Metadata Report for BODC Series Reference Number 2022236
Metadata Summary
Problem Reports
Data Access Policy
Narrative Documents
Project Information
Data Activity or Cruise Information
Fixed Station Information
BODC Quality Flags
SeaDataNet Quality Flags
Metadata Summary
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Problem Reports
No Problem Report Found in the Database
DY096 VMADCP Quality Control Report
There were 9 gaps identified in the data throughout the cruise. These gaps are:
- 30 November 2018 09:08:15 hours to 30 November 2018 09:15:55 hours
- 30 November 2018 09:20:55 hours to 30 November 2018 09:31:32 hours
- 30 November 2018 09:58:42 hours to 30 November 2018 10:23:49 hours
- 30 November 2018 12:11:29 hours to 30 November 2018 12:27:25 hours
- 30 November 2018 12:40:41 hours to 30 November 2018 13:47:28 hours
- 30 November 2018 13:47:28 hours to 30 November 2018 14:10:33 hours
- 30 November 2018 14:10:33 hours to 30 November 2018 14:24:02 hours
- 01 December 2018 04:50:08 hours to 02 December 2018 17:11:53 hours
- 08 December 2018 11:37:41 hours to 08 December 2018 14:51:17 hours
Data Access Policy
Open Data supplied by Natural Environment Research Council (NERC)
You must always use the following attribution statement to acknowledge the source of the information: "Contains data supplied by Natural Environment Research Council."
Narrative Documents
RD Instruments- Ocean Surveyor 75kHz Vessel mounted ADCP.
Long-Range Mode | ||
---|---|---|
Vertical Resolution Cell Size3 | Max. Range (m)1 | Precision (cm/s)2 |
8m | 520 - 650 | 30 |
16m | 560 - 700 | 17 |
High-Precision Mode | ||
Vertical Resolution Cell Size3 | Max. Range (m)1 | Precision (cm/s)2 |
8m | 310 - 430 | 12 |
16m | 350 - 450 | 9 |
1 Ranges at 1 to 5 knots ship speed are typical and vary with situation.
2 Single-ping standard deviation.
3 User's choice of depth cell size is not limited to the typical values specified.
Profile Parameters
- Velocity long-term accuracy (typical): ±1.0%, ±0.5cm/s
- Velocity range: -5 to 9m/s
- # of depth cells: 1 - 128
- Max ping rate: 0.7
Bottom Track
Maximum altitude (precision <2cm/s): 950m
Echo Intensity Profile
Dynamic range: 80dB
Precision: ±1.5dB
Transducer and Hardware
Beam angle: 30°
Configuration: 4-beam phased array
Communications: RS-232 or RS-422 hex-ASCII or binary output at 1200 - 115,200 baud
Output power: 1000W
Standard Sensors
Temperature (mounted on transducer)
- Range: -5° to 45°C
- Precision: ±0.1°C
- Resolution: 0.03°
Environmental
Operating temperature: -5° to 40°C (-5° to 45°C)*
Storage temperature: -30° to 50°C (-30° to 60°C)*
*later instruments have greater range.
Web Page
Further details can be found on the manufacturer's website or in the specification sheet
DY096 CUSTARD 75 kHz Shipboard ADCP Originator Data Processing
This document describes the instrument setup and data processing steps of the 75 kHz vessel-mounted Acoustic Doppler Current Profiler (ADCP) during RRS Discovery DY096 cruise as part of the CUSTARD research project. The following information was extracted from the cruise report and data processing files submitted by the originator.
ADCP data collection and preliminary processing
The 75 kHz Ocean Surveyor ADCP was operated during the cruise to measure the horizontal velocity field throughout the top 800 m of the water column. The instrument was mounted on the hull of the ship, with the Y-axis transducer (beam 3) rotated by -45 degrees relative to the ship?s central line. Version 1.48 of the RDI VMDAS software was used for data acquisition, typically carried out in daily file segments, and preliminary data processing, which included data screening and conversion from beam to earth coordinates.
The following configuration was set up to facilitate data collection and preliminary processing:
Variable | Setting |
---|---|
Data mode | Narrowband single-ping profile |
Beam angle | 30 deg |
Heading offset | -45 deg |
Sampling interval | 300 sec |
Number of Bins | 45 |
Bin size | 16 m |
Blanking distance | 8 m |
Transducer depth | 6 m |
Bottom track mode | OFF |
Data post-processing
Preliminary-processed data were converted into the University of Hawaii Linux acquisition system format, UHDAS, and fed into the Common Ocean Data Access System (CODAS) software package for secondary processing. This included the removal of ship velocity, and correction of the gyro heading with GPS-derived heading; water-track data was then used to estimate the heading misalignment (as no bottom track data were collected for the duration of the cruise).
