RRS Challenger CH18
Cruise summary report
| Cruise Info. | |
| Ship name (ship code) | RRS Challenger (74CH) |
| Cruise identifier | CH18 |
| Cruise period | 1987-09-02 — 1987-09-25 |
| Status | Completed |
| Port of departure | Barry, United Kingdom |
| Port of return | Barry, United Kingdom |
| Purpose | Research |
| Objectives | 1. To recover current meter moorings 108 and 109 deployed on Frederick Russell Cruise 2/87.
2. To deploy 2 short term current meter and thermistor chain rigs in the region of strong tidal flow on the continental slopes south of Chapel Bank to examine the production and generation of internal tides. These moorings (rigs 110 and 111) are to be deployed in depths of 2500m and 1000m and to be instrumented over most of the water column. 3. To deploy four long term current meter rigs in the Porcupine Sea Bight. These moorings (112, 113, 114, 115) are to be recovered on Challenger Cruise 31/88. 4. To make repeated runs with the Sea Soar, thermistor span and side-scan both at spring tides and neap tides to investigate internal wave proportion and near surface mixing. 5. To make CTD yoyos over a tidal cycle in the upper slope region and at increasing distances from the slopes. These are to be made in conjunction with the ADCP and the transmissometer to investigate mixing within the water column and the production of turbid layers near the bottom. Samples are to be drawn for inorganic nutrients, freon and Coulter Counter analyses. 6. To continously measure the surface values of temperature, salinity, fluorescence, light transmissions, inorganic nitrate, reactive silicate and to obtain samples for particle size, phytoplankton and zooplankton analyses. 7. To deploy these satellite tracked drifting buoys in the Porcupine Sea Bight. |
| Chief scientist | Robin D Pingree (Marine Biological Association of the UK) |
| Cruise report |  (0.32 MB) |
| Ocean/sea areas | |
| General | English Channel Bay of Biscay |
| Specific | North Atlantic |
| Track charts |  |
| Measurements | |
| Physical oceanography | |
| Surface measurements underway (T,S) | Quantity: track kilometres = 3333 |
| Water bottle stations | Quantity: number of stations = 118 Description: surface only |
| CTD stations | Quantity: number of stations = 251 |
| Subsurface temperature and salinity measurements | Quantity: track kilometres = 444.48 Description: seasoar 0-150m |
| Subsurface temperature measurements | Quantity: track kilometres = 148.16 Description: Thermistor Span 0-10m |
| Transparency (eg transmissometer) | Quantity: track kilometres = 3333.6 |
| Current meters | Quantity: number of deployments = 17 Description: 20 deployed;15 days |
| Chemical oceanography | |
| Nitrate | Quantity: track kilometres = 3333.6 |
| Biology and fisheries | |
| Phytoplankton | Quantity: track kilometres = 3333.6 |
