Cruise inventory

RV Prince Madog PD39/09

Cruise summary report

Cruise Info. 
Ship name (ship code)RV Prince Madog (74P2)
Cruise identifierPD39/09
Cruise period2009-09-22 — 2009-09-24
Port of departureMenai Bridge, United Kingdom
Port of returnMenai Bridge, United Kingdom

1. 50 hour time series of microstructure measurements using the VMP profiler next to mooring site in the seasonally stratified part of the Western Irish Sea.
2. CTD profiles and water samples for chemical analysis.
3. Retrieval of ADCP and thermistor moorings
4. A short series (5) Lowered ADCP profiles to test different structure-function configurations


The cruise was initially set to depart at 1000 BST on the 21/09/2009, but was delayed until 1300 BST on the 22/09/2009 due to the forecast for stormy weather. Once we did arrive on station the microstructure time-series measurements and associated CTD/bottle profiles (every 6 hours) commenced without further delay at approximately 2005 BST, 22/09/2009.

Only one of the two moorings retained the surface buoy it was deployed with - this was the U-shaped mooring with solar panels, thermistors and mid-water ADCP, and had been observed with an overturned surface buoy a month earlier by the Macoma crew. The decision was taken to drag for the second L-shaped mooring with the bottom-mounted ADCP on the Thursday lunchtime (24/09/2009) in order to accommodate manpower requirements. The microstructure time-series was truncated at 36 hrs (0900 BST, 24/9/09) for this purpose.

The dragging operation was successful, with the buoy-less L-shaped mooring found on the opposite side of the buoyed-up mooring to Danny Buoy (Northern Ireland Fisheries mooring). Both moorings were successfully recovered.

Two issues with the mooring instruments caused loss of data:
1. 300KHz ADCP was covered in silt upon recovery, but still pinging. Recovered data show that the ADCP was turned upside down at the end of August, so we are missing useable data from the last 3 weeks of deployment.
2. An attempt was made to attach a new anemometer to the met-buoy at the end of August. Unfortunately the surface buoy was found overturned and the power supply box flooded. The surface buoy was righted at the time, but there were not the resources available to replace the power source and the new anemometer was not deployed. Therefore, no moored data was available for the entire 2009 field season.

Issues relating to chemical water samples being taken from the CTD:
1. No food was stored in the lab fridge/freezer this time, so there was no problems disrupted experiments.

Test structure-function L-ADCP casts were made on three occasions:
1. 1 profile during the time-series
2. 3 profiles between the end of the microstructure time-series andthe mooring recovery operations
3. 2 more profiles north of Holyhead, in 80 m water, on route to Menai Bridge following the mooring recovery.
Chief scientistYueng-Djern Lenn (Bangor University School of Ocean Sciences)
Cruise reportRV Prince Madog PD39/09 cruise report pd39_09.pdf — access key 'C' (0.02 MB) 
Ocean/sea areas 
GeneralIrish Sea and St. George's Channel
SpecificWestern Irish Sea