QUALITY ASSESSMENT OF SEA LEVEL DATA by the UH SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER JOINT ARCHIVE FOR SEA LEVEL updated: 26 May 2017 Station : Lobos de Afuera Latitude: 06 56.0S Country : Peru Longitude: 080 43.0W JASL # : 084A Time Meridian: 075W (GMT - 5 hr) GLOSS # : none Originator #: NODC #: 50086001 Contributor : Direccion Hidrografia y Navegacion de la Marina Camarra 500 Chuculto Casilla Postal 80 Callao, Peru and Atlantic Oceanographic and Meteor. Lab. (AOML) 4301 Rickenbacker Causeway Miami, Florida 33149 Originator : Direccion Hidrografia y Navegacion de la Marina Camarra 500 Chuculto Casilla Postal 80 Callao, Peru Original Data: analog (mechanical); digital (others) Instrmnt Type: 1) standard mechanical tide gauge (1982-2010); 2) Leupold Stevens analog-to-digital recorder (ADR) (5/1985-2007); 3) Handar Encoder (ENC) model 436A (12/1985-2007) 4) 2010- radar Geonica (RGE) Digitzd Intvl: one hour (mechanical); 15 min (ADR); 4 min (ENC,12/85-10/93); 2 min (ENC,11/93-) Present Data : Hourly, daily, and monthly values obtained by: Hourly : The original digitizing interval was hourly (analog); ENC and ADR spot sample on 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 Jul 1982 - 31 Dec 2016 Gaps > 1 mon : 26 Mar - 14 May 1983;01 Jan - 01 Feb 1985; 01 Mar - 01 May 1985;31 Jul - 01 Sep 2007; 26 Aug 2008 - 01 Nov 2008;04 May 2010 - 01 Nov 2012 27 Jan 2015 - 24 Mar 2015 Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 Units : millimeters Missing Data Flag : 9999 Existing : Yes Operational : Yes Sat. Trans. : Yes Distribution : 1982-2016 Refernce Levl: The data which were given to the AOML by the originator contained many reference level shifts. The tide staff comparison readings explained only a few of the shifts. The following shifts were adjusted by the AOML using the comparitive readings, comparisons with the ADR data, and estimations based on the daily values and hourly residuals (observed data minus predicted tides): period value added ( day/month/year ) to original(mm) --------------------- --------------- 14/11/82 - 15/11/82 -150 15/11/82 - 17/11/82 -300 01/06/83 - 10/09/83 -250 11/09/83 - 22/10/83 -130 23/10/83 - 31/12/83 +120 01/01/84 - 31/12/84 +120 18/03/84 - 31/05/84 - 50 12/07/84 - 24/08/84 + 50 01/09/84 - 15/09/84 -300 16/09/84 - 22/09/84 +350 23/09/84 - 30/09/84 -250 20/10/84 - 23/10/84 - 50 01/11/84 - 05/11/84 -200 06/11/84 - 19/11/84 -350 20/11/84 - 30/11/84 -450 01/12/84 - 31/12/84 -300 01/02/85 - 28/02/85 +230 01/05/85 - 28/05/85 +328 01/08/85 - 31/08/85 +328 01/09/85 - 31/09/85 +533 01/10/85 - 31/10/85 +472 01/11/85 - 31/12/85 +625 01/01/86 - 20/01/86 +580 21/01/86 - 31/01/86 +275 01/06/86 - 13/06/86 +350 13/06/86 - 28/06/86 + 40 29/06/86 - 21/07/86 - 60 22/07/86 - 30/09/86 + 40 01/12/86 - 31/12/86 + 60 01/01/87 - 14/06/87 + 55 01/08/87 - 31/08/87 -183 The following level shifts in the analog data were adjusted by JASL based on analysis of the hourly residuals and comparisons with daily data from adjacent stations: Callao, Peru and La Libertad, Ecuador, and with daily data from the ADR and ENC sensors. period value added ( (hour)day/month/year ) to original(mm) --------------------------- --------------- (00)01/07/82 - (05)26/03/83 -110 (06)01/11/83 - (13)21/11/83 - 75 (02)01/12/83 - (18)12/08/84 + 75 (04)01/09/84 - (13)20/11/84 - 70 (05)01/10/87 - (15)16/10/87 -150 (13)11/11/87 - (05)01/12/87 + 60 (06)01/12/87 - (03)16/04/88 - 60 (04)16/04/88 - (16)10/06/88 -100 (17)10/06/88 - (23)11/06/88 -240 (00)12/06/88 - (23)30/09/88 -160 (20)19/02/89 - (18)01/03/89 +75 (12)20/07/89 - (12)19/08/89 +75 (00)02/02/92 - (12)16/02/92 +75 (13)16/02/92 - (08)01/03/92 -120 (00)11/10/93 - (16)01/12/93 80 The above adjustments are uncertain to a few cm. On 19 Sep 2000, the historic JASL data (1982-1994) were adjusted by 160 mm to match the reference level of the originator's data. Due to many suspect level shifts in the ANA data, 01 Feb 2000 to 28 Feb 2001 was replaced by ENC data, which had been adjusted by +210 mm. Comment : This station has a history of reference level shifts. Best guess corrections have been applied yet contain uncertaity. Use with discretion. The following gaps were replaced with data from the redundant sensors, primarily the ENC, which