St. Helena Phase 2 Site History
History Summary
| Station Name | St. Helena Phase 2 |
|---|---|
| Latitude | 15° 55.0' S |
| Longitude | 005° 43.0' W |
| Country | U.K. |
| Gloss No | 264 |
| Time Reference | GMT(00-23 hours) |
| Contributor | Proudman Oceanographic Laboratory, Joseph Proudman Building, 6 Brownlow Street, Liverpool, L3 5DA. U.K. |
| Observation Period | June 1993 - October 2001 |
| Instrument Type | B Gauge (Woodworth et al. 1996) |
| Site of Gauge | Jamestown Harbour, by the landing steps. |
Parameters recorded
| Period | CI(%) | Parameters | Sample Interval |
|---|---|---|---|
| 06 1993 - 09 1993 | 100 | ST,BT,AP,SL,SSP,HTP | 15 mins |
| 11 1993 - 02 1995 | 100 | ST,BT,AP,SL,SSP,HTP | 15 mins |
| 02 1995 - 10 1995 | 100 | ST,BT,AP,SL,SSP,HTP | 15 mins |
| 10 1995 - 10 1996 | 96 | ST,BT,AP,SL,SSP,HTP | 15 mins |
| 04 1997 - 12 1997 | 100 | ST,BT,AP,SL,SSP,HTP | 15 mins |
| 01 1998 - 07 1998 | 100 | ST,BT,AP,SL,SSP,HTP | 15 mins |
| 07 1998 - 06 2000 | 99 | ST,BT,AP,SL,SSP,HTP | 15 mins |
| 06 2000 - 10 2001 | 100 | ST,BT,AP,SL,SSP,HTP | 15 mins |
where:
- SL = ASLVTD01 = Sea Level
- ST = TEMPPR01 = Sea Temperature
- BT = CBTASS01 = Barometric Temperature
- AP = CAPHSL01 = Atmospheric Pressure
- SSP = PRSTPS01 = Sub Surface (total) Pressure
- HTP = PRSTPH01 = Halftide (total) Pressure
Reference Level
Sea level was recorded with respect to 'ST.HELENA B-DATUM JUNE 1993' until 1996, then with respect to 'ST.HELENA B-DATUM APRIL 1997'. The new datum is known relative to the old one through levelling, and is 18.0cm ABOVE it.
Quality Assessment
All data have been tidally analysed and constants and residuals checked. Records have been visually inspected for spikes, timing and datum shifts.
Possible datum shift (SSP and HTP) 04 Feb 1995 +20cm
Possible datum shift (SSP and HTP) 23 Oct 1995 -20cm
Possible datum shift (SSP, HTP and SL) 07 Apr 1997 -18cm (see comment on B-DATUM above)
| Period | Parameters | Comments |
|---|---|---|
| 06 1993 - 09 1993 | All | None |
| 11 1993 - 02 1995 | All | None |
| 02 1995 - 10 1995 | All | None |
| 10 1995 - 10 1996 | SSP HTP SL | Gap: (1996) 190-192,221-222 Gap: (1996) 190-192,221-222 Gap: (1996) 190-192,221-222 |
| 04 1997 - 12 1997 | All | None |
| 01 1998 - 07 1998 | All | None |
| 07 1998 - 06 2000 | SL SSP,HTP BT AP ST | Null values on (1999)007,059,114,322,362 Marked: (1999)007,059,114,322,362 Marked: (1998)241,364 (1999)007,059,114,322,362 Marked: (1998)317 (1999)007,059,114,322,362 Many spikes marked. Use with caution. |
| 06 2000 - 10 2001 | SL ST | Marked: (2000)183 (2001)155 Many spikes marked. |
Reference
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.
