CTD History

CalCOFI CTD HISTORY

Summary: CalCOFI officially replaced the 20-bottle hydrowire cast with a Seabird 911 CTD-rosette in August 1993. Starting in Dec 1989, it took three years of testing, development, training, and comparisons to data collected by hydrowire bottle casts to switch over. At that time, CalCOFI performed 20-bottle hydrocasts on 66 stations and daily 6-bottle productivity casts. Since the 20 bottle hydrocast was mission critical and the Seabird CTD was new and untested, the first scientific deployments of the CTD-rosette replaced the primary productivity casts. Requiring only 6 bottles closed, a smaller rosette and pylon were used for these shallow casts.
When finally adopted for all station work on CalCOFI 9308NM, the CTD and sensors were mounted on a 24-bottle rosette frame. The separate hydrographic and primary productivity casts were combined into one 24-bottle CTD-rosette cast.
Other noteworthy events: the Seabird 911 system was upgraded to 911plus in 1998. At the same time, the General Oceanics 24-place pylons were replaced with a Seabird SBE32 carousels.
Originally deployed with one set of temperature & conductivity sensors, a second pair, with their own pump, was added July 1998.
LTER joined CalCOFI cruises in Nov 2004, adding an ISUS nitrate sensor to the CTD and additional seawater analyses.

Chronology & Changes

Cruise/Section	Date	Author	Description
9003JD	4 Mar 1990	J.Wilkinson	Seabird CTD first tested on CalCOFI; 13 casts; 10 bottles
9011NM	8-Nov-1990	J.Wilkinson	Second test of Seabird CTD on CalCOFI; 12 casts; 9 bottles.
9110NM	28-Sep-1991	J.Wilkinson	New and improved Seabird CTD tested; 13 casts; 12 bottles.
9202JD	29-Jan-1992	J.Wilkinson	Seabird CTD tested during prodo casts; 14 casts; 10 bottles
9204JD	26-Apr-1992	J.Wilkinson	One cast; conductive wire winch failure; hanging prodo cast on hydrowire
9207NM	02-Jul-1992	J.Wilkinson	Seabird CTD tested during prodo casts; 14 casts; 10 bottles
9210NM	26-Sep1992	J.Wilkinson	Seabird CTD used for prodo casts; 13 casts; 12 bottles; Ed Renger Prodo Cast operator
9308NM	11-Aug-1993	J.Wilkinson	Seabird CTD officially used for all 66 stations; 66 casts; 20 bottles
	26-May-1998	J.Wilkinson	CTD Sn 91338-1 (Homer) upgrade to 9plus; 3400m rating
	01-Jul-1998	J.Wilkinson	SBE32 Carousel Water Sampler replaces General Oceanics Pylon (Model 1015 purchased 8/1989)
	31-Aug-1998	J.Wilkinson	CTD SN 93235-0203 (Arnold) upgraded to 9plus; 2058 rated
9807NM	08-Jul-1998	J.Wilkinson	Added a second pair of temperature & conductivity; prompted by failure on previous cruise of the primary conductivity sensor - returned from calibration cracked.
0411RR	2-Nov-2004	J.Wilkinson	Satlantic ISUS nitrate sensor with battery pack added to CTD-rosette sensor array.
0907MH	14-Jul-2009	J.Wilkinson	New version 2 Deck Unit purchased (27-Mar-2009); offsets secondary conductivity automatically; plus complete new set of sensors: SBE14 Remote depth readout; SBE18 pH sensor; QSP-2300 PAR; Wetlabs C-Star transmissometer; Teledyne Altimeter (on older 'fish')
0911NM	6-Nov-2009	J.Wilkinson	New SBE9plus CTD (09P53161-0936; 6800m) deployed

California Cooperative Oceanic Fisheries Investigations

CTD History

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