The data were then reprocessed by applying a scale transducer offset of 3 m in the forward direction, and the median calibration values obtained in the previous step:
- Amplitude data correction = 1.022
- Phase data correction = 1.5
Manual inspection and editing of bad data ensued, before finally exporting the final ADCP velocity data into netCDF format.
DY096 CUSTARD Vessel Mounted ADCP data: BODC Processing
The data arrived at BODC in one MSTAR file, representing the data collected from the vessel mounted ADCP during cruise DY096. The data were reformatted to BODC's internal NetCDF format.
The following table shows the mapping of the originator's variables, from the MSTAR file, to the appropriate BODC parameter codes:
Originator's Variable | Originator's Units | BODC Parameter Code | BODC Units | Comment |
---|---|---|---|---|
lat | degrees_north | ALATGP01 | Degrees | - |
lon | degrees_east | ALONGP01 | Degrees | - |
uship | meter second-1 | APEWGP01 | cm/s | Conversion *100 applied |
vship | meter second-1 | APNSGP01 | cm/s | Conversion *100 applied |
u | meter second-1 | LCEWAS01 | cm/s | Conversion *100 applied |
v | meter second-1 | LCNSAS01 | cm/s | Conversion *100 applied |
depth | m | DBINAA01 | m | - |
heading | degrees | - | - | Not transferred |
amp | db | - | - | Not transferred |
pg | % | - | - | Not transferred |
tr_temp | Celsius | - | - | Not transferred |
The reformatted data were visualised using the in-house EDSERPLO software. Suspect data were marked by adding an appropriate quality control flag, missing data by both setting the data to an appropriate value and setting the quality control flag.
Parameters found in the originator's file, that were not transferred, are available upon request.
Project Information
Carbon Uptake and Seasonal Traits of Antarctic Remineralisation Depth (CUSTARD)
Carbon Uptake and Seasonal Traits of Antarctic Remineralisation Depth (CUSTARD) is a £1.8 million, four-year (2018-2022) research project funded by the Natural Environment Research Council (NERC).
The main aim of the CUSTARD project is to quantify the seasonal drivers of carbon fluxes in a region of the Southern Ocean upper limb, and estimate how long different quantities of carbon are kept out of the atmosphere based on the water flow routes at the observed remineralisation depths. Please visit the CUSTARD web page for more information
CUSTARD is one of three projects funded as part of the Role of the Southern Ocean in the Earth System (RoSES) programme, also known as the Southern Ocean programme. Please see the RoSES project document for more information on the wider programme and the research projects associated with it.
Background
The upper limb of the Antarctic Circumpolar Current (ACC) represents an important junction in the marine carbon cycle, as the fate of carbon fixed by surface phytoplankton will differ according to how deep it penetrates before being remineralised. If shallow remineralisation occurs, carbon will follow the upper limb circulation and upwell further north, escaping into the atmosphere within decades. On the other hand, deep remineralisation will result in carbon entering the lower limb circulation, with the potential of being retained in the ocean for hundreds of years. Seasonality in plankton dynamics play an important role in remineralisation depth, and CUSTARD aims to resolve all factors contributing to the carbon export out of the region.
Participants
Six different UK-based organisations are directly involved in research for CUSTARD:
- National Oceanography Centre (NOC)
- NERC British Antarctic Survey (BAS)
- University of Southampton
- University of Oxford
- Plymouth University
- University of East Anglia (UEA)
CUSTARD collaborates closely with the US Ocean Observatories Initiative (OOI) program through sharing of instruments and platforms at and around the Global Southern Ocean Array. OOI is funded by the National Science Foundation (NSF) and is managed by the Woods Hole Oceanographic Institution. Rutgers University maintains the cyberinfrastructure component, working alongside CUSTARD scientists in the handling and distribution of shared observational data.
Research details
Four Work Packages have been funded by the CUSTARD project, each addressing a separate project objective within the region of study in the south eastern Pacific ocean. These are described briefly below:
-
Work Package 1: Obtain an accurate picture of the seasonal air-sea flux and macronutrient drawdown.
This work package aims at determining the magnitude and variability of air-sea CO2 fluxes and their physical and biogeochemical drivers. High-resolution carbon measurements in the water column, CO2 flux estimates and daily resolved nitrate and silicate observations are combined to better understand the link between seasonal changes in CO2 fluxes and biological variability. -
Work Package 2: Quantify the link between iron and silicate availability and remineralisation depth.
