QUALITY ASSESSMENT OF SEA LEVEL DATA by the UH SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER JOINT ARCHIVE FOR SEA LEVEL updated: 06 Nov 2019 Station : La Libertad Latitude: 02 12.0S Country : Ecuador Longitude: 080 55.0W JASL # : 091A Time Meridian: 075W (GMT - 5 hr) GLOSS # : 172 Originator #:071 NODC #: 50082001 Contributor : Instituto Oceanografico de la Armada Casilla Postal 5940 Telex 3316 INOCAR-ED Guayaquil, Ecuador and for 1986-1988 ADR data Atlantic Oceanographic and Meteorological Lab. 4301 Rickenbacker Causeway The historic 1949-1969 data were contributed by D.Luther (Univ. of Hawaii). Starting 08/2011, in collaboration with UH Sea Level Center 1000 Pope Rd. MSB 317 Honolulu, Hawaii 96822 Originator : Instituto Oceanografico de la Armada Casilla Postal 5940 Telex 3316 INOCAR-ED Guayaquil, Ecuador Original Data: analog (mechanical); digital (others) Instrmnt Type: 1. standard mechanical tide gauge (1949-); 2.Leupold Stevens analog-to-digital recorder(ADR) (5/1985-); 3.Handar Encoder (ENC) model 436A (5/1985-) 4. Bubbler pressure gauge (BUB) 5. 08/2011- Pressure transducer (PRS) 6. 08/2011- radar (RAD) Vega Vegapuls 62 Primary channel: 1949-18 Aug 2011: mechanical, ADR, or ENC 18 Aug 2011- 05/2012 : ENC 06/2012 - : RAD Digitzd Intvl: one hour (mechanical); 15 min (ADR); 4 min (ENC); 2 min (BUB); 3 min (RAD); 2 min (PRS) Present Data : Hourly, daily, and monthly values obtained by: Hourly : The original digitizing interval was hourly (analog); a Hanning three-point filter centered on the hour (others) 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 Sep 1949 - 31 Dec 2018 Gaps > 1 mon : 29 Jun 1956 - 13 Aug 1956;11 Nov 1956 - 01 Jan 1957 08 Jun 1957 - 23 Jul 1957;19 Feb 1962 - 03 Jun 1962 01 Oct 1971 - 01 Sep 1971;01 Oct 1977 - 03 Dec 1977 01 Nov 2003 - 01 Jan 2004;14 May 2004 - 23 Jul 2004 02 Nov 2005 - 01 Jan 2006;01 Apr 2016 - 01 May 2016 Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 Units : millimeters Missing Data Flag : 9999 Existing : Yes Operational : Yes Sat. Trans. : Yes Distribution : 1949-2018 Refernce Levl: The level stability is uncertain throughout the series although this data set is the UHSLC "best guess" based on various analysis techniques. The data have been linked to tide staff zero by the contributors. However, further analysis of the data has lead to adjustments of the reference level in separate segments. The following adjustments were based upon comparisons with Callao, Talara, and PSMSL historic data. For each adjustment, step-like jumps could be identified in the hourly residuals. period value added ( (hour)day/month/year ) to original(mm) --------------------------- --------------- (16)01/04/50 - (12)21/06/50 70 (16)23/10/51 - (03)01/11/51 -130 (08)01/07/52 - (11)12/07/52 100 (21)30/10/53 - (05)01/12/53 -70 (09)26/12/53 - (16)26/12/54 -60 (14)03/01/55 - (21)09/01/55 70 (20)30/09/56 - (20)12/10/56 -70 (00)01/01/57 - (06)10/01/57 170 (07)10/01/57 - (15)23/01/57 220 (22)22/06/57 - (22)18/07/57 -130 (22)01/10/62 - (19)09/10/62 -120 (16)24/06/64 - (13)26/06/64 150 (15)01/01/65 - (23)01/01/66 100 *(07)25/02/69 - (14)01/03/69 130 (19)27/12/68 - (14)01/09/69 -70 (15)01/09/69 - (14)07/09/69 50 *Adjustment applied prior to adjustment noted on the following line. The 1/1970-2/1971 data were tied to the historic series 1949-1969 based on 9-12/1969 overlap by adding 416 mm. Then, the series from 1949-2/1971 was linked to the remaining series based on PSMSL data overlap by adding -595 mm. The following adjustment was based upon reanalysis of the tide staff observation sheets by Mr. Henry Pittock of Oregon State University: period value added ( (hour)day/month/year ) to original(mm) --------------------------- --------------- (13)16/08/83 - (14)01/09/83 