BODC FIXED STATION DOCUMENT NO. 62232 Site History: Tristan da Cunha, Phase 1 ======================================== Station Name : Tristan da Cunha Latitude : 37 03.0S Country : U.K. Longitude : 012 18.0W Gloss No : 266 Time Reference : GMT(00-23 hours) Contributor : Proudman Oceanographic Laboratory Bidston Observatory Prenton CH43 7RA. U.K. Observation Period : Oct 1984 - Dec 1998 (Site has not been visited to download data since Jan 1999) Instrument Type : Oct 1984 - Oct 1986 Aanderaa bubbler Oct 1986 - Dec 1992 Digiquartz pressure sensor with telexed data transmission. (see note below) Jan 1993 - Dec 1997 B-type Gauge as described in Ref 1. Site of Gauge : Tristan da Cunha Harbour. Ref 1: Woodworth, P.L., Vassie, J.M., Spencer, R. and Smith, D.E. 1996. Precise datum control for pressure tide gauges. Marine Geodesy, 19(1), 1-20. Parameters recorded : Period Parameters Sample Interval ================= ====================== =============== 10 1984 - 11 1985 AP,SP 60 mins 11 1985 - 05 1986 SP 30 mins 06 1986 - 10 1986 AP,TP 30 mins 10 1986 - 10 1987 ST,AP,TP,SSP 15 mins 10 1987 - 10 1988 ST,AP,TP,SSP 15 mins 10 1988 - 02 1989 ST,AP,TP,SSP 60 mins 02 1989 - 02 1990 ST,AP,TP,SSP 15 mins 02 1990 - 10 1990 ST,AP,TP,SSP 15 mins 10 1990 - 01 1992 ST,AP,TP,SSP 60 mins 01 1992 - 12 1992 ST,AP,TP,SSP 15 mins 01 1993 - 02 1994 ST,SSP,HTP,SSP 7.5 mins 02 1994 - 02 1995 ST,AP,SP,SSP,SSP 15 mins 02 1995 - 01 1996 ST,AP,LT,SSP,HTP 15 mins 01 1996 - 12 1997 ST,AP,LT,SP,SSP,HTP 15 mins 01 1998 - 12 1998 ST,AP,LT,SSP,HTP 15 mins where ST = TEMPPR01 = Sea Temperature, LT = CTLGPR01 = Data Logger Ambient Temperature, SP = PRESPS01 = Sea Pressure, AP = CAPHSL01 = Atmospheric Pressure, SSP = PRSTPS01 or PRSTPS02 = Sub Surface (total) Pressure, TP = PPSSRL01 = Total sub surface pressure - 1000.0 and HTP = PRSTPH01 Half Tide (total) Pressure. Completeness Index : 1998 16.7%, 1985 98.6%, 1986 87.0%, 1987 99.5% 1988 80.1%, 1989 88.5%, 1990 99.5%, 1991 98.9% 1992 93.7%, 1993 92.1%, 1994 98.6%, 1995 99.9% 1996 100%, 1997 99.5% 1998 97.8% Datum Information : Not available Quality Assessment : All data have been tidally analysed and constants and residuals checked. Records have been visually inspected for spikes and timing shifts. Timing and residuals appear satisfactory. However due to instrumentation drift, datum problems etc the contributor recommends, that these data should only be used for surges and short term variability and not for long term sea level studies. PLEASE NOTE: (For data: Oct 1986 - Dec 1992) Datums for telexed transmitted data and logger recorded data, for the same period, differ. Telex transmitted data is 0.15 db higher than logger recorded data, the latter is assumed to be correct. Where files consist of a combination of both, telexed and logger recorded data, datum shifts are observed. PERIOD PARA COMMENTS ================= ==== ============================================= 10 1984 - 11 1985 AP Gap: (1984)305 - (1985)001,(1985)215 - 323 SP Datum Shift: 02 May 1985 0700 hrs -0.2 dbars Datum Shift: 04 May 1985 0900 hrs +0.2 dbars Questionable Fluctuations: None 11 1985 - 05 1986 SP Gap: None Marked: (1986) 044,065,108,115 Questionable Fluctuations: None 06 1986 - 10 1986 AP Gap: (1986)180 - 273 SP Gap: (1986)283 - 284 Questionable Fluctuations: None 10 1986 - 10 1987 AP Gap: (1987)270 - 278 TP Datum Shift: (1987) 270 see note above Datum Shift: (1987) 278 see note above Questionable Fluctuations: None 10 1987 - 10 1988 AP Gap: (1988) 104 - 293 TP Datum Shift: (1987) 104 see note above Questionable Fluctuations: None 10 1988 - 02 1989 AP Gap: (1988) 293, 314 - (1989) 039 ST Gap: (1988) 293, 314 - (1989) 039 TP Datum shift: (1988) 314 see note above Questionable Fluctuations: None 02 1989 - 02 1990 AP Gap: (1990) 038 Questionable Fluctuations: None 02 1990 - 10 1990 All Gaps: None Questionable Fluctuations: None 10 1990 - 01 1992 AP Gap: (1991) 115-120,266-274,274-275 ST Gap: (1991) 115-120,266-274,274-275 TP Gap: (1991) 115-120,266-274,274-275 Questionable Fluctuations: None 01 1992 - 12 1992 All Datum shift: (1992) 012 see note above ST Marked: (1992) 94-95,160,161-162,170, 174,175-176,177,289,332 Questionable Fluctuations: None 01 1993 - 02 1994 SSP PRSTPS02 - Gap: (1993)099 - (1994)034 HTP Gap: (1993)099 - (1994)034 ST Gap: (1993)099 - (1994)034 SSP PRSTPS01 - None All Marked: None Questionable Fluctuations: None 02 1994 - 02 1995 All Gaps: None Marked: None Questionable Fluctuations: None 02 1995 - 01 1996 SSP Gap: (1995)054 - (1995)055 HTP Gap: (1995)054 - (1995)055 ST Gap: (1995)054 - (1995)055 01 1996 - 12 1997 All Gaps: None Marked: None Questionable Fluctuations: None 01 1998 - 12 1998 SSP Marked: (1998) 010,154-362 Questionable Fluctuations: 138-139 HTP Marked: (1998) 119-362 Half tide sensor does not always record the top of the tide. ST Marked: (1998) 119,128-362 AP,LT Gaps: None Marked: None Questionable Fluctuations: None