This work package investigates the annual cycle of phytoplankton dynamics, net production and export of organic material in conjunction with iron availability. -
Work Package 3: Observationally determine the seasonal cycle in remineralisation depth.
This work package assesses remineralisation depth and its variability using marine snow catchers deployed during the process cruise, and backscatter measurements carried out year-round by gliders. -
Work Package 4: Examine the link between seasonality and remineralisation depth and the trajectory of carbon from the surface out of the upper limb.
This work package aims to ingest all CUSTARD observational data into models to determine whether seasonal variability in phytoplankton composition is reflected in changes in remineralisation depth, which in turn leads to seasonal variability in the fate of organic carbon leaving the Southern Ocean via the upper limb.
Fieldwork and data collection
All the observational data from the project is collected at and south of the Ocean Observatories Initiative (OOI) Global Southern Ocean Array, located south-west of Chile. Data collection activities span from November 2018 to January 2020, and include three cruises, four glider missions, and one mooring.
Cruises
All cruises depart from and return to Punta Arenas (Chile). Cruise activities include deployments and recovery of gliders and a mooring, Conductivity, Temperature and Depth (CTD), trace metal clean GoFlo bottle sampling, Red Camera Frame, Marine Snow Catcher and Underwater Vision Profiler deployments, as well as laboratory incubations with sea water samples. See cruise details below:
Cruise identifier | Research ship | Cruise dates | Comments |
---|---|---|---|
DY096 | RRS Discovery | November - December 2018 | Deployment cruise |
DY111 | RRS Discovery | December 2019 - January 2020 | Process cruise |
DY112 | RRS Discovery | January 2020 | Mooring recovery cruise |
Gliders
Two Slocum 1000 MARS gliders (Pancake and Churchill) are deployed from DY096, to collect data continuously for one year until recovery on DY111. The gliders are mounted with CTD sensors, an optode, a fluorometer, and twin backscatter sensors. Pancake failed and its mission ended early in February 2019.
One Rutgers University glider is deployed from DY111, to collect data until recovery at the end of the same cruise. The glider is owned by Rutgers University and the data is shared with CUSTARD. It carries CTD sensors, an optode, a fluorometer, a backscatter sensor and a particle size analyser.
Mooring
Deployment of Global Surface Mooring GS01SUMO-00004 (SUMO-4) during DY096, to take continuous measurements for approximately one year until recovery during DY112. Its location is roughly 54 28 S, 89 02 W. This is an OOI mooring provided and deployed by WHOI, and adapted to integrate NOC lab-on-chip nitrate and silicate sensors.
Contacts
Dr. Adrian Marin (National Oceanography Centre, UK) - Lead Principal Investigator and lead of Work Package 4
Dr. Dorothee Bakker (University of East Anglia, UK) - Lead of Work Package 1
Prof. Mark Moore (University of Southampton, UK) - Lead of Work Package 2
Dr. Stephanie Henson (National Oceanography Centre / University of Southampton, UK) - Lead of Work Package 3
Data Activity or Cruise Information
Cruise
Cruise Name | DY096 |
Departure Date | 2018-11-28 |
Arrival Date | 2018-12-14 |
Principal Scientist(s) | Adrian P Martin (National Oceanography Centre, Southampton) |
Ship | RRS Discovery |
Complete Cruise Metadata Report is available here
Fixed Station Information
No Fixed Station Information held for the Series
BODC Quality Control Flags
The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:
Flag | Description |
---|---|
Blank | Unqualified |
< | Below detection limit |
> | In excess of quoted value |
A | Taxonomic flag for affinis (aff.) |
B | Beginning of CTD Down/Up Cast |
C | Taxonomic flag for confer (cf.) |
D | Thermometric depth |
E | End of CTD Down/Up Cast |
G | Non-taxonomic biological characteristic uncertainty |
H | Extrapolated value |
I | Taxonomic flag for single species (sp.) |
K | Improbable value - unknown quality control source |
L | Improbable value - originator's quality control |
M | Improbable value - BODC quality control |
N | Null value |
O | Improbable value - user quality control |
P | Trace/calm |
Q | Indeterminate |
R | Replacement value |
S | Estimated value |
T | Interpolated value |
U | Uncalibrated |
W | Control value |
X | Excessive difference |
SeaDataNet Quality Control Flags
The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:
Flag | Description |
---|---|
0 | no quality control |
1 | good value |
2 | probably good value |
3 | probably bad value |
4 | bad value |
5 | changed value |
6 | value below detection |
7 | value in excess |
8 | interpolated value |
9 | missing value |
A | value phenomenon uncertain |
B | nominal value |
Q | value below limit of quantification |