QUALITY ASSESSMENT OF SEA LEVEL DATA by the UH SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER JOINT ARCHIVE FOR SEA LEVEL updated: 25 May 2011 Station : Saint Paul Latitude: 38 42.7S Country : France Longitude: 077 32.3E JASL # : 179A Time Meridian: 075E (GMT + 5 hr) GLOSS # : 024 TOGA #: none NODC #: 33078701 Contributor : Service d'Observation ROSAME, LEGOS/OMP 14 Ave. Edouard Belin 31400 Toulouse FRANCE Originator : same Original Data: digital Instrmnt Type: Aanderaa WLR7 tide recorder. The gauge is installed in the crater of a partially submerged volcano, communicating with the open ocean through a narrow (100m) and shallow (2m at low tide) pass. This bottom pressure sensor is at the base of a stilling well which is used to filter waves. The recorder is triggered by a central unit where the barometric pressure is measured at the same time. Digitzd Intvl: hourly Present Data : Hourly, daily, and monthly values obtained by: Hourly : Four minute integration time centered on the hour is used for the bottom pressure measurement. Data are transmitted via ARGOSS to Toulouse. The data are then processed to decrypt the messages and compute sea level based on i) relative bottom pressure, ii) water temperature, and iii) barometric pressure. From this set of data in combination with salinity, which is periodically measured but is assumed to be constant over extended periods, one computes water density based on the UNESCO formula for the sea-water equation; thus, the sea level is deduced. THIS DATA SET IS THE DIRECT MEASURE OF SEA LEVEL, assuming the water density has been properly estimated. The data set DOES include variations caused by atmospheric pressure changes on sea level; i.e., it DOES include the inverse barometer effects in the signal. 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 : 25 Oct 1994 - 24 Dec 2006 Gaps > 1 mon : 06 Apr 1999 - 23 Nov 1999;03 Dec 2002 - 16 Jan 2003 Time Refernce: GMT (00-23 hours) Space-filler Flag :-9999 Units : millimeters Missing Data Flag : 9999 Existing : Yes Operational : Yes Sat. Trans. : Yes Distribution : 1994-2006 Refernce Levl: Presently no link is established between the tide gauge and fixed bench marks. Please refer to the originator for the up-to-date status. Comment : Pressure transducers typically have long-term tendencies to drift. However, the originators have calibrated the instrument before deployment and due to the shallow resting level of the pressure sensor, the potential drift would be very small. Post-retrieval calibrations have not been performed. Please refer to the originators for the up-to-date status. For this data set, no explicit correction has been applied in this regards. The plot of the hourly data minus the predicted tides reveals data with mostly excellent timing characteristics. Some extreme peaks seen in the daily plots are associated with weather events. CI MISSING REPLACED GAPS QUESTIONABLE YEAR (%) DATA OR BAD DATA FLUCTUATIONS ---- --- -------------------- --------------- -------------------- 1994 18 none none none 1995 92 1-31 none none 1996 100 none (01)306-(17)306 none (01)319-(17)319 1997 100 none none none 1998 100 none (00)042-(09)042 none (00)099-(21)099 (13)311-(02)312 (12)345-(02)346 1999 33 29-34,86-90,91-92, (12)018-(02)019 none 96-327 (15)092-(08)093 (12)095-(04)096 2000 100 none (14)325-(04)326 none (01)328-(15)328 2001 97 171-174,181-182,185- (02)166-(18)166 none 192,209-210 (02)167-(13)167 (20)168-(07)169 (02)183-(13)183 (15)183-(13)184 (20)189-(07)190 (15)205-(06)206 (20)208-(08)209 2002 96 324-326,334-365 (00)166-(13)166 none (11)169-(01)170 (18)236-(07)237 (15)238-(10)239 (14)239-(03)240 (15)254-(07)255 (14)256-(03)257 (21)318-(10)319 (19)332-(08)333 2003 96 1-16 (20)362-(09)363 none 2004 100 none none none 2005 100 none (09)019-(21)019 none 2006 87 57-96 none none