QUALITY ASSESSMENT OF SEA LEVEL DATA by the UH SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER JOINT ARCHIVE FOR SEA LEVEL Station : Lamu-A Latitude: 02 16.3S Country : Kenya Longitude: 040 54.2E JASL # : 149A Time Meridian: 045E (GMT + 3 hr) GLOSS # : none TOGA #: none NODC #: 30042001 Contributor : Kenya Marine and Fisheries Institute P. O. Box 81651 Mombasa, Kenya Originator : same Original Data: analog Instrmnt Type: ValePort BTH 700, float gauge (1989); Unknown pressure transducer (1990-1991) 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 : 01 Jan 1989 - 30 Nov 1991 Gaps > 1 mon : 01 Jan 1990 - 01 Jun 1990;29 Nov 1990 - 06 Mar 1991 Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 Units : millimeters Missing Data Flag : 9999 Existing : No Operational : No Sat. Trans. : No Distribution : 1989-1989 Refernce Levl: The sea level heights are referred to the zero point assigned to the tide staff. Bench mark information is available upon request. The 1990-1991 have not been calibrated to the same reference level as the 1989 data. Comment : The daily and monthly means do not reveal any reference level shifts or trends during 1989, but the 1990-1991 data have questionable level shifts. Also, the 1990-1991 plots of the hourly data showed no data available for roughly 4 hours around the lowest low water tides. This could be do to silting within the well, or misalignment of the analog paper. For most of 1989, and all of 1990-1991, timing errors were evident in the hourly data. CI MISSING REPLACED GAPS QUESTIONABLE YEAR (%) DATA OR BAD DATA FLUCTUATIONS ---- --- -------------------- --------------- -------------------- 1989 90 30-31,365 (22)059-(06)060 4,7-12,20-27,36-42, (02)149-(13)149 49-56,94-102,109- (14)191-(21)191 116,124-125,197,201- (22)212-(05)213 202,213-215,226-234, (10)255-(18)255 240-244,291-302, (08)258-(21)258 305-311,322-323 (03)259-(09)259 (13)266-(20)266 (00)273-(19)273 (14)307-(07)308 1990 50 1-152,213-214, (09)266-(06)267 see comment above 333-365 (16)294-(07)295 1991 58 1-65,93-98,109-121, (13)085-(00)086 see comment above 125-127,159-161,180- (13)136-(00)137 181,184-213,244-245, (23)161-(10)162 248-249,253-255,302- (00)232-(11)232 306 (01)239-(12)239 (13)264-(00)265 (01)290-(12)290 (21)315-(12)316