QUALITY ASSESSMENT OF SEA LEVEL DATA by the UH SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER JOINT ARCHIVE FOR SEA LEVEL updated: 22 Sep 2020 Station : Charlotte Amalie Latitude: 18 20.1N Country : USA Longitude: 064 55.2W JASL # : 255A Time Meridian: 060W (GMT - 4 hr) GLOSS # : none Originator #:9751639 NODC #: 71068401 Contributor : 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) 1978-5/93, Analog-to-Digital Recorder (ADR) 2) 6/1993-, Aquatrak acoustic gauge, NOAA Next Generation Water Level Measuring System (NGWLMS) Digitzd Intvl: 6 minute (each sampling is three-minute average) Present Data : Hourly, daily, and monthly values obtained by: Hourly : Discrete 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 : 01 Oct 1978 - 31 Dec 2019 Gaps > 1 mon : 05 Apr 1979 - 16 Apr 1980;12 Oct 1980 - 13 Nov 1980 10 Feb 1981 - 04 May 1981;03 Jun 1981 - 25 Nov 1981 18 Dec 1981 - 05 Jan 1982;27 Dec 1982 - 19 Feb 1983 06 Sep 1992 - 24 Feb 1993;01 Aug 2002 - 31 Aug 2002 30 Nov 2005 - 28 Feb 2006;04 Apr 2006 - 22 Jun 2006 14 Jul 2007 - 15 Aug 2007;06 Sep 2017 - 21 Jun 2018 Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 Units : millimeters Missing Data Flag : 9999 Existing : Yes Operational : Yes Sat. Trans. : No Distribution : 1978-2019 Refernce Levl: All heights have been referred to the station tide staff zero which is linked to fixed bench marks. 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 do not show any level problems and agree reasonably well with Limetree Bay,St. Croix and San Juan, Puerto Rico, except for a minor difference of a few cm beginning in Nov 1995 through 1996. This feature is under investigation by the originators. The monthly values reveal a consistent annual signal. The sharp rise on 18 Sep 1989 is due to Hurricane Hugo. A hurricane is associated with the anomaly on 16 Sep 1995. Several gaps have been filled by NOS using redundant sensors and interpolation as noted below. CI MISSING REPLACED GAPS QUESTIONABLE YEAR (%) DATA OR BAD DATA FLUCTUATIONS ---- --- -------------------- --------------- -------------------- 1978 25 none (06)313-(11)313 none (20)345-(11)346 1979 26 95-365 none none 1980 51 1-107,208-220,224- (15)126-(11)127 239-286 238,286-318 (19)319-(16)320 1981 26 41-124,154-329 none none 352-365 1982 98 1-5,361-365 (07)086-(13)086 none 1983 85 1-50 none none 1984 100 none (01)004-(22)005 none 1985 94 307-329 (05)116-(09)122 none (04)329-(16)331 1986 98 30-37 none none 1987 100 none none none 1988 100 none (17)095-(20)097 none 1989 100 none none none 1990 100 none none none 1991 100 none none none 1992 68 250-366 none none 1993 85 1-55 (04)151-(23)151 none 1994 100 none none none 1995 100 none (17)034-(15)035 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 2002 92 213-243 (17)094-(00)095 none 2003 100 none none none 2004 100 none none none 2005 92 335-365 none none 2006 62 1-59,94-173 none none 2007 80 93-108,159-165,173- (16)171-(13)172 32-48 177,181-184,295-227, (03)254-(02)255 237-247,249-252 2008 100 none none none 2009 94 272-295 none none 2010 100 none none none 2011 100 none none none 2012 100 none none none 2013 100 none none none 2014 100 none none none 2015 100 none none none 2016 100 none none none 2017 68 249-365 none none 2018 53 1-172 none none 2019 100 none none none