QUALITY ASSESSMENT OF SEA LEVEL DATA by the UH SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER JOINT ARCHIVE FOR SEA LEVEL Station : Quepos Latitude: 09 24.0N Country : Costa Rica Longitude: 084 10.0W JASL # : 087A Time Meridian: 090W (GMT - 6 hr) GLOSS # : 167 TOGA #: P078 NODC #: 70089401 Contributor : SERMAR, Instituto Meteorologico Nacional Apartado 7-3350 San Jose, COSTA RICA and for the 1987-1992 ADR data, collaboration with Atlantic Oceanographic and Meteor. Lab. (AOML) 4301 Rickenbacker Causeway Miami, Florida 33149 and UH Sea Level Center 1000 Pope Rd. MSB 317 Honolulu, Hawaii 9682 The 1961-1965 data were obtained from Scripps Institute of Oceanography University of California at San Diego La Jolla, California Originator : same Original Data: analog (standard); digital (ADR) Instrmnt Type: Standard mechanical float type tide gauge (1961-65) Leupold Stevens analog-to-digital recorder (ADR) (11/1986-present) (backup); Fischer and Porter ADR (4/1992-) Digitzd Intvl: one hour (standard); 6 minute (ADR) Present Data : Hourly, daily, and monthly values obtained by: Hourly : Spot sample on the hour (analog and LS ADR); 3-pt Hanning centered on the hour (FP ADR) 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 Jan 1961 - 31 Dec 1994 Gaps > 1 mon : 01 Jan 1966 - 31 Dec 1970;1 Mar - 4 Apr 1973; 30 Aug 1991 - 02 Oct 1991; 01 Jan - 01 Feb 1992 Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 Units : millimeters Missing Data Flag : 9999 Existing : Yes Operational : Yes Sat. Trans. : No Distribution : 1961-1994 Refernce Levl: The data have been linked to tide staff zero by the contributors. However, further analysis of the data has led to adjustments of the reference level in separate segments. All suspected shifts showed step function jumps in the plots of hourly residuals and of differences of daily values with the nearest stations. These ad- justments contain uncertainty to a few centimeters. period value added ( (hour)day/month/year ) to original(mm) --------------------------- --------------- (00)02/05/72 - (16)01/06/72 80 (16)01/06/77 - (16)01/07/77 100 (16)01/09/79 - (16)01/10/79 100 (16)01/11/83 - (16)01/12/83 -130 (12)01/06/82 - (16)26/04/84 100 (17)01/02/86 - (15)01/03/86 -180 (16)01/03/86 - (12)01/04/86 40 (13)01/04/86 - (22)01/05/86 260 (13)29/03/86 - (01)03/08/86 -100 Comment : The data from the standard analog gauge showed many distinct shifts at the beginning of some months throughout the record. All obvious shifts have been adjusted as noted above; however, the long-term reference level stability is uncertain. The analog data from 1 Apr 1988 - 30 Sep 1990 were replaced with ADR data which also have been linked to tide staff zero. The ADR data were used to fill small gaps in the analog record (see # below) and analog data were used to fill gaps in the ADR (*). Data from 1 - 17 Jun 1991 appear 15 cm high. Severe timing errors associated with gauge problems occurred from Sep - Nov 1985. The timing has an uncertainty of about +/- 7 minutes. The hourly residuals of the ADR data show considerable noise; thus the hourly ADR data are of less quality than the daily or monthly ADR data. As of 4/92, the FP ADR is the primary gauge. CI MISSING REPLACED GAPS QUESTIONABLE YEAR (%) DATA OR BAD DATA FLUCTUATIONS ---- --- -------------------- --------------- -------------------- 1961 99 1 none none 1962 100 none none none 1963 100 none (15)055-(12)056 none 1964 99 30-33 none none 1965 100 none (14)288-(00)289 none 1966 0 1-365 none none 1967 0 1-365 none none 1968 0 1-366 none none 1969 0 1-365 none none 1970 0 1-365 none none 1971 99 290-292 (10)087-(03)088 247-248,335-336, (20)116-(05)117 359-360 (23)251-(05)252 (12)365-(23)365 1972 98 92-96 (00)001-(11)001 61-67,73-98,103-122, (12)245-(03)246 147-151,189-190,193- (12)275-(20)275 194,245,259-260 1973 88 60-94,98-106 (12)001-(20)001 47,96-98,157-158, 196-198,226-229,257- 258,262-263,270-271 1974 100 none none 27-28,62-63,166,213- 283,337 1975 91 91-121 none 1-2,40,42-43,61-62, 73,81-83,91,237,252 1976 99 300-301 (15)351-(21)351 212 (17)357-(16)358 1977 98 22-24,31-32, none 45,62,159,216-217 146-148 1978 99 87-88,152-154 (22)046-(21)047 86-87,148-151,305 1979 100 none none none 1980 100 none none 3,364 1981 100 none none 176,206-212 1982 100 none none none 1983 100 none none 134-135,170 1984 100 none none 186,299,302 1985 90 139-141,188-196, none 148,221-222,242-271, 200-204,271-274, 274-280,295-308, 281-295,348-350 313-322 1986 98 215-217,305-309 none 12-13,264-265,312, 336,341,347-350, 357-358,362-363,365 1987 99 139-140,221-222 (00)108-(11)108 4-5,14-16,26-27, #(15)081-(17)083 29-30,41,47,49-51, #(00)272-(23)275 53-54,57-58,61,63- #(14)347-(14)349 64,67-68,72-73,77- 78,87-88,94-96,101- 103,155-156 1988 100 none (05)147-(15)147 152-160,165-167,180- 183,203-204,215,228- 230,237,254-256 1989 100 none none 244-249,264-265,283- 284,286,293-294 1990 100 none (00)227-(15)227 93,243-244,270-271 (19)281-(12)282 (02)283-(13)283 (17)287-(04)288 (07)305-(18)305 (01)331-(11)331 (16)334-(12)335 *(17)196-(13)200 1991 90 89-91,168-171, (06)001-(15)001 17-18,25,27-28,75, 243-275 (06)020-(05)021 153,164-167,209-214, (21)056-(12)057 217-230,233-242 (19)081-(12)082 (00)138-(22)138 (14)180-(01)181 #(11)015-(13)016 #(23)058-(12)060 1992 90 1-33,92-93,183-184 (06)061-(13)061 none (03)085-(12)085 (01)336-(18)336 1993 100 none none none 1994 99 333-334 (18)290-(16)291 none (12)303-(01)304 (08)360-(19)360