10 The following adjustments were determined by comparisons with the ADR and ENC data, and with analog data from Callao, Peru. period value added ( (hour)day/month/year ) to original(mm) --------------------------- --------------- (19)01/01/87 - (00)15/01/87 -80 (00)01/08/87 - (12)01/09/87 -40 (20)05/10/87 - (13)15/10/87 -40 (10)02/11/87 - (10)01/12/87 -40 (05)01/01/88 - (19)02/03/88 -30 (20)02/03/88 - (05)03/04/88 -70 (06)03/04/88 - (07)01/05/88 -30 (08)01/05/88 - (21)14/05/88 -10 (22)14/05/88 - (11)15/07/88 -60 (12)15/07/88 - (23)30/09/88 -20 (00)01/08/94 - (23)30/09/94 235 (14)29/07/04 - (17)05/08/04 420 The above adjustments are uncertain to a few cm. In August 2011, all data prior to 2007 were adjusted by +360 mm to relate to the present reference level as provided by the originators. Aug 2015 JASL update: level corrections based on daily data differences with Baltra, Santa Cruz, and Callao with AVISO validation: period value added ( (hour)day/month/year ) to original(mm) ------------------------------- ------------- (04)02/02/2009 - (08)08/05/2009 -50 (09)08/05/2009 - (13)19/04/2010 -100 (14)19/04/2010 - (13)18/08/2011 100 19-31/08/2011 overlap of INOCAR and UHSLC provided level adjustment of 210 mm. In order for the most recent data to be linked to the zero reference, the entire series from 1949-18 Aug 2011 was lowered by 210 mm. The series zero is relative to the UHSLC reference zero beginning 18 Aug 2011. UHSLC Reference level: 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 an apparent trend of about 1.5 cm per year from 1973-1987. This is most likely due to the downward movement of the land relative to the sea. With the exception of the trend, the data agree well with Callao, Peru. However, the data from 5 Jan - 19 Jul 1990 appear about 10 cm low compared to satellite-received redundant data and Baltra data. The originators have investigated this feature and have not found any evidence of a calibration error. The residuals show high-frequency noise in 1998-99. The originators did not detect any problems with the gauge during this period and assume the noise was caused by agitated local seas. Encoder data as noted by * below, were used to fill a few gaps in the 1990-93 data. Bubbler data were used to fill the gap from 09 Feb 2005 - 02 Nov 2005. Comparison of daily means with daily altimeter estimates for the nearshore area show good agreement 1992-2018. There are a few short spans of inconsistency. Notable episodic events: 05-08 Nov 1952: Tsunami from Kamchatka 23-25 May 1960: Tsunami from S.C. Chile 28-29 Mar 1964: Tsunami from Alaska JASL update Nov 2019 replaces Jan 2016 - 05 Sep 2017. CI MISSING REPLACED GAPS QUESTIONABLE YEAR (%) DATA OR BAD DATA FLUCTUATIONS ---- --- -------------------- --------------- -------------------- 1949 33 none none none 1950 98 82-89 (23)121-(22)122 none 1951 100 none (18)365-(23)365 142-145,223-224 1952 100 none none none 1953 98 212-213,219-226 (08)182-(20)182 45-49 (18)191-(15)192 (09)195-(16)195 (06)210-(23)210 (05)211-(19)211 1954 100 none none 7-11,46-48,112-113, 122,257-258,302-303 1955 100 none none none 1956 71 153-159,168-169,176- (04)314-(22)314 86-90,103-104,117- 177,181-226,316-366 118,131-152,161-167 1957 88 1,83-84,159-204 none 19,179-180,284-285 1958 100 none none none 1959 100 none (04)002-(11)002 none (13)002-(20)002 1960 100 none (14)092-(05)093 249 (16)214-(02)215 1961 100 none (15)032-(14)033 none 1962 72 50-154 (10)282-(20)282 none 1963 92 335-365 (17)001-(15)002 none (15)121-(07)122 1964 99 1 (10)259-(03)260 none (05)356-(22)356 1965 100 none none none 1966 100 none none none 1967 100 none (13)117-(02)118 none (21)208-(04)209 (23)209-(20)210 1968 100 none (23)260-(22)261 none 1969 100 none (05)047-(12)047 none (03)120-(11)120 1970 95 133-149,230-233, none 364-365 359-360 1971 87 49-60,86-88,274-305, (15)001-(02)002 10,16-17,25-28,42 322-323,335-336 (09)031-(22)031 102-103,158,177,179- (05)048-(22)048 183,221-223,310 (02)063-(17)063 (11)067-(20)067 (04)068-(20)068 (00)071-(21)071 (05)105-(20)105 (05)110-(20)110 (09)115-(22)115 (09)116-(19)116 (02)334-(18)334 (05)337-(18)337 (05)338-(18)338 1972 93 55-57,79-81, (23)048-(18)049 75-78,81,88-97,201- 179-199,242-244, (16)121-(23)121 202,238-239 (05)153-(19)153 (04)177-(14)177 (05)201-(15)201 (21)212-(18)213 (05)214-(21)214 (20)220-(18)221 (05)306-(16)306 (19)335-(23)335 (01)336-(16)336 (05)351-(14)351 1973 100 none none 19-24,154-155, 161-162 1974 99 232-235 none none 1975 100 none none 177-181,296-297 1976 100 none none 306-310 1977 83 274-337 none 61-63,65-66,245-248, 272-273,345-349,351 1978 98 10-11,304-310 none 112,117-120,123-125, 127-131,137-140,143- 144,168-169,185-189, 204-212,218-220,233- 235,237-239,244-245, 264-267,270-271,295, 318-319 1979 100 none (20)222-(03)223 57,60,65,124,148- 150,283-285,314-315 1980 100 none none 45,107,109,193,269- 270,332 1981 100 none (11)032-(19)032 209,244-249 1982 100 none none 206,210,341 1983 100 none (05)001-(13)001 26,58-60,172-175, 227-228 1984 100 none none 1-2,228-229 1985 100 none none 219-221 1986 100 none (00)236-(06)236 none 1987 100 none (05)274-(11)274 none (03)279-(10)279 1988 100 none none 192-193 1989 100 none (03)040-(12)040 none (05)062-(04)063 (05)069-(04)070 (17)091-(13)092 (05)100-(04)101 (05)121-(04)122 (19)127-(02)128 (05)169-(04)170 (05)312-(04)313 1990 100 none (04)060-(18)060 21,176,237-239,286, *(03)001-(12)003 339-343 1991 100 none (13)090-(04)091 72-73 *(21)020-(07)032 (16)120-(04)121 (05)182-(16)182 (21)273-(04)274 1992 100 none (18)031-(23)031 51-55,96-97,127-128 *(03)245-(09)248 (20)304-(03)305 1993 100 none *(03)101-(23)181 none *(03)209-(14)210 1994 100 none (05)032-(12)032 194-197,362-364 (18)120-(23)120 (00)168-(13)168 (14)181-(23)181 (17)243-(23)243 (16)273-(23)273 (17)304-(23)304 1995 99 26-29,73-74 (04)060-(15)060 none (01)140-(11)140 (02)141-(11)141 (21)243-(23)243 (17)273-(23)273 (17)304-(23)304 1996 100 none (21)061-(23)061 65-82,273-274 (21)091-(23)091 (17)244-(23)244 1997 100 none none none 1998 98 288-291,296-297, (14)004-(22)004 see comment above 304-305 (05)005-(12)005 (02)073-(13)073 (13)094-(22)094 (10)097-(17)097 (05)119-(12)119 (04)123-(12)123 (05)162-(12)162 (21)247-(04)248 (05)284-(04)285 (05)298-(04)299 1999 92 274-283,284-305 none see comment above 2000 88 47-48,63-83,121-122, (05)212-(17)212 1-31 (as in 1998-99) 159-164,166-182,229- (20)212-(04)213 217-219,232-234 230 (05)222-(04)223 (05)226-(04)227 (06)228-(17)228 (05)231-(04)232 2001 98 229-235 none 158-161,198,206,234, 331-332,361 2002 100 none (16)365-(04)001 1-8,12-22,46,157- 158,317-319,344-347 2003 83 305-365 (05)281-(19)281 7-14 (05)283-(14)283 (21)283-(18)284 (21)284-(14)285 (20)285-(13)286 2004 80 1,135-205,273-275 none none 2005 84 306-365 none none 2006 99 1 (16)290-(00)291 none (06)304-(19)304 (23)332-(07)333 2007 100 none (18)276-(16)277 none (15)283-(04)284 2008 99 362-364 (13)235-(12)236 none (14)329-(13)330 2009 100 none (05)212-(04)213 none (05)243-(04)244 2010 100 none none none 2011 96 274-284,287-291 none none 2012 100 none none none 2013 100 none (03)163-(13)163 none (13)174-(00)175 (06)179-(13)179 (04)181-(13)181 (01)182-(13)182 (04)191-(13)191 (23)192-(15)193 (23)193-(14)194 (03)195-(13)195 (03)207-(13)207 2014 100 none none none 2015 100 none none none 2016 92 92-122 (06)058-(15)058 none (23)077-(13)078 (01)079-(13)079 (01)080-(13)080 (04)084-(12)084 (00)086-(13)086 (23)086-(13)087 (00)088-(12)088 (04)089-(13)089 (22)287-(08)288 2017 100 none none none 2018 100 none (21)233-(13)234 none