv)

Column #  1.    2.    3.    4.    5.    6.     7.     8.    9.     10.     11. 12. 

Air Data (####surf.csv)

Column #  1.    2.    3.    4.    5.    6.    10.     11. 12.

                              Column number, Heading

1.  Float number

2.  Profile number (1, 2, 3…)

3.  Matlab time (days since Jan 1, year 0000)

4.  Excel time (days since Jan 1, 1900)

5.  Longitude (degrees, east is positive)

6.  Latitude (degrees, north is positive)

7.  Float pressure (decibars)

8.  Float temperature (deg C)

9.  Float salinity (PSS-78)

10.Optode t-phase (degrees)

11.Optode temperature (deg C)

12.Optode pO2 (atmospheres)

pO2 values in the last column (column 12) of the Profile Data are determined from measurements by optodes calibrated against atmospheric pO2 values. The calibration procedure is a two stage process (Bushinski et al., 2016, L&O Methods).  First, each optode was calibrated as a function of pO2 and temperature in the Emerson Lab resulting in the equation below where the “C” values are presented in the “Optode calibration table” located at the bottom of the list of floats numbers. Then, optodes on each float were calibrated against in situ atmospheric values during the lifetime of the float by comparing measured atmospheric pO2 to values determined from atmospheric pressure and pH2O, as illustrated in graphs on pages 4 and 5.

      pO2 = (((C(5)*t+C(4))/(C(6)+C(7)*y))-1)/(C(1)+C(2)*t+C(3)*t^2)                         

              where, t is optode temperature (deg C)

                         y is optode t-phase (degrees)