QUALITY ASSESSMENT OF SEA LEVEL DATA by the UH SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER JOINT ARCHIVE FOR SEA LEVEL Station : Port Victoria-A Latitude: 04 37.3S Country : Seychelles Longitude: 055 27.5E JASL # : 111A Time Meridian: 060E (GMT + 4 hr) GLOSS # : none TOGA #: I053 NODC #: 30054501 Contributor : Institute of Oceanographic Sciences (IOS) Bidston Observatory, Birkenhead Merseyside L43 7RA Originator : same Original Data: analog Instrmnt Type: Munroe, No 1861/593/280 Digitzd Intvl: one hour spot reading Present Data : Hourly, daily, and monthly values obtained by: Hourly : The original digitizing interval was hourly 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 : 17 Jun 1975 - 15 Oct 1984 Gaps > 1 mon : 03 Aug - 13 Dec 1976; 31 Dec 1976 - 15 Dec 1977 Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 Units : millimeters Missing Data Flag : 9999 Existing : No Operational : No Sat. Trans. : No Distribution : 1977-1982 Refernce Levl: The sea level heights are referred to the zero point assigned to the tide gauge. Comment : The reference level appears stable during Dec 1977 - Aug 1983. Relative to this period, 1975- 1976 appears low by about 10 cm and Sep 1983 - Oct 1984 appears high by about 10 cm. CI MISSING REPLACED GAPS QUESTIONABLE YEAR (%) DATA OR BAD DATA FLUCTUATIONS ---- --- -------------------- --------------- -------------------- 1975 54 none none none 1976 63 196-199,216-348, none 186,209-213 366 1977 04 1-349 none none 1978 100 none none none 1979 100 none none none 1980 98 140-143,160-163, none 122-123,240,270,282 214-217,336-338 1981 96 43-50,74-75, (15)167-(09)168 33-34,155-156 96-98,137-138, 187-189,201-203, 239-240 1982 99 16-19 none 101,127-130,230-234 1983 94 150-154,236-250, none 131-133,329-331 350-353 1984 79 none none 10-12,14-17