Chapter 4 Observing platforms

When planning an experiment, project, measurement, first think of the requirements/needs you have !

Not enough to say „I want to measure currents in a such and such a location“.

The platform is usually dictated by a variety of needs and the respective capabilities and cost !

Have to consider:• Cost • range (horizontal and vertical)• endurance (time, power, storage)• payload• real-time capability• sampling resolution in space/time• power availability

typical requirements shown in following….

a: Reaching remote ocean regions

b: Useage of heavy equipment

c: Taking of samples

d1: Measurements in the deep ocean

d2: Measurements at the seafloord3: Measurements at the sea surface

are actually very tricky..... and require special efforts/techniques

Shipheave

wave motion

Minimum depth to first measurement 5-10m

Safety distance from bottom 10-20m (weight with alarm or acoustic pinger)

Near-surface and near-bottom CTD data missing or extrapolated !!!

Installation depth plus blank-out region plus first 1-2 bins not useable (3-10m)

Last 10% of profile before bottom (or surface) reflection not useable due to sidelobe reflections (see ADCP chapter)

ADCP‘s (acoustic doppler current profilers), vessel or buoy or bottom-mounted, also miss surface and bottom

e: Measurements of (vertical) profiles

CTD profileFree-fall current profile

f: Continuous observations (timeseries)

(Takahashi et al 1995)

Net CO2 flux

g: Large-scale coverage

Remote sensing of surface Remote sensing of surface Remote sensing of surface

h1: Remote sensing of the sea surface (for better coverage or because of inaccessability)

h2: Remote sensing of the interior (for better coverage or because of inaccessability)

i: Stable platforms (no or little motion)

j: High accuracy (versus cheap, expendable, large numbers…)

k: Data telemetry

l: Following of water masses

Research vessels

Things to consider when planning useage of a research vessel:

• availability of ship• size (capable to reach location, do the work, not too big)• equipment - cranes, winches - echo sounders, ADCP, pingers, - navigation, communication systems, - installation of own equipment like pingers, - power connections)• positioning system• weather and ice limitations• deck space, container spaces (above and below deck)• weight of equipment (on and below deck) • lab space• cost• speed• safety restrictions (hazardous chemicals and procedures)• ability to work at night• does work need to be done over stern/side/from bow, etc.

US vessels:www.unols.org

SIO vessels:http://shipsked.ucsd.edu

French vessels:http://www.ifremer.fr/fleet/

German vessels (partially in German):www.ifm.zmaw.de/leitstelle/ www.briese.de/forschungsschifffahrt-briese.html?&L=1 www.awi.de/en/infrastructure/ships/

Atalante „live“ (German and French):http://www.ifremer.fr/move/

Typical research vessel costs:

Sproul: $12,000 /day

New Horizon: $22,000 /day

Melville, Meteor, Atalante: $35,000 /day

Polarstern $50.000 /day

Student funding is available for shiptime,and has the highest priority with UC ship funds.Sproul and New Horizon have frequent holes inthe schedules.

Ship (hydrographic data) from

http://cchdo.ucsd.edu/

(actual data plots/sections can be found athttp://sam.ucsd.edu/vertical_sections/.index.html )

Volunteer Observing Ships (VOS) orShips Of Opportunity (SOO)

Commercial ships (ferries, container vessels, etc) which carry out various observations on the way, or deploy probes/instruments

Main requirement:- must be able to do this at full speed- should take minimum effort/attendance by crew- modifications to ship should be small

Advantages:- Cheap- frequent trans-basin coverages

Disadvantages:- startup effort is large- limited sensors- speed- ships may be moved

Thermosalinograph:

Problem: calibration needs taking samples and analyzing them (i.e. shipping them maybe from distant ports)

Many other variables can be analyzed from engine intake water, example „Ferrybox project“:

Sampled on some lines:

water temperature, salinity, turbidity, dissolved oxygen, fluorescence, ammonium, nitrate/nitrite, phosphate, silicate,

different algae groups

Project which coordinated many European lines and institutions finished in 2006. Now have to go to single country websites to get data and plot….

www.gkss.de/institute/coastal_research/structure/operational_systems/KOI/projects/ferrybox/001919/index_0001919.html

http://ferrydata.gkss.de

XBT temperature probes launched from VOS

Hi-resolution XBT network

Biases due to manufacturing changes and fall-rate issues are still an active and hot discussion/research topic…Sensor good to 0.05C but fallrate random error can give 0.1-0.2C, and fall-rate biases can be the same (that needs to be resolved)

