chapter 4 observing platforms when planning an experiment, project, measurement, first think of the...
TRANSCRIPT
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….
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
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)
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)
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”
Tower in the Baltic Sea
http://www.bsh.de/en/Marine_data/Observations/MARNET_monitoring_network/Stationen/dars.jsp then go to “detailed drawing”
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,...
Diagnostic output
Vertical subductionHorizontal displacement
Line tension
Launch tension is another important factor, should not exceed 50% of breaking strength
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
Relevant links:
OceanSITESwww.oceansites.org
OOI project (NSF)http://oceanobservatories.org/infrastructure/
SeaCycler projecthttp://mooring.ucsd.edu/projects/seacycler/seacycler_intro.html
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
“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