QUALITY ASSESSMENT OF SEA LEVEL DATA by the UH SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER JOINT ARCHIVE FOR SEA LEVEL updated: 30 Oct 2000 Station : Booby Island Latitude: 10 36.0S Country : Australia Longitude: 141 55.0E JASL # : 336A Time Meridian: 150E (GMT + 10 hr) GLOSS # : 061 TOGA #: P025 NODC #: 31140101 Contributor : The National Tidal Facility Flinders University of South Australia GPO Box 2100 Adelaide, 5001, South Australia AUSTRALIA Originator : same Original Data: analog Instrmnt Type: Leupold & Stevens (L&S) float/stilling well (1988- 08/May/1991); Mace gauge 08/May/1991-18/Dec/1991; L&S gauge 18/Dec/1991-13/Feb/1992; Mace gauge 7/Apr/1992 onward Digitzd Intvl: unconfirmed Present Data : Hourly, daily, and monthly values obtained by: Hourly : unconfirmed Daily : 119-point convolution filter (Bloomfield, 1976) centered on noon applied to the hourly data with respective periods of the 95, 50, and 5% amplitude points at 124.0, 60.2, and 40.2 hours Monthly: Simple average of all daily values; calculated if 7 or fewer days are missing Span of data : 01 Jan 1988 - 31 Dec 1999 Gaps > 1 mon : 15 Jun 1989 - 06 Aug 1989;13 Feb 1992 - 07 Apr 1992 16 Apr 1993 - 23 May 1993;01 Mar 1995 - 17 Apr 1995 14 Apr 1997 - 29 Jul 1997;01 Jan 1998 - 30 Apr 1998 12 Oct 1998 - 15 Jan 1999 Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 Units : millimeters Missing Data Flag : 9999 Existing : Yes Operational : Yes Sat. Trans. : No Distribution : 1988-1999 Refernce Levl: The sea level heights are referred to the zero point assigned to the tide staff. Benchmark information is available upon request from the contributors. The primary Tide Gauge Benchmark is "NMV/B/458", "RAN BM A", at the top of an iron stake driven into the rock and standing about .23m high on the NW side of Booby Island about 6m N of the tide gauge hut. Comment : The residuals (observed data minus predicted tides) are very noisy, probably due to shallow water and complex coastal geometry effects that are not resolved by the harmonic analysis. The hourly data may also contain periods with timing errors which are not offset by increments of one hour; however, these periods are not identifiable due to the large fluctuations in the residuals from the unresolved harmonic analysis. The period Feb-Mar 1991 shows phase drift in the timing. Otherwise, the daily and monthly values are reasonable and do not reveal any obvious reference level shifts. The tidal and annual variations are extremely larger than the nearest station, Port Moresby. SPECIAL NOTE FROM THE DATA CONTRIBUTORS: Supply of sea level data subject to the following conditions: i) When any data supplied by the National Tidal Facility is used in any publication or report, the origin of such data shall be acknowledged in that publication or report in the following approved form:-- "Tidal {predictions) for {port} {are} supplied {constants} {station} {is} {material} {...} by the National Tidal Facility, The Flinders University of South Australia, Copyright reserved." ii) All material is supplied in good faith and is believed to be correct. It is supplied on the condition that no warranty is given in relation thereto, that no responsibility or liability for errors or omissions is, or will be, accepted and that the recipient will hold the Flinders Univer- sity of South Australia and the National Tidal Facility free from all such responsibility or liability and from all loss or damage incurred as a consequence of any error or omission. iii) The acceptance of material and computations from the National Tidal Facility of the Flinders University of South Australia will be deemed to include acceptance of the conditions of supply. CI MISSING REPLACED GAPS QUESTIONABLE YEAR (%) DATA OR BAD DATA FLUCTUATIONS ---- --- -------------------- --------------- -------------------- 1988 100 none none see comment above 1989 86 166-219 none see comment above 1990 99 92-93,239-241 (01)230-(21)230 see comment above (12)236-(09)237 (09)251-(20)251 (23)268-(08)269 (21)299-(20)300 1991 96 20-28,345-352 (08)009-(06)010 see comment above 1992 85 45-98 none see comment above 1993 90 106-143,206-208 none see comment above 1994 99 312-314 none see comment above 1995 87 60-107 (03)226-(02)227 see comment above 1996 100 none none see comment above 1997 71 104-210 none see comment above 1998 52 23-120 none see comment above 1999 95 1-15,78-83,291-292 (20)331-(17)332 see comment above