QUALITY ASSESSMENT OF SEA LEVEL DATA by the UH SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER JOINT ARCHIVE FOR SEA LEVEL updated: 24 Apr 2002 Station : Funafuti Latitude: 08 31.5S Country : Tuvalu Longitude: 179 11.7E JASL # : 025A Time Meridian: 180E (GMT + 12 hr) GLOSS # : 121 TOGA #: P046 NODC #: 30178901 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 and for filling gaps in 1993-1998 data and primary source for 2000+ : The National Tidal Facility (NTF) Flinders University of South Australia GPO Box 2100 Adelaide, 5001, South Australia AUSTRALIA Note: The NTF gauge is about 1.5 miles from UH gauge at 08 30.14S and 179 11.70E Original Data: digital Instrmnt Type: 1. (Oct 1977 - Aug 1986 )Fischer and Porter Analog-to-Digital Recorder (ADR) 2. (Aug 1986-May 1990) Leupold and Stevens Analog-to-Digital Recorder (ADR); 3. (Aug 1986-present) Handar Encoder 436A (ENC) 4. (Jul 1988-present) Handar Encoder 436B (ENB) with datalogger (ENO) 5. NTF: Aquatrak acoustic gauge (SEAFRAME) Primary gauge: ADR:1974-4/90, ENC 5/1990-1994 ENB: 1995-1999, NTF: 2000- Digitzd Intvl: 15 min (ADR,ENB,ENO); 3 or 4 (ENC); 6 (NTF) Present Data : Hourly, daily, and monthly values obtained by: Hourly : (pre-1987) 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;(1987+) 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 : 17 Oct 1977 - 31 Dec 2001 Gaps > 1 mon : 10 Jul - 14 Aug 1979; 10 Dec 1980 - 11 Feb 1981 Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 Units : millimeters Missing Data Flag : 9999 Existing : Yes Operational : Yes Sat. Trans. : Yes Distribution : 1977-2001 Refernce Levl: All heights have been referred to the station tide staff zero which is linked to fixed bench marks. The NTF series was tied to the historic series by subtracting 772 mm. Comment : The daily and monthly means reveal no apparent changes in the reference level and agree with Honiara and Penrhyn. Timing accuracy prior to 1984 is no better than plus or minus 8 minutes. Gaps filled with NTF data noted with * if gap length > 6 hr. Many shorter gaps filled with NTF data are documented and available from the UHSLC. CI MISSING REPLACED GAPS QUESTIONABLE YEAR (%) DATA OR BAD DATA FLUCTUATIONS ---- --- -------------------- --------------- -------------------- 1977 21 none none 314-315 1978 97 162-164,213-216, (09)217-(22)217 95-99,115,145-146, 220-222 (03)218-(23)218 201-204,228-233,246- 247,252-263,299-308 1979 76 39-55,69-71, none 111-116,233-234,250, 88-103,191-226, 305-308 236-239,272-276, 287-290,343-345 1980 86 63-80,82-87, none 238-243,268-270, 135-136,222-223, 282-283 246-247,345-366 1981 83 1-42,93-95, none 167,177-178,183-184, 115-123,149-153, 210-212,343-347 224-227 1982 99 275-276,296-297 none 141-146,256-260,318 1983 93 12-17,77-86, none 160-164,190 125-127,232-237 1984 100 none none none 1985 100 none none none 1986 100 none none none 1987 100 none none none 1988 100 none none none 1989 100 none none none 1990 100 none none none 1991 100 none none none 1992 100 none none none 1993 100 none *(00)182-(23)186 none 1994 100 none none none 1995 100 none none none 1996 100 none none none 1997 100 none none none 1998 100 none none none 1999 100 none none none 2000 100 none none none 2001 100 none none none