QUALITY ASSESSMENT OF SEA LEVEL DATA by the UH SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER JOINT ARCHIVE FOR SEA LEVEL updated: 22 Aug 2019 Station : Tanjong Pagar Latitude: 01 15.7N Country : Singapore Longitude: 103 51.2E JASL # : 699A Time Meridian: 120E (GMT + 8 hr) GLOSS # : 044 Originator #: NODC #: 10101305 Contributor : Maritime and Port of Singapore Authority Hydrographic Department 7B Keppel Road #13-07 Tanjong Pagar Complex Singapore 089055 Originator : same Original Data: analog; digital (acoustic) Instrmnt Type: A.OTT Float Type; Acoustic gauge (12/1996+) Digitzd Intvl: 1 hour; 6 min (acoustic) Present Data : Hourly, daily, and monthly values obtained by: Hourly : digitized from chart paper (analog); spot sampled on hour (6 min) 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 1984 - 31 Dec 2018 Gaps > 1 mon : 30 Apr 1995 - 30 Jun 1995;31 Aug 1995 - 11 Nov 1995 05 May 2001 - 02 Jul 2001;31 Dec 2001 - 06 Feb 2002 Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 Units : millimeters Missing Data Flag : 9999 Existing : Yes Operational : Yes Sat. Trans. : No Distribution : 1988-2018 Refernce Levl: The sea level heights are referred to the chart datum which is also the zero level of the tide gauge. Bench mark information is available upon request from the contributors. Comment : The residual series are very noisy, which is due to shallow water tides that are not resolved by the harmonic analysis or due to timing drifts of less than 15 minutes. Since the newer acoustic gauge of higher timing resolution, a similar signature remains. Thus, it is clear the timing is relatively good and the fluctuations in the residuals are a reflection of unresolved tidal constituents. The differences in daily values with Keppel Harbor and Johor Bahru suggest subtle level shifts on 28 Aug 1984, 29 Oct 1984, 9 Nov 1984, 9 May 1985, 01 May 1986. The differences also show unusually low values for most of 1987. The data of the acoustic gauge are of higher quality. The 1993-2018 daily means agree well altimeter CMEMS data suggesting a stable reference level. CI MISSING REPLACED GAPS QUESTIONABLE YEAR (%) DATA OR BAD DATA FLUCTUATIONS ---- --- -------------------- --------------- -------------------- 1984 100 none none none 1985 100 none none none 1986 100 none none none 1987 99 197-202 none none 1988 99 92-95 none none 1989 95 250-257,309-319 none none 1990 97 314-316,323-326,331- none none 334,358-362 1991 93 33-39,70-72,83-89, none none 91-100,335-338 1992 88 7-16,189-219,225-230 none none 1993 100 none none none 1994 90 10-32,161-167,170- none none 173,352-358 1995 50 46-55,58-67,97-110, none none 120-181,205-206,210- 215,243-314,332-338, 345-353 1996 95 80-98 none none 1997 100 none (03)091-(16)091 none (17)191-(01)192 (17)359-(16)360 1998 100 none none none 1999 95 119-123,140-153, (21)282-(04)283 none 349-351 2000 99 353-355 none none 2001 82 29-36,125-183, none none 361-362,365 2002 90 1-37 (17)144-(00)145 none (17)145-(01)146 (11)146-(02)147 (13)147-(01)148 2003 100 none none none 2004 97 12-14,70-72,172-174, none none 213-215,220-224 2005 97 109-116,158-160,274- (15)255-(08)256 none 276,326-327 (11)261-(18)261 (09)262-(00)263 (08)263-(01)264 2006 99 291-292 (13)363-(00)364 none 2007 99 12-15 none none 2008 100 none none none 2009 100 none (16)158-(01)159 none 2010 99 69-74 (20)257-(06)258 none (09)258-(02)259 (10)259-(07)260 2011 100 none none none 2012 100 none none none 2013 100 none (16)021-(01)022 none 2014 100 none (08)027-(05)028 none 2015 98 204-212 none none 2016 100 none none none 2017 100 none none none 2018 99 365 (10)346-(00)347 none