ADCP observations from VOS:

Oleander ADCP sections across the Gulf Stream:www.po.gso.uri.edu/rafos/research/ole/index.html

Nuka Arctica ADCP sections 1999-2002 (mean)

Underway CO2 observing network

www.ioccp.org/ then go to Underway CO2

Continuous Plankton Recorder (CPR)

www.sahfos.ac.uk/about-us/cpr-survey/the-cpr-survey.aspx

Underway data project offices / data centers:

www.jcommops.org/soopip/

www.coriolis.eu.org/Data-Services-Products/View-Download tthere go to “data selection” and after selection “refresh”

Observation towers

www.whoi.edu/science/AOPE/dept/CBLAST/ASIT.html

Tower in the Baltic Sea

http://www.bsh.de/en/Marine_data/Observations/MARNET_monitoring_network/Stationen/dars.jsp then go to “detailed drawing”

SPAR buoys

www.mpl.ucsd.edu/resources/flip.intro.html

Moorings

Mooring technologies

Available now or in near future: surface and subsurface moorings, winched systems, cabled moorings, high-latitude spar buoys, virtual moorings, under-ice moorings,...

Animation of a typical subsurface mooring

Mooring design (subsurface)

depth component S/N rope# distance incl. &length from stretch lower end

Residual buoyancy (kg)

Modelling of mooring subduction

Mooring shape model fitted to some pressure data

Diagnostic output

Vertical subductionHorizontal displacement

Line tension

Launch tension is another important factor, should not exceed 50% of breaking strength

Loading/packing list generated

Typical component costs…

Wire termination: $125-150

Anchor  $1000 

glass balls  $450 ea. 

foam floats:          45" - $14,000          49" - $16,000           51" - $23,000          57" - $29,000          62" - $35,000          76" - $46,000

Example cost for 100m mooring

See also movies of SeaCycler spinning in lab….

Relevant links:

OceanSITESwww.oceansites.org

OOI project (NSF)http://oceanobservatories.org/infrastructure/

SeaCycler projecthttp://mooring.ucsd.edu/projects/seacycler/seacycler_intro.html

Some ongoing moorings….

Possible, cost-effective configuration....

Developed and deployed 2 moorings with full inductive capability, controller and acoustic modem each.

quarterly sampling misses much variability and events moorings are an ideal (and necessary) complement

moored sensors NEED ship samples for calibration/ground truth, e.g inorganic carbon, net tows with EK60 for moored sonar

all moorings are open and flexible and real-time; collaborations and partnerships are sought

CCE-2 and Del Mar currently unfunded, need endorsements, expressions of support, especially for critical SWFSC/Demer component

O2/Chl, pH/CO2

O2, Chl 35m

T/S, O2 90m

Del Mar mooring on shelf since 2006, CalCOFI line 93

More cool things at http://mooring.ucsd.edu/projects/delmar

oxygen at 35m

Geodetic mooring systemto observe seafloor motion with cm-accuracy

“Often the physical and chemical measurements needed to link ecosystem variability to environmental variability do not exist.”(OceanObs09 Community Statement)

Showcase ???

CCE-1 co-funded by unique NOAA climate&NMFS sharing (S.Murawski/M.Johnson)

- NOAA climate with NOAA NMFS- SIO with NOAA SWFSC and NOAA PMEL

- Send & Ohman with Demer, Sabine, Dickson, Hildebrand, Martz

meteor., 7-ch radiationpCO2, T/S pH, O2

ADCP

T/S, Chl-aturbidity

T/S, Chl-aNO3, turbidity pH, O2

T/S7-ch radiation

acoust.zooplankt

passive mammal

0m

0-500m

20m

40m

80m

0-300m

1000m

CCE-1

Many sensors, collaborators, institutions (CCE-1)

real-time in

du

ctive telem

etry an

d c

on

trol

Powerful and compelling due to its unique setting within CalCOFI and LTER

California Current Ecosystem (CCE) moorings

Pt.Conception

Gliders (CORC,LTER, Moore)

CalCOFI/LTER

CCE-1 (SIO/SWFSC/PMEL)

CCE-2

Complementary with ship surveys and glider sections

- Ships sample many variables and provide ground truth- Gliders provide cross-shelf sampling with a few variables- Moorings give full time sampling, wide range of variables

CalCOFI line 80