Cruise inventory

RRS Challenger CH31

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS Challenger (74CH)
Cruise identifierCH31
Cruise period1988-06-26 — 1988-07-15
StatusCompleted
Port of departureBarry, United Kingdom
Port of returnPlymouth, United Kingdom
PurposeResearch
Objectives1. To deploy thermistor chain moorings on the Biscay abyssal plains to examine the propagation of internal tidal energy into the ocean interior from the continental slopes.
2. To examine the effects of mixing, nutrient availability and illumination of distribution of phytoplankton and zooplankton in the area of the slope.
3. To examine the scattering layer at the 300-400m depth contour near Chapel Bank over a tidal cycle.
4. To make CTD profiles over several tidal cycles in conjunction with the ADCP to examine mixing within the water column and to investigate turbid layers near the bottom. Draw samples from the rosette for Coulter counter analyses.
5. To investigate the diurnal fluorescence rhythm.
6. Recover longterm moorings in the Porcupine Sea Bight and deploy longterm moorings on the north slopes, to investigate slope transport.
7. To make continuous underway measurements of temperature, salinity, fluorescence, inorganic nitrate, reactive silicate, light transmission and surface illumination.
Chief scientistRobin D Pingree (Plymouth Marine Laboratory)
Cruise reportRRS Challenger CH31 cruise report ch31_88.pdf — access key 'C' (0.74 MB) 
Ocean/sea areas 
GeneralEnglish Channel
Bay of Biscay
SpecificBay of Biscay
Track chartsRRS Challenger CH31 cruise track — ch31_88track.pdf (00 MB) 
Measurements 
Physical oceanography 
Surface measurements underway (T,S)Quantity: track kilometres = 2000
Description: continous throughout the cruise.
Water bottle stationsQuantity: number of stations = 134
Description: S surface only
Transparency (eg transmissometer)Quantity: track kilometres = 2000
Optics (eg underwater light levels)Quantity: number of stations = 3
Description: extinction coefficient
Current metersQuantity: number of deployments = 22
Description: 22 deployed;10 days;4 long term in 9 month
Chemical oceanography 
NitrateQuantity: track kilometres = 2000
Biology and fisheries 
Primary productivityQuantity: number of stations = 3
Phytoplankton pigs (eg chlorophyll, fluorescence)Quantity: number of samples = 237
Description: chlorophyll a
PhytoplanktonQuantity: track kilometres = 2000
Description: fluorescence
ZooplanktonQuantity: number of stations = 18
Meteorology 
Incident radiationQuantity: track kilometres = 2000