QUALITY ASSESSMENT OF SEA LEVEL DATA by the UH SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER JOINT ARCHIVE FOR SEA LEVEL Station : Hiva Oa-A Latitude: 09 48.6S Country : French Polynesia Longitude: 139 01.6W JASL # : 017A Time Meridian: 142.5W (GMT - 9.5) GLOSS # : none TOGA #: none NODC #: 50139901 Contributor : UH Sea Level Center 1000 Pope Rd. MSB 317 Honolulu, Hawaii 96822 Originator : Dept. of Oceanography University of Hawaii 1000 Pope Rd. MSB 317 Honolulu, Hawaii 96822 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 : Nine-point triangular filter centered on the hour with respective periods of the 95, 50, and 5% amplitude point of the filter response at 623.6, 177.0, and 103.7 minutes 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 : 28 Oct 1977 - 02 Oct 1980 Gaps > 1 mon : 19 Mar - 23 May 1979; 30 June - 1 Aug 1979; 9 Nov 1979 - 8 Jan 1980; 31 Jul - 2 Sep 1980 Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 Units : millimeters Missing Data Flag : 9999 Existing : No Operational : No Sat. Trans. : No Distribution : 1977-1980 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 means reveal no apparent changes in the reference level. The timing is no better than plus or minus 7.5 minutes. The station has been discontinued. This series is separate from 017B since they are not linked to the same datum. CI MISSING REPLACED GAPS QUESTIONABLE YEAR (%) DATA OR BAD DATA FLUCTUATIONS ---- --- -------------------- --------------- -------------------- 1977 16 335-339 none 309-326,330,334, 343-349,358 1978 98 262-267 none 8,150-151,333 1979 52 14-17,78-143, none 49-50,54-55,58-78, 181-244 143-148,276-285 1980 56 1-8,134-158, none none 175-177,208-210, 213-246