UNESCO SCIENCE SECTOR - MISSION REPORT
1. Name: Hester VIOLA.
2. Division/Unit/Office: SC/IOC/Toulouse.
3. Dates of Mission: 9th– 16th May 2009
4. Countries visited:
San Diego, USA
5. Institutions visited/Personalities met :
- Scripps Institution of Oceanography, La jolla
6. Purpose of Mission: Attendance at the DBCP Wave Pilot Project (WET/WMD) steering team meetings and side meeting with
OceanSITES members, La Jolla, USA 11-15 May 2009.
7. Main results:
Attended the meeting of the DBCP Wave Pilot Project (WET/WMD) steering teams
Visited Pacific Gyre workshop.
Discussed OceanSITES data management tasks with Matthias Lankhorst, SCRIPPS, and Project Office
tasks with the co-chair, Uwe Send.
8. Actions required and follow-up (by Hester Viola):
- JCOMMOPS maps need to show all moorings measuring waves and sending data onto the GTS
- FM65 Contact Meteo France about including WAVEOB messages in the statistics for JCOMMOPS.
Programs: e.g. European Platforms. Poseidon, GR 3 wavescan, Italy. Australian. Spanish buoys (directional
wave).
- Contact JMA about wave measurements to ask if someone can participate in the WMD project or provide
recent information.
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Notes
- Differences in hull design, payload, mooring, sampling frequency and period, processing (frequency bands and
cut-offs) etc
- Importance for Wave hindcasting & forecasting, development of climatologies, workshop session at Wave
Hindcasting and Forecasting
- FM65 Australian. – Spanish buoys (directional wave). Contact Meteo France. Poseidon, GR 3 wavescan, Italy.
- PIRATA Waves? TAO budget won’t cater for that or RAMA probably.
Bob Jensen
1970 – short term experiments for NWS. USACE with directional wave (CDIP-SIO)
IOOS wants all directional wave measurements (NOMAD wave or mooring plus co-located wave measurement)
First 5 needed with small signal to noise ratio - ,
Jon Turton
Working closely with Modellers. First-3 from TRIAXYS.
Canada - Norway
Datawell buoys to be used in validation (directional). 100k. NOMAD still used on East Coast – 3m buoys are
surviving harsh conditions – bigger (more expensive) ship needed to deploy. No interest in directional waves.
Intercomparison reports – Technical Report – synthesize alot of information for someone generally in terested in
tests etc. Genreal comparison of sensors and Network approaches. NOMAD, 3m, DISCUS, DATAWELL,
TRIAXYS, WAVERIDER,
ADCP, AWiPS – do measure waves.
Metadata
FGDC compliant XML for the metadata summary
Metadata :
Sensor Level metadata Operational systems (sampling periods)
Wave Comparison metadata –
Hull type and material (Aluminium, foam)
Mooring
Load (bridle type)
Communications system
What kind of filtering applied?
Schematic/Drawings of platform?
IODE Manual 26 (could input to update the requirements).
Remote sensing metadata needs may be helpful to define what’s required.
New Platforms and approaches
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Capability to measure waves on platforms that don’t have that right now and are not feasible in the current form.
Conventional approaches won’t work if the mooring is not designed to follow the waves. Top moored or not
wave following.
Moor a second mooring (wave rider) – but distance issue, unsafe. Costly.
Nortec (AWAC/P) testing in the Atlantic
Challenge:- manufacturers need to come up with ideas.
Upward looking ADCP – tethering to the bottom of an OceanSITES platform
PUV sensor from the bottom of a sub-surface mooring. Need relatively inexpensive way to provide directional
information (eliminating the motioni of the sensor which is not part of the wave movement)
Want directional capability. If a taut mooring wire, then can’t follow waves. Drifters to measure 1d spectra.
DM - Measure response of platform to the waves and use PUV as well – take out the movement of the platform
from the PUV/ADCP data. Most direct measurement.
Easier to measure and eliminate if you measure the platform movement 6 dimensional movement measures
possible.
– rather than trying to understand the mooring line behaviour – 100m below the mooring bridle. If 10m down
then you won’t get the tilting movement modelled.
NDBC some buoys measuring directional waves and currents simultaneously - but should have dedicated
research buoy not using existing operational ones.
Ideallly need a standalone package – to measure buoy movement , subtract PUV measures and then get waves as
a result.
How to engage with Manufacturers – Scripps could come up with the platforms to test from. PhD topic.
** Jean Bidlot – to review the Waveob -> BUFR translation and to review the BUFR Buoy template for use of
Directional Wave data.
Preference is to measure wave number spectrum rather that frequency/direction spectrum (as that is measured by
satellite).
** cwp Vision Map – SAR and Altimeter ~1DEGREE wide swath. 50 drifters randomly across oceans. Near
Polar orbit 10degrees from North.
13/05/2009
Attended the meeting of the DBCP Pilot Project for Wave Measurements from Drifting Buoys
Deep ocean wave measurements needed for validation of models and satellite obs, process studies (e.g.
hurricanes)
Undrogued drifter could be a good wave follower with GPS, or upward looking ADCP.
Should have energy spectrum + first four spectral moments. (act-us.info
Need to have x,y,z or their derivatives (attitude determination). No buoy is a perfect wave follower. Compensate
for the buoys inertia (only acceptable if undrogued) Buoy motion + PUV or with ADCP.
Submergence is almost zero once drogue lost. (Pac Gyre has a test case with Iridium high res. data which passed
by the NOAA moorings)
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Cost of the hardware varies – best example is 3000usd.
30 second ephemeris message (lasts 4 hours) 4 sats for 3d + user clock error.
Adopt Scripps methods for validation against a standard.
Japan – wave buoy using GPS
Datawell buoy DWR-G 40cm or 90 cm. 30-60k.GPS only and Inertial.
CCD continental control design. GPS for 2D spectra. DUCK array tests.
PN - JCOMM doesn’t define any requirement for ocean current measurement GCOS does.
FGGE low level pressure. Either without drogues or drogues were falling off.
First step needs to be subset of undrogued drifters. If standalone system –would have a different shape cross t tilt
with waves no heave period, but will have a pendulum period. Code drifters – SIO. Spherical buoys transfer
function is simpler. W,U and V can be resolved.
Cannot measure breaking waves, only linear period.
But in the long term need to find a way to either upgrade existing standard drifters or make a package to attach
somehow to a subset to be useful once drogue falls off. Perhaps a damper is needed with a weight to make the
sphere a non-linear oscillator. (will have a pendulum period, but won’t have an oscillator period)
Buoy does stay vertical – especially with a wind vane on top.
Office Naval Research - Miniature Wave Buoy – CCD. Significant wave height doesn’t allow to do
intercomparison. Wind waves (higher frequency) are produced when wind picks up or changes. GPS oscillators
are sensitive to temperature – so high levels of wave energy measured but in fact was due to heating of the
sensor. Measuring different periods, 9-band energy (cm2) and direction (deg). Hs (m), Tp (s), Dp (deg) and Ta
(s).
Drop outs on GPS in high seas.
Action plan
** Contact Japan about Wave Buoys and manufacturers
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