# **GasEx 98 Leg 2 pCO~2~ Data Reduction Notes**

# 

**Cruise start: May 25, 1998 Lisbon Portugal**

**Cruise end June 26, 1998 Punta Del Gado Azores**

**Standard Tanks:**

**Low: 275.63 CC114999 1920 PSI**

**Mid: 297.74 CC117904 800 PSI**

**Hi: 360.62 CC106641 1990 PSI**

**Equilibrator Mercury Thermometer: Brooklyn Serial No. 75293**

**Thermistor Algorithm: 102.04 -- 48.88V + 10.785V^2^ -- 1.2714V^3^**

**Thermistor Calibration performed on April 8, 1998.**

***Notes from Green Log Book:***

**New reference mass flow meter installed prior to Leg 2. Serial \#
G6736, scale 0 -- 50. Original was used for SF~6~ system. The program
algorithm for converting voltage to flow was not changed, so all flows
should be multiplied by 4 to give accurate readings as the original MFM
had a scale of 0 -- 200.**

**During this leg WHOI teed off our system at the equilibrator and low
standard tank. Their system continuously measured the water fCO~2~ using
a Licor analyzer and exposed some leakage problems in the system. The
main leaks occurred in the garden hose fittings and were repaired on May
29. Also, the vent lines from the equilibrator fed into the hydro lab
instead of outside and some leakage also occurred in the condensor
glassware. These problems are noted below.**

**May 26, 2000 -- 2300: WHOI teeing off system.**

**May 27, 1100 -- 1246: Pressure check of system. STD 1 regulator
accidentally turned off.**

**May 27, 1530 -- 1546: Moved STD1 regulator. No reference flow.**

**May 28, 1840 -- 1850: WHOI working on their YSI.**

**May 29, 1830 -- 2030: Moved Dekoron vent lines from equilibrator which
were venting into the Hydro Lab. They now vent to open atmosphere above
the van aft of the Hydro Lab. Also closed off secondary drain (water) on
the bottom of the equilibrator. Replaced leaking washers in garden hose
fittings. After these repairs, WHOI no longer observed the spikes that
were previously apparent in their data.**

**May 30, 1500 -- 1800: YSI flow shut off. From 1400 to 1700 water flows
increased because CMDL turned off their equilibrator.**

**May 30, 2000: STD1 reference and sample flows found to be low.
Increased them.**

**May 30, 2330 -- 2400: Equilibrator water level too low. Positive
pressure in equilibrator caused headspace gas to back up into Licor
sample cell, resulting in bad readings.**

**May 31, 2115 -- 2300: Shut system down to install valve on sample
output of Licor. During air and STD phases, Licor now sends sample
output to atmosphere. During water phase sample output goes to
equilibrator as before.**

**June 1, 1100 Discovered leak in condensors. Tightened fittings,
greased O-ring , and tightened clamps.**

**June 1, 2342 Valve Mistrip.**

**June 2, 2049 & 2242 Valve Mistrip.**

**June 3, 1412 -- 1825: Shut down system to recalibrate YSI.**

**June 3, 2120 -- 2150: Reference gas disconnected while teed off
tank.**

**June 4, 1545: Valve Mistrip.**

**June 7, 2232 Valve Mistrip.**

**June 9, 545 -- 625: Cleaned equilibrator shower head.**

**June 11, 2333: Valve Mistrip.**

**June 12, 1225 -- 1312 Craig Neill changed the circuit controlling the
Valco actuator, inserting an Opto-coupler and eliminating the mechanical
relays that previously controlled it. This change eliminated the valve
mistrips the plagued the system in the past.**

**June 12, 1430 -- 1600: Recalibrated YSI O~2~ sensor.**

**June 17, 1505 -- 1930 Recalibrated YSI O~2~ sensor.**

**June 21, 1053: Increased water flow from \~ 9.9 to \~10.2 L/min.**

**June 23, 1320: Last CTD completed. Started steaming for Azores.**

**June 24, 1600: WHOI disconnected their equipment.**

**June 25, 1315 -- 1640: System hung up while I was explaining it to a
future operator. Mea Culpa.**

**June 26, 0700: Seawater supply off. System shut down. End of Leg 2.**

Below are rows where fixes have been made:

17. Interpolated GPS time and lat.

    6.  Interpolated Std mVs.

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325. Added row. Interpolated Jday, lat, lon, mV, SCS, & Eq temp.

326. Interpolated mV.

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590. Interpolated mV.

604,18,32 Interpolated mV.

683. Used previous hour's air xCO2 value for NEWxCO2.

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759. Mistrip. Used next value.

760. Mistrip. Interpolated.

     8.  Mistrip. Changed mV to --9.

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1040. Interpolated mV.

      64. Interpolated YSI sal.

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      6.  Mistrip. Used next value for STDs 1 & 2, interpolated STD 3.

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      31. System down for installation of solenoid valve. Added rows.
          Interpolated Jday, lat, lon, mV, SCS, & Eq temp.

2134,53,62 Interpolated SCS sal.

2225,31,33 Interpolated SCS sal.

2254,67 Interpolated SCS sal.

2345. Interpolated SCS sal.

2400,29,48 Interpolated SCS sal.

2467,76,88 Interpolated SCS sal.

2497. Interpolated SCS sal.

2501,11,16,

2527,32 Interpolated SCS sal.

2601. Interpolated YSI sal & DO.

      4.  Mistrip. Used next value for STDs 1 & 2, interpolated STD 3.

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      16. Mistrip. Used next value for STDs 1 & 2, interpolated STD 3.

3015-74 Recalibrating YSI -- system down. Added rows. Interpolated Jday,
lat, lon, mV, SCS, & Eq temp.

4.  Mistrip. Used next value for STDs 1 & 2, interpolated STD 3.

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3594. Interpolated SCS sal & temp.

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3630. Mistrip. Interpolated STD 3 mV.

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3731. Interpolated SCS sal & temp.

      4.  Mistrip. Used next value for STDs 1 & 2, interpolated STD 3.

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      6.  Mistrip. Used next value for STDs 1 & 2, interpolated STD 3.

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4778. Mistrip. Interpolated STD 3 mV.

      4904. Mistrip. Used next value for STDs 1 & 2, interpolated STD 3,
            changed others to --9.

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5118. Interpolated SCS sal.

      12. Mistrip. Used next value for STDs 1 & 2, interpolated STD 3.

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      92. Mistrip. Used next value for STDs 1& 2, interpolated STD 3,
          changed others to --9.

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      66. Recalibrating YSI -- system down. Added rows. Interpolated
          Jday, lat, lon, mV, SCS, & Eq temp.

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7152. Interpolated pressure.

      94. Recalibrating YSI. All YSI readings no good.

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      8.  Recalibrating YSI - system down. Added rows. Interpolated
          Jday, lat, lon, mV, SCS, & Eq temp.

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9664. Bad flow. Interpolated STD 3 mV.

10392 Interpolated YSI readings.

10394-440 System hung up. Added rows. Interpolated Jday, lat, lon, mV,
SCS, Eq Temp, and YSI readings.