Cruise inventory

RRS Discovery D381B

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS Discovery (74E3)
Cruise identifierD381B
Cruise period2012-09-14 — 2012-10-03
StatusCompleted
Port of departureFalmouth, United Kingdom
Port of returnSouthampton, United Kingdom
PurposeResearch
ObjectivesD381B is a process study cruise to support the NERC's Ocean Surface Boundary layer theme action programme, OSMOSIS (Ocean Surface Mixing, Ocean Sub-mesoscale Interaction Study). The ocean surface boundary layer (OSBL) deepens in response to convective, wind and surface wave forcing, which produce three-dimensional turbulence that entrains denser water, deepening the layer. The OSBL shoals in response to solar heating and to mesoscale and sub-mesoscale motions that adjust lateral buoyancy gradients into vertical stratification. Recent and ongoing work is revolutionising our view of both the deepening and shoaling processes: new processes are coming into focus that are not currently recognised in model parameterisation schemes. In OSMOSIS we have a project which integrates observations, modelling studies and parameterisation development to deliver a step change in modelling of the OSBL. The OSMOSIS overall aim is to develop new, physically based and observationally supported, parameterisations of processes that deepen and shoal the OSBL, and to implement and evaluate these parameterisations in a state-of-the-art global coupled climate model, facilitating improved weather and climate predictions. To support this, D381B has firstly completed mooring and glider deployment work begun during the preceding D381A cruise. Secondly we have carried out several days of targetted turbulence profiling for looking at changes in turbulent energy dissipation resulting from the interation of upper ocean fluid structures such as eddies, sub-mesoscale filaments and Langmuir cells with surface wind and current shear. Finally we have carried out two spatial surveys with the towed SeaSoar vehicle to map and diagnose the mesoscale and sub-mesoscale flows, which, unusually, are the 'large scale' background in which this study sits.
Chief scientistJohn T Allen (National Oceanography Centre, Southampton)
ProjectOcean Surface Mixing, Ocean Submesoscale Interaction Study (OSMOSIS), FASTNEt
Cruise reportRRS Discovery D381B cruise report d381.pdf — access key 'C' (9.63 MB) 
Ocean/sea areas 
GeneralCeltic Sea
SpecificPorcupine Abyssal Plain site centred around 48° 40’ N, 16° 10’ W, and a square box of side length ~ 50 nautical miles centred approximately around this point.
Track chartsRRS Discovery D381B cruise track — d381btrk.pdf (00 MB) 
Measurements 
Physical oceanography 
Surface measurements underway (T,S)Quantity: activity duration in days = 16
Description: RRS Discovery thermosalinograph data: Conductivity, Temperature, Fluorescence, Optical Transmittance, Wind Velocity, Photosynthetic Available Radiation (PAR), Total Incident Radiation, Air Temperature and Atmospheric Pressure. Underway sampling hourly for Chlorophyll(a), Nutrients and Salinity, 4 hourly for POC, HPLC, BSi, PIC and SEM counts.
BathythermographQuantity: number of profiles = 4
Description: XBT launches: Temperature
CTD stationsQuantity: number of stations = 18
Description: CTD station numbers 381005 - 381022; Conductivity, Temperature, Fluorescence, Optical Transmittance, Oxygen, PAR, Lowered ADCP (LADCP), Optical backscatter. Samples taken typically 4, 6, 8, 12 or 24 depths for Salinity, Oxygen, Nutrients, Chlorophyll(a), POC, HPLC, BSi, PIC, SEM counts.
Subsurface temperature and salinity measurementsQuantity: track kilometres = 1590
Description: Towed SeaSoar profiles: Conductivity, Temperature, Fluorescence x 2, Fast Repetition Rate Fluorometer, Oxygen x 2, PAR, Phycoerythrin fluorescence, Phycocyanin fluorescence, Optical backscatter, Laser Optical Particle Counter, Bioluminescence, SUV6/51 UV absorption nitrate.
Other physical oceanographic measurementsQuantity: number of profiles = 692
Description: ISW MSS90 turbulence profiles: Conductivity, Temperature, Shear strain x 2, Micro-structure Temperature
Moorings, landers, buoys 
Physical oceanography 
Subsurface temperature and salinity measurements48° 8' 47" N  9° 40' 53" W — SAMS glider Talisker, Conductivity, Temperature, Pressure, Oxygen and Fluorescence, deployed for the FASTNET project
Subsurface temperature and salinity measurements48° 7' 41" N  9° 41' 35" W — SAMS glider Ardbeg, Conductivity, Temperature, Pressure, Oxygen and Fluorescence, deployed for the FASTNET project
Subsurface temperature and salinity measurements47° 59' 17" N  10° 56' 35" W — NOCS glider Coprolite recovery
Subsurface temperature and salinity measurements48° 46' 35" N  16° 22' 35" W — NOCL turbulence glider, Conductivity, Temperature, turbulent shear
Subsurface temperature and salinity measurements48° 0' 29" N  10° 57' 53" W — SAMS glider Ardbeg recovery
Subsurface temperature and salinity measurements48° 42' 47" N  16° 5' 53" W — NOCL turbulence glider recovery
Current meters48° 37' 59" N  16° 6' 23" W — OSMOSIS south east outer mooring deployed, 5 current meters, and 5 CTs; one each at approximately 50 m, 110 m, 225 m, 350 m and 510m.
Instrumented wave measurements48° 43' 35" N  16° 2' 47" W — SAMS wave-rider buoy recovery
Other physical oceanographic measurements48° 46' 35" N  16° 22' 35" W — NOCL turbulence glider, Conductivity, Temperature, turbulent shear
Other physical oceanographic measurements48° 37' 59" N  16° 6' 23" W — OSMOSIS south east outer mooring deployed, 5 current meters, and 5 CTs; one each at approximately 50 m, 110 m, 225 m, 350 m and 510m.
Other physical oceanographic measurements48° 42' 47" N  16° 5' 53" W — NOCL turbulence glider recovery
Data held at BODC 
Series/Profiles 
17  CTD/STD cast
Density of the water column
Transmittance and attenuance of the water column
Electrical conductivity of the water column
Chlorophyll pigment concentrations in water bodies
Vertical spatial coordinates
Salinity of the water column
Optical backscatter
Temperature of the water column
Reference numbers
Dissolved oxygen parameters in the water column
Density of the water column
Transmittance and attenuance of the water column
Electrical conductivity of the water column
Chlorophyll pigment concentrations in water bodies
Vertical spatial coordinates
Salinity of the water column
Optical backscatter
Temperature of the water column
Reference numbers
Dissolved oxygen parameters in the water column

