Dataset: VPR Data from TN376 and RR2004

Name: VPR images and log files from cruise RR2004 in the Pacific Sector of the Southern Ocean and cruise TN376 in the South Indian Ocean (Jan 2020 to Feb 2021)
Published: 2023-07-11
Keywords: oceans

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Project:

Collaborative Research: Biogeochemical and Physical Conditioning of Sub-Antarctic Mode Water in the Southern Ocean (Conditioning_SAMW)

BCO-DMO Data Manager:

Amber D. York (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Version:

Version Date:

2023-07-11

Restricted:

Validated:

Current State:

Data not available

VPR images and log files from cruise RR2004 in the Pacific Sector of the Southern Ocean and cruise TN376 in the South Indian Ocean (Jan 2020 to Feb 2021)

Abstract:

VPR images and log files from R/V Roger Revelle cruise RR2004 in the Pacific Sector of the Southern Ocean along 150W from Jan-Feb of 2020 and R/V Thomas G. Thompson cruise TN376 in the South Indian Ocean from Jan-Feb of 2021.

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Methods & Sampling

Location:

R/V Thomas G. Thompson cruise TN376: South Indian Ocean
R/V Roger Revelle cruise RR2004: Pacific Sector of the Southern Ocean along 150W|

Methods & Sampling:

To assess the large microplankton and small mesoplankton community alongside fine-scale measurements of temperature, salinity, and fluorescence, a Video Plankton Recorder II (VPR, from SeaScan Inc.) was towed behind the ship across the shelf break. The VPR consists of a towed body, containing a Seabird Electronics Inc. CTD (SBE 49 FastCat), oxygen sensor (SBE 43), fluorometer (ECO FLNTU-4050), ECO Triplet (ECO BBFL2-123), PAR (photosynthetically active radiation; Biospherical Instruments Inc. QCP-200L), and a synchronized video camera and xenon strobe (Davis et al., 2005). The VPR was towed at 10 knots (5.1 m s-1), undulating between depths as shallow as 5m and as deep as 120m approximately every 6 minutes. This provided a minimum horizontal resolution of 1.8 km throughout the tow.

Description of package contents within the "Data Files" and "Supplemetnal Files" sections:

VPR data presented in two types: images (tif format, *.tif) and log files for the hydrographic, bio-optical and navigation data (text format, *.combo). The images come in at 30 frames per second and the log files are 1 second averages. So there is not 1-to-1 mapping.

Each VPR tow (vpr1, vpr2, vpr3, etc.) has subdirectories called d### (year day #), then h## (hour), then the roi tifs collected during that hour and the ctd.dat file of corresponding physical data.

Example relative storage path within a tif image file zip:
RR2004/vpr/rois/vpr1/d362/h23/roi3.8594409700.tif
<cruise_id>/vpr/rois/d<year day #>/h<hour>/roiN.timestamp.tif

ROI naming convention is roiN.timestamp.tif where timestamp is milliseconds since midnight.
Tif file name example: roi0.4565601000.tif

N is the thread number in the processing stream, taking on values 0 through 3. This is a remnant from a prior incarnation of the software, not relevant to science use. Please ignore.

File name format: mmddhhminss.combo where mmddhhminss is VPR tow start date/time.

Data Processing Description

Calibrations:
* column numbers are relative to .combo files.

-------------
Column 11 fluorescence (ug / L)
TN376: fluo=6*((fluo/1000)-0.068); %SN FLNTURD-4050 Cal 2015-07-27
RR2004: fluo=6*(fluo/1000-0.073);%SN FLNTURTD-4050 Cal 2020-05-15
-------------
Column 12 PAR
light=sqrt(counts)*0.02;
-------------
Column 13 turbidity (NTU)
TN376: obs=2*(obs/1000-0.067); %SN FLNTURD-4050 Cal 2015-07-27
RR2004: obs=2*(obs/1000-0.069);%SN FLNTURTD-4050 Cal 2020-05-15
-------------
Column 18 Eco-triplet Bb
TN376: Bb=(lambda-66)*0.000007738;%TN376
RR2004 Bb=4.098e-06*(lambda-68);%SN BBFL2-123 Cal 2020-05-15
-------------
Column 20 Eco-triplet fluorescence
TN376: ecochl=(ecochl_counts-67)*0.0119;%%TN376
RR2004: ecochl=0.0109*(ecochl_counts-65);%SN BBFL2-123 Cal 2020-05-06
-------------
Column 22 Eco-triplet CDOM
TN376: cdom=(cdom_counts-61)*0.2207;%TN376
RR2004: cdom=0.1536*(cdom_counts-69);%SN BBFL2-123 Cal 2020-05-06

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Division of Ocean Sciences	OCE-1840381
NSF Division of Ocean Sciences	OCE-1736375

Deployments

Deployment	Synonyms	Start Date	Platform	Investigator
RR2004	SAMW	2020-12-26	R/V Roger Revelle	William M. Balch (Chief Scientist)	data info
TN376	SAMW	2020-01-25	R/V Thomas G. Thompson	William M. Balch (Chief Scientist)	data info

Instruments

Video Plankton Recorder

Supplied Name: Video Plankton Recorder II (VPR II, from SeaScan Inc.)

Supplied Description:

Environmental data (temperature, salinity, turbidity, fluorescence, irradiance, dissolved oxygen) collected by sensors mounted on the Video Plankton Recorder (VPR).

Instrument Type

Generic Name: Video Plankton Recorder

Acronym: VPR

Generic Description:

The Video Plankton Recorder (VPR) is a video-microscope system used for imaging plankton and other particulate matter in the size range from a few micrometers to several centimeters. The VPR is essentially an underwater microscope. It consists of four video cameras (with magnifying optics) synchronized at 60 fields per second (fps) to a red-filtered 80 W xenon strobe (pulse duration = 1 microsecond). The current lens on each camera can be adjusted to provide a field of view between 5 mm and 10 cm. Use of higher magnification lenses is currently being explored for viewing protozoans (less than 1 micrometer resolution). The four cameras are set for concentric viewing fields so that a range of up to four magnifications can be viewed simultaneously, allowing a wide size range of plankton to be sampled. Depth of field is adjusted by the lens aperture setting, and the volume sampled in each video field ranges from about 1 ml to 1 liter, depending on lens settings. The cameras have been configured for stereoscopic viewing as well.A strobe on the other arm illuminates the imaged volume and flashes 60 times per second, producing 60 images per second of the particles and plankton in the water. The images are then saved internally on a computer hard disk and later plotted.

Deployment: Most commonly, the VPR is mounted in a frame and lowered into the water from the stern of the ship. Sometimes, a CTD also is mounted next to the VPR to collect depth, temperature, and salinity information at the same time as each video image. The instrument is lowered down through the water to a maximum depth of 350 meters to generate a profile of plankton/particle abundance and taxon group along with temperature and salinity. In addition to the towed configuration for mapping plankton distributions, it is possible to deploy the VPR in a fixed position (on a mooring) for viewing plankton swimming behaviors in two or three dimensions. The VPR instrument system has been used in both configurations, and deployment on ROVs has been proposed.

This definition was taken from the WHOI Ocean Instruments Web site and from a US GLOBEC Newsletter.

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Dataset: VPR Data from TN376 and RR2004