Ocean Carbon and Biogeochemistry Data System

SOFeX 2002 Polar_Star cruise
OCB DMO notes for event log data

27 February 2007: Prepared for OCB data system by Cyndy Chandler, OCB DMO (WHOI).

6 February 2006: original Excel file downloaded from MBARI: copy of original Excel file

The cruise sampling event log for the 2002 Polar Star cruise was originally contributed by Chief Scientist, Ken Buesseler. In February 2007, the OCB DMO worked with Ken Buesseler to complete the cruise event log .

The following is a list of all changes made by the OCB DMO to the original event log Excel file:

1. calculated and added date, time, year day (yrDay) and event type (ev_type) and converted from deg, min, sec to decimal degrees for lat and lon using this formula:
   Conversion from Degrees, Minutes, and Seconds to Decimal Degrees
   Decimal Degrees = Degrees + (Minutes/60) + (Seconds/3600)
   Example: 66 degrees, 10 minutes, 28 seconds
   Decimal Degrees = 66 + (10/60) + (28/3600)
   Decimal Degrees = 66 + (0.1666667) + (0.0077778)
   Decimal Degrees = 66.17444
   
2. all the sampling events were done West of 180 degrees (W=negative longitude); however, it should be noted that the position data text file very clearly says that Longitude was East (and Lat was South). The data column headers are: " Latitude[S] Longitude[E] "
3. unique station number identifiers were provided by Matt Charette (WHOI, 1 March 2007) for the Ra events
4. position information for those events where it was lacking was taken from the ship's position log by matching date and time (TM_01 BC_01 BC_02 CTD_03 TM_02 TM_03 TM_04 TM_05 BC_05)
5. starting and ending position were entered for transect #1 #2 and #3
6. many of the events from 2/17 had positions reported differently (deg min and seconds); these were converted to decimal degrees to be consistent with rest of the database
7. originally the latitude for event 200202_1835 was reported as 65 degrees 50331 minutes; the final position reported in the event log was taken from the ship's position log at GMT 1835 on 20 February 2002.
8. event 190202_0645 (Trace Metal 6 cast) was originally listed between events 180202_2315 (Bottle_Cast_6) and 190202_0530 (CTD-4) which leads me to suspect the reported time for event 190202_0645 or perhaps the events before/after that one; PI note: TM/Trace Metal casts were independent casts performed by Russel Frew (New Zealand) and Peter Croot (pcroot@ifm-geomar.de)
9. all CTD station positions changed to match the NMEA HDR records; start times were unchanged (event numbers not changed)
10. added event entry for CTD station 3 (CTD 3x was aborted)
11. OCB DMO added events for start and end of Transect 2 and 3 using data from ship's position log
12. the ship's position log and bottle_samples data file was used to determine the start of the 3 transects; information about the transect sampling lines is given in:
    Buesseler, K.O., J.E. Andrews, S. Pike, M.A. Charette, L.E. Goldson, M.A. Brzezinski and V.P. Lance (2005). Particle export during the Southern Ocean Iron Experiment (SOFeX). Limnology and Oceanography, 50: 311-327. [PDF file]