QUALITY ASSESSMENT OF SEA LEVEL DATA by the UH SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER JOINT ARCHIVE FOR SEA LEVEL Station : Colombo-B Latitude: 06 56.9N Country : Sri Lanka Longitude: 079 51.2E JASL # : 115B Time Meridian: 82.5E (GMT + 5.5) GLOSS # : 033 TOGA #: I035 NODC #: 10076901 Contributor : UH Sea Level Center 1000 Pope Rd. MSB 317 Honolulu, Hawaii 96822 Originator : UH Sea Level Center in collaboration with National Aquatic Resources Agency Crow Island, Mattakkuliya Colombo-15 SRI LANKA Original Data: digital Instrmnt Type: Fischer and Porter Analog-to-Digital Recorder Digitzd Intvl: 15 minutes Present Data : Hourly, daily, and monthly values obtained by: Hourly : A three-point Hanning filter centered on the hour 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 : 14 Jul 1989 - 28 Aug 1992 Gaps > 1 mon : 01 Jun - 30 Jun 1992 Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 Units : millimeters Missing Data Flag : 9999 Existing : Yes Operational : Yes Sat. Trans. : No Distribution : 1989-1992 Refernce Levl: Heights are referred to the station tide staff zero, which is linked to land-based benchmarks. This reference zero is unique to this station and is not an official datum (chart, national, etc.) and is not relative to local tidal parameters, such as mean lower low water. See the Originators for benchmark descriptions, maps, and the geodetic levelling history. Comment : The daily and monthly values do not reveal any obvious reference level shifts or trends. CI MISSING REPLACED GAPS QUESTIONABLE YEAR (%) DATA OR BAD DATA FLUCTUATIONS ---- --- -------------------- --------------- -------------------- 1989 47 none none none 1990 99 196-197 none none 1991 97 140-141,235-239,305- (11)161-(10)162 none 308,340-345 1992 56 26-28,47-50,153-182 (18)214-(17)215 none