QUALITY ASSESSMENT OF SEA LEVEL DATA by the UH SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER JOINT ARCHIVE FOR SEA LEVEL updated: 05 Apr 2004 Station : Settlement Point-A Latitude: 26 42.6N Country : Bahamas Longitude: 078 59.8W JASL # : 257A Time Meridian: 075W (GMT - 5 hr) GLOSS # : 211 Originator #:9710441 NODC #: 72076801 Contributor : UH Sea Level Center University of Hawaii at Manoa Honolulu, Hawaii 96822 USA For the pre-1999 data: National Ocean Service (NOS) National Ocean. and Atmos. Administration (NOAA) N/OES22 SSMC4, STATION 7109 1305 East West Highway Silver Spring, MD. 20910-3233 Originator : same Original Data: digital Instrmnt Type: 1) analog-to-digital (ADR) recorder (1/1/1985- 12/31/1992) float and well system; 2) Aquatrak acoustic gauge, NOAA Next Generation Water Level Measuring System (NGWLMS) (1993-10/2001) 3) Waterlog Pressure sensor (11/2001-06/2002) Digitzd Intvl: six-minute (NGWLMS sampling is three-minute ave.) Present Data : Hourly, daily, and monthly values obtained by: Hourly : spot sampling 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 : 19 Oct 1985 - 06 Jun 2002 Gaps > 1 mon : 25 Dec 1988 - 02 Feb 1989;09 Feb 1989 - 11 Apr 1989 01 May 1998 - 22 Jun 1998;28 Jun 1998 - 17 Nov 1998 16 Nov 1999 - 31 Dec 1999;15 Dec 2001 - 18 Apr 2002 Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 Units : millimeters Missing Data Flag : 9999 Existing : Yes Operational : No Sat. Trans. : Yes Distribution : 1985-2002 Refernce Levl: All heights have been referred to the station tide staff zero which is linked to fixed bench marks. 30 feet (9144 mm) was subtracted from originator's data in order to fit the JASL format. While standard mechanical or ADR instrument was the primary gauge, leveling calibration factors were applied monthly based on tide staff comparisons. Comment : The daily and monthly values agree fairly well with Key West and Miami and do not show any obvious shifts or trends. An anomalously low seasonal signal occurs in Sept - Dec 1987. The data from the Waterlog pressure sensor is of less quality, use with discretion. In June 2002, this site was discontinued. A new station was installed about 3 miles away. At present, the reference level link from the old to the new has not been established; thus, the series are kept separate. CI MISSING REPLACED GAPS QUESTIONABLE YEAR (%) DATA OR BAD DATA FLUCTUATIONS ---- --- -------------------- --------------- -------------------- 1985 20 none none none 1986 100 none none none 1987 100 none (19)047-(03)048 none 1988 98 360-365 none 81-82,161-162 1989 62 1-33,40-101,145-148, none 111-121,232-246 246-279 1990 100 none none none 1991 100 none none none 1992 100 none none none 1993 100 none none none 1994 100 none none none 1995 92 70-98 (15)100-(14)102 none (08)113-(06)115 (15)255-(15)256 1996 100 none none none 1997 100 none none none 1998 47 121-173,179-321 none none 1999 95 5-14,320-329 none none 2000 100 none none none 2001 96 349-365 none none 2002 12 1-108 none none