BODC idDate/TimeLocationDoc.
17237842012-09-15 19:48 48° 9' 2" N  9° 42' 7" W  View metadata report for BODC series reference number 1723784
17237962012-09-17 12:06 48° 36' 19" N  16° 3' 52" W  View metadata report for BODC series reference number 1723796
17238032012-09-17 21:15 48° 48' 45" N  16° 22' 5" W  View metadata report for BODC series reference number 1723803
17238152012-09-18 15:38 48° 48' 26" N  16° 21' 38" W  View metadata report for BODC series reference number 1723815
17238272012-09-19 12:36 48° 58' 50" N  16° 22' 31" W  View metadata report for BODC series reference number 1723827
17238392012-09-21 20:18 48° 16' 54" N  16° 50' 57" W  View metadata report for BODC series reference number 1723839
17238402012-09-21 22:22 48° 24' 6" N  16° 41' 5" W  View metadata report for BODC series reference number 1723840
17238522012-09-22 00:26 48° 31' 15" N  16° 31' 11" W  View metadata report for BODC series reference number 1723852
17238642012-09-28 08:19 48° 58' 31" N  16° 5' 26" W  View metadata report for BODC series reference number 1723864
17238762012-09-28 10:35 48° 58' 33" N  16° 3' 46" W  View metadata report for BODC series reference number 1723876
17238882012-09-28 13:40 48° 58' 58" N  16° 3' 45" W  View metadata report for BODC series reference number 1723888
17239072012-09-28 16:26 49° 0' 29" N  16° 4' 7" W  View metadata report for BODC series reference number 1723907
17239192012-09-29 00:23 49° 3' 34" N  16° 4' 40" W  View metadata report for BODC series reference number 1723919
17239202012-09-29 03:45 49° 5' 3" N  16° 28' 19" W  View metadata report for BODC series reference number 1723920
17239322012-09-29 05:44 49° 5' 49" N  16° 39' 51" W  View metadata report for BODC series reference number 1723932
17239442012-09-30 09:00 48° 11' 40" N  15° 30' 28" W  View metadata report for BODC series reference number 1723944
17239562012-10-01 09:06 47° 59' 22" N  10° 56' 31" W  View metadata report for BODC series reference number 1723956
Discrete samples 
16  CTD frame plus rosette samplerChlorophyll pigment concentrations in water bodies
Salinity of the water column
Dissolved oxygen parameters in the water column
242  Sample taken from ship's non-toxic supplyChlorophyll pigment concentrations in water bodies