BODC FIXED STATION DOCUMENT NO. 64181 Site History : Dakar-B, Senegal =============================== Station name : Dakar-B Latitude: 14 40.0N Country : Senegal Longitude: 017 25.8W GLOSS No. : 253 Time Reference: GMT (hours 00-23) Contributor : 1983-1985 TOGA Sea Level Center Instrument type : Aanderaa WLR5 (bottom-mounted pressure gauge) Site Gauge : Observational periods: 1982 - 1989 Reference Level: Due to the nature of the bottom-mounted pressure gauges, no link could be established between the zero of the gauge values and fixed points on land. Also, tide staff observations or the like were unavailable. This series has no long-term reference level. Quality Assessment by the UH Sea Level Center: Comment: Although this data set is within the sea level archive, the user must acknowledge that these data represent inferred sea level from a sub-surface pressure gauge, which measures the combined weight of the column of water and air above it. A constant atmospheric pressure has been subtracted, but variations in atmospheric pressure, which would not be sensed by a conventional float/ well gauge, would affect the measurement of the sub-surface pressure gauge. Techniques of data processing by the originator are discussed in the second reference below. The depth of the instrument in the water was about 8 m. The Dakar pressure gauge records consist of four separate segments Dakar-A: 24 Dec 1982 - 12 Dec 1983 Dakar-B: 12 Dec 1983 - 09 Jan 1985 Dakar-C: 30 May 1986 - 16 Dec 1986 Dakar-D: 16 Dec 1986 - 24 May 1989 The series was broken into segments because level jumps could be identified at the time of instrument replacements. Due to the tendency for pressure gauge sensors to drift, it is beneficial for investigators to know the time span of each instrument deployment (time/date as yyyy/mm/dd/hh(GMT)): Series start stop Dakar-A 1982/12/24/13 - 1983/01/25/10 Dakar-A 1983/01/25/12 - 1983/03/17/15 Dakar-A 1983/03/17/17 - 1983/05/16/10 Dakar-A 1983/05/16/11 - 1983/07/20/10 Dakar-A 1983/07/20/11 - 1983/12/12/10 Dakar-B 1983/12/12/11 - 1984/04/30/11 Dakar-B 1984/04/30/12 - 1984/10/04/11 Dakar-B 1984/10/04/12 - 1985/01/09/12 Dakar-C 1986/05/30/15 - 1986/12/16/15 Dakar-D 1986/12/16/23 - 1988/09/21/01 Dakar-D 1988/11/11/10 - 1989/05/24/10 For more information: Verstraete, J.M., 1988. Sea level variations in the tropical Atlantic. Time series of ocean measurements, Technical series, UNESCO,4,33-47. Verstraete, J.M., 1992. Accuracy of shallow pressure gauges. Joint IAPSO-IOC Workshop on Sea Level Measurements and Quality Control, Paris, 12-13 October, 1992. IOC Workshop Report No. 81, UNESCO. pp. 70-76. CI MISSING REPLACED GAPS QUESTIONABLE YEAR (%) DATA OR BAD DATA FLUCTUATIONS ---- --- -------------------- --------------- -------------------- 1983 6 none none none 1984 100 none none none 1985 3 none none none