PRE-OPERATIONAL MODELLING IN THE SEAS OF EUROPE
The PROMISE Project

Technical Annex 1.8

North Sea Project Data Set
 CD ROM quality controlled data from 15 monthly surveys Aug 1988-Oct 1989
Underway Surface Data:
 Salinity, temperature, fluorescence, SPM, irradiance, oxygen
Standard Stations Database:
 Bottle and CTD dips, approximately 100 stations each survey:
chlorophyll, phosphate, nitrate, nitrite, ammonia, silicate, SPM, temperature, salinity, oxygen, fluorescence, irradiance
Time series from moorings:
 currents, elevations, temperature, salinity
Time series from pre-operational models:
 currents


Technical Annex 1.10

Holderness Experiment
PI: David Prandle, Proudman Oceanographic Laboratory
 The Holderness coastline, some 30km of 20m high boulder clay cliffs is retreating at an average of 1.7m per year. The resulting yearly supply of one million cubic metres of sediment to the North Sea represents the largest single coastal source. The Holderness experiment aims to monitor this transport of sediments away from Holderness over the period October 1994 to January 1995 and to measure directly the component contributions to erosion, suspension and transport. This observational programme will be used to develop algorithms and test simulations in the subsequent model development phase. Thence, using detailed meteorological data available since 1960, simulated time sequences of coastal erosion and (subsequent) deposition will be compared with observational data on coastal retreat and accretion. Finally simulations will be made of the impact of both future and historical scenarios of climate change. Figure 1 illustrates aspects of the above programme in a simplistic summary of the many inter-connected components.

Observational Programme
 The monitoring programme co-ordinated by the POL involves 8 PMPs (POL monitoring platform) located on the seabed. Each PMP measures vertical profiles of current and suspended sediment using an ADCP (Acoustic Doppler Current Profiler) together with near-bed monitoring of: i. turbulence and surface wave currents by an S4 electromagnetic current meter, ii. suspended sediment concentration by an optical transmissometer (UCNW) and

iii. water level (tide, surge and surface wave components), temperature and conductivity. These platforms were designed to mount a variety of autonomous instruments within a protective, stable and recoverable(!) housing - a 100% return record was achieved in 12 monthly deployments in the Dover Strait. The suitability of their design for Holderness was tested to the limit within a day of first deployment in November 1993 when winds up to 80 knots occurred.

The two lines of 3 PMPs off the Holderness coast measure long-shore and cross-shore gradients out from the wave-dominated near-shore region to the deeper tidal current dominated offshore region. An offshore PMP to the north-east provides boundary condition data on open-sea conditions. A PMP moored at the mouth of the Humber estuary provides both a link between erosion from Holderness and conditions in the estuary and serves directly as a boundary condition for estuary models.

The POL co-ordinated the deployment of: i. the OSCR H.F. Radar system measuring surface currents up to 20kms offshore, ii. an X-band radar measuring directional wave spectra up to 2kms offshore, iii. a directional wave buoy and meteorological buoy, iv. a cross-shore array of bottom-mounted pressure sensors measuring surface waves and 'medium-frequency' waves. Additional wave data will be obtained from analysis of the H.F. Radar back-scattered spectra (University of Sheffield). This unique concentration of surface wave measurements by an

array of instruments will be made available as a discrete data set for development of wave-propagation models worldwide. (Production of fine-scale bathymetric data of the associated region has been specially commissioned to maximise the usefulness of this data set.)

More specialised instrumentation (BLISS) for measuring near-bed dynamical and sedimentary processes will be deployed by UCNW (University College of North Wales) and University of Plymouth at four near-shore locations alongside one of the PMP sections. Similar equipment (Minipods) will be deployed alongside the other PMP section by MAFF (Lowestoft) as part of their involvement in the COSEDS programme. This COSEDS group will also deploy the specialist multi-instrument platforms Quadrapod & Tetrapod at the deeper water end of a PMP section. In the deeper water of the other PMP section, POL will deploy the STABLE rig to make similar recordings of the near-bed sedimentary regime.

This array of moorings will be supplemented by CTD profiles and water bottle samples taken from RRS Challenger during the October 1994 and January 1995 cruises. These 'calibration' exercises will extend over a tidal period close to both spring and neap tides at each PMP site. Challenger will also complete a wider-area quasi-synoptic survey at the beginning and end of each cruise to provide 'initial conditions and validation data' for model simulations. For the moorings closest to the beach trawlers will be used to make similar measurements.


Task (synthesise and disseminate observed data)/Deliverables
Provide data sets:
 October 1994-March 1995
1.10.1 Wind:
 off-shore meteorological buoy, observed land-based stations,
observed UK Meteorological Model
1.10.2 Waves:
 2 directional, 1 (non-directional) wave buoys, 6 bottom pressure cells,
2 bottom current meters (sampling at 1Hz), X-band radar, OSCR H.F. Radar
1.10.3 Currents:
 6 ADCP moorings, 6 S4 current meters, OSCR H.F. Radar
1.10.4 Suspended sediment:
 6 transmissometers, 2 OBS, 2 ABS
1.10.5 Remote sensing:
 SAR Imagery, CASI

Last updated: 10th May 1996. Please send comments to A.Lane@pol.ac.uk