Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Data Files
• Parameters
• Instruments
• Deployments
• Project Information
• Program Information
• Funding

CTD data from cruise AT18-02 in the Gulf of Mexico (November 26, 2010 to December 2, 2010).

All CTD sensors were calibrated by U Miami or WHOI technicians prior to sailing except the CDOM sensor, which was obtained directly from WETLABS by collaborator V. Asper. That instrument was calibrated by Wetlabs. CTD casts in the vicinity of the Macondo Wellhead were complicated by the presence of oil on the sea surface. A saltwater hose was used to spray the sea surface, parting the oil to create a clean area for the CTD to be dropped through; a similar procedure was used for deployment and recovery.

Header information from Sea-Bird SBE 9 data files:
Software Version Seasave V 7.20f
Temperature SN = 4195; Conductivity SN = 2670
Number of Bytes Per Scan = 37; Number of Voltage Words = 4
Number of Scans Averaged by the Deck Unit = 1
units = specified

Station 9 (casts 19 and 20):
name 0 = latitude: Latitude [deg]
name 1 = longitude: Longitude [deg]
name 2 = timeS: Time, Elapsed [seconds]
name 3 = prDM: Pressure, Digiquartz [db]
name 4 = depSM: Depth [salt water, m]
name 5 = t090C: Temperature [ITS-90, deg C]
name 6 = t190C: Temperature, 2 [ITS-90, deg C]
name 7 = c0S/m: Conductivity [S/m]
name 8 = c1S/m: Conductivity, 2 [S/m]
name 9 = sal00: Salinity, Practical [PSU]
name 10 = sal11: Salinity, Practical, 2 [PSU]
name 11 = density00: Density [density, Kg/m^3]
name 12 = density11: Density, 2 [density, Kg/m^3]
name 13 = avgsvCM: Average Sound Velocity [Chen-Millero, m/s]
name 14 = sbeox0V: Oxygen raw, SBE 43 [V]
name 15 = sbeox0Mm/Kg: Oxygen, SBE 43 [umol/Kg]
name 16 = oxsatMm/Kg: Oxygen Saturation, Weiss [umol/Kg]
name 17 = xmiss: Beam Transmission, Chelsea/Seatech/WET Labs CStar [%]
name 18 = potemp090C: Potential Temperature [ITS-90, deg C]
name 19 = potemp190C: Potential Temperature, 2 [ITS-90, deg C]
name 20 = flECO-AFL: Fluorescence, WET Labs ECO-AFL/FL [mg/m^3]
name 21 = turbWETntu0: Turbidity, WET Labs ECO [NTU]
name 22 = wetCDOM: Fluorescence, WET Labs CDOM [mg/m^3]
name 23 = flCUVA: Fluorescence, Chelsea UV Aquatracka [ug/l]
name 24 = flScufa: Fluorescence, Turner SCUFA [ppb]
name 25 = altM: Altimeter [m]
name 26 = nbf: Bottles Fired
name 27 = modError: Modulo Error Count
interval = decibars: 1; bad_flag = -9.990e-29; Sensors count=13

Cast 21:
name 0 = scan: Scan Count
name 1 = latitude: Latitude [deg]
name 2 = longitude: Longitude [deg]
name 3 = nbf: Bottles Fired
name 4 = depSM: Depth [salt water, m]
name 5 = t090C: Temperature [ITS-90, deg C]
name 6 = t190C: Temperature, 2 [ITS-90, deg C]
name 7 = sal00: Salinity, Practical [PSU]
name 8 = sal11: Salinity, Practical, 2 [PSU]
name 9 = sbeox0Mg/L: Oxygen, SBE 43 [mg/l]
name 10 = sbeox0PS: Oxygen, SBE 43 [% saturation]
name 11 = density00: Density [density, Kg/m^3]
name 12 = sigma-é00: Density [sigma-theta, Kg/m^3]
name 13 = bat: Beam Attenuation, Chelsea/Seatech/WET Labs CStar [1/m]
name 14 = xmiss: Beam Transmission, Chelsea/Seatech/WET Labs CStar [%]
name 15 = flECO-AFL: Fluorescence, WET Labs ECO-AFL/FL [mg/m^3]
name 16 = wetCDOM: Fluorescence, WET Labs CDOM [mg/m^3]
name 17 = flCUVA: Fluorescence, Chelsea UV Aquatracka [ug/l]
name 18 = prDM: Pressure, Digiquartz [db]
name 19 = turbWETntu0: Turbidity, WET Labs ECO [NTU]
name 20 = flag:  0.000e+00       
interval = seconds: 0.0416667; bad_flag = -9.990e-29; Sensors count=13

Casts 22 through 26:
name 0 = scan: Scan Count
name 1 = latitude: Latitude [deg]
name 2 = longitude: Longitude [deg]
name 3 = t190C: Temperature, 2 [ITS-90, deg C]
name 4 = t090C: Temperature [ITS-90, deg C]
name 5 = sal00: Salinity, Practical [PSU]
name 6 = sal11: Salinity, Practical, 2 [PSU]
name 7 = potemp090C: Potential Temperature [ITS-90, deg C]
name 8 = depSM: Depth [salt water, m]
name 9 = c0S/m: Conductivity [S/m]
name 10 = bat: Beam Attenuation, Chelsea/Seatech/WET Labs CStar [1/m]
name 11 = xmiss: Beam Transmission, Chelsea/Seatech/WET Labs CStar [%]
name 12 = nbf: Bottles Fired
name 13 = density00: Density [density, Kg/m^3]
name 14 = sigma-é00: Density [sigma-theta, Kg/m^3]
name 15 = flECO-AFL: Fluorescence, WET Labs ECO-AFL/FL [mg/m^3]
name 16 = wetCDOM: Fluorescence, WET Labs CDOM [mg/m^3]
name 17 = flCUVA: Fluorescence, Chelsea UV Aquatracka [ug/l]
name 18 = sbeox0Mg/L: Oxygen, SBE 43 [mg/l]
name 19 = sbeox0PS: Oxygen, SBE 43 [% saturation]
name 20 = prDM: Pressure, Digiquartz [db]
name 21 = flag:  0.000e+00          
interval = seconds: 0.0416667; bad_flag = -9.990e-29; Sensors count=13

sensor channel 1 = Frequency 0, Temperature; Sensor ID: 55; SerialNumber: 4195
Calibration Date: 23-Jan-10

sensor channel 2 = Frequency 1, Conductivity; Sensor ID: 3; Serial Number: 2670
Calibration Date: 12-Jan-10

sensor channel 3 = Frequency 2, Pressure, Digiquartz with TC; Sensor ID: 45; Serial Number: 63505 SBE090462
Calibration Date: 12/23/2002

sensor channel 4 = Frequency 3, Temperature, 2; Sensor ID: 55; Serial Number: 4481
Calibration Date: 12-Jan-10

sensor channel 5 = Frequency 4, Conductivity, 2; Sensor ID: 3; Serial Number: 2880
Calibration Date: 12-Jan-10
     
sensor channel 6 = A/D voltage 0, Fluorometer, WET Labs ECO-AFL/FL; Sensor ID: 20 SerialNumber: FLNTURTD-FL-1012
Calibration Date: 2008-04-18

sensor channel 7 = A/D voltage 1, Turbidity Meter, WET Labs, ECO-NTU;  Sensor ID: 67; Serial Number: FLNTURTD-1012
Calibration Date: 2008-04-18

sensor channel 8 = A/D voltage 2, Fluorometer, WET Labs CDOM; Sensor ID: 19; Serial Number: FLCDRTD-1379
Calibration Date: 4/14/2010

sensor channel 9 = A/D voltage 3, Fluorometer, Turner SCUFA; Sensor ID: 17; Serial Number: 201011
Calibration Date: 2010-Aug-18

sensor channel 10 = A/D voltage 4, Altimeter; Sensor ID: 0; Serial Number PSA916-1162
Calibration Date: (blank)

sensor channel 11 = A/D voltage 5, Oxygen, SBE 43; Sensor ID: 38; Serial Number: 0723
Calibration Date: 12-Feb-10
      
sensor channel 12 = A/D voltage 6, Transmissometer, Chelsea/Seatech/WET Lab CStar; Sensor ID: 59 Serial Number: CST-1118DR
Calibration Date: 2008-04-30

sensor channel 13 = A/D voltage 7, Fluorometer, Chelsea UV Aquatracka; Sensor ID: 7; Serial Number: 107733001
Calibration Date: 2010-8-18
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The CTD data were processed on Seasave software version 7.20f as per routine operating procedures.

BCO-DMO made the following modifications:
- Removed duplicate parameters from display.
- Changed parameter names to conform with BCO-DMO conventions.
- Added date_start_utc, time_start_utc, lat_start, and lon_start from the header information in the original CTD files.
- Files named '12.04' were assumed to be be '12.05', based on the event log.

During late spring and summer of 2010, the Northern Gulf of Mexico (GoM) was exposed to an oil spill different in magnitude and scope from any previous spill. The Deepwater Horizon, an ultra-deep, offshore drilling platform, began working GoM oil fields in 2001. While working a well in Mississippi Canyon on April 20, 2010, a bolus of methane gas ascended the drill pipe and exploded at the surface. Two days later the platform sank and since then, substantial quantities of oil and gas have leaked from the damaged wellhead. This work addressed the offshore oceanic impacts of the BP spill.

Sediment microbial mediated processes are capable of oxidizing oil and methane in the environment. The PI's examined the impacts of the Deepwater Horizon Oil Spill on microbially mediated processes in the deep waters and sediments in the vicinity of the spill site. The work complemented several funded or planned geochemical and microbiological sampling programs focused on the oil spill response. PI's evaluated rates of water column methane oxidation and sediment sulfate reduction and methanogenesis at multiple sites around the spill site. Additional experiments quantified the impact of nutrients, oxygen and substrate concentrations on these important microbially mediated processes.

The Joye group participated in six research cruises during 2010 and received samples from another six cruises from the study area. On all cruises, water samples were collected using a CTD rosette and Niskin or Go-Flo bottles. Sediment samples were obtained by box coring, multi-coring, or using the manned submersible ALVIN.

The PI's extended the monitoring/assessment program that was initiated through the NOAA National Institute of Undersea Science and Technology (NIUST) funded cruise and further leveraged by NOAA/NIUST (cruises in July 2010, October 2010) by conducting three major expeditions in 2010. This RAPID project directly supported the PI's efforts for cruises in May/June 2010 (NSF Joye chief scientist); August 2010 (NSF Montoya, chief scientist); November/December 2010 (NSF Joye chief scientist); and July 2011 (NSF Montoya, chief scientist)

GOM - Broader Impacts
The need to understand the impact of this largest oil spill to date on ecosystems and biochemical cycling is self evident. The consequences of the disaster and accompanying clean up measures (e.g. the distribution of dispersants) need to be evaluated to guide further mediating measures and to develop and improve responses to similar disasters in the future. Would it be advantageous if such oil aggregates sink, or should it rather remain suspended? Possibly measures can be developed to enhance sinking or suspension (e.g. addition of ballast minerals) once we understand their current formation and fate. Understanding the particle dynamics following the input of large amounts of oil and dispersants into the water is a prerequisite to develop response strategies for now and in the future.