were received via satellite and quality-controlled at the UH Sea Level Center: period ( (hour)day/month/year ) --------------------------- (05)01/03/86 - (10)02/04/86 (00)26/04/86 - (23)31/05/86 (00)26/06/86 - (09)01/07/86 (08)29/10/86 - (09)13/11/86 (00)29/06/87 - (20)01/08/87 (01)01/09/87 - (23)30/09/87 (05)04/10/87 - (11)05/10/87 (00)17/10/87 - (10)19/10/87 (06)10/11/87 - (11)11/11/87 (02)27/02/88 - (21)29/02/88 (00)01/06/88 - (09)02/06/88 (05)01/10/89 - (04)01/11/89 (12)05/04/90 - (04)13/04/90 (00)27/07/91 - (19)14/08/91 (13)26/12/91 - (04)01/02/92 (00)11/11/93 - (23)17/11/93 (00)17/05/94 - (23)25/06/94 (05)01/01/95 - (23)02/01/95 (03)27/09/95 - (23)30/09/95 (00)18/02/97 - (23)07/03/97 (16)21/03/97 - (16)25/03/97 (00)28/06/97 - (04)01/07/97 (00)12/12/97 - (23)14/12/97 (00)19/09/05 - (23)24/10/05 (00)27/02/06 - (04)01/03/06 Based on differences of the data with redundant data received at the UH Sea Level Center via satellite, the accuracy of the daily values appears to be no better than +/- 5 cm. A suspect level shift is seen on 7 May 2001. It is under investigation. CI MISSING REPLACED GAPS QUESTIONABLE YEAR (%) DATA OR BAD DATA FLUCTUATIONS ---- --- -------------------- --------------- -------------------- 1982 46 226-229,274-280, (17)321-(11)322 217,266 324-326,335-341 1983 86 85-134,243-244 none 239-241,251-252,256- 257,260-261,264,294- 296,361-362 1984 89 72-78,153-154, (23)174-(15)175 4-9,22-24,39-40,67- 166-169,173-174, (02)230-(15)230 70,78-81,93-98,136, 175-194,275-287 (01)274-(13)274 139,152,160-161,164, 169,238-239,251,327- 332,343-344,350,355- 356 1985 74 1-32,43-44, none 37,40-43,49-50,52- 60-121 53,123-125,131,155 1986 100 none none 4-6,9-10,12-13,16, 29-30,96-97,258-259 1987 99 269-271 (02)137-(08)137 88,122,138-139,141, (10)208-(16)208 149,151,166-167 (05)305-(12)305 (13)321-(22)321 (02)322-(21)322 (10)340-(04)341 (11)351-(19)351 1988 100 none (05)010-(04)011 none (17)051-(01)052 (17)065-(04)066 (18)117-(00)118 (20)215-(19)216 (03)229-(12)229 (06)237-(23)237 1989 100 none (09)027-(18)027 63-65,160-161 (09)050-(19)050 (03)273-(10)273 1990 100 none (05)168-(04)169 118-119,121-125,130 (20)229-(13)230 (05)276-(14)276 (02)332-(11)332 (13)335-(01)336 (00)345-(11)345 1991 100 none (18)077-(04)078 92-119 (04)182-(11)182 (05)213-(13)213 (20)284-(14)285 (01)305-(12)305 (05)359-(00)360 1992 100 none (13)039-(23)039 81-82,153-182, (21)107-(04)108 212-213 (17)199-(08)200 (22)213-(23)213 (01)214-(08)214 (07)229-(17)229 (05)336-(12)336 1993 100 none none none 1994 100 none (18)135-(02)136 189-191,200-204 1995 99 205-208 (05)032-(14)032 75-80,103-107 (12)041-(23)041 (05)056-(12)056 (04)057-(12)057 (05)091-(16)091 (06)140-(15)140 (02)364-(17)364 1996 99 29-32,152-153 (17)155-(07)156 70 (13)242-(21)242 (23)242-(14)243 1997 100 none (03)137-(12)137 186-189 (02)210-(16)210 (05)278-(12)278 (05)297-(12)297 1998 100 none (18)087-(09)088 126-127,182 (04)120-(11)120 1999 100 none (17)060-(01)061 79-81,317,360-361 (19)061-(04)062 (03)112-(12)112 (22)120-(12)121 (04)173-(13)173 (20)266-(05)267 2000 100 none none none 2001 100 none (05)032-(14)032 none (03)244-(13)244 (20)276-(12)277 2002 100 none (17)016-(02)017 none (05)032-(12)032 (05)060-(13)060 (05)182-(13)182 (05)213-(12)213 (01)294-(11)294 (03)296-(11)296 2003 99 1-2 (03)034-(12)034 294-312 (14)039-(21)039 (01)049-(11)049 (15)058-(11)059 (19)092-(16)093 (04)095-(00)096 (03)111-(17)111 (05)233-(15)233 (18)281-(04)282 (14)285-(23)285 (00)302-(12)302 (12)314-(23)314 (19)317-(12)318 (00)337-(12)337 (14)349-(22)349 2004 99 171-172,197-199 (23)016-(12)017 none (05)038-(12)038 (03)061-(11)061 (12)069-(19)069 (11)095-(18)095 (21)117-(18)118 (22)120-(11)121 (00)124-(12)124 (20)153-(12)154 (06)190-(13)190 (05)228-(14)228 (01)293-(12)293 (03)294-(12)294 (18)294-(01)295 2005 96 102-118 (13)152-(23)152 none (01)153-(13)153 (05)305-(17)305 (05)335-(13)335 2006 97 95-101,151-156 (05)013-(13)013 none (04)105-(12)105 (02)215-(13)215 (17)218-(12)219 (17)273-(04)274 (14)301-(05)302 (10)361-(00)362 2007 81 28-32.79-86,91-104, (02)013-(12)013 none 140-152,212-244,281- (05)015-(12)015 283,300-301 (19)131-(16)132 (01)157-(11)157 (05)170-(12)170 (05)171-(19)171 (01)245-(13)245 (05)276-(12)276 (19)359-(13)360 2008 81 21-24,173-174, (03)068-(13)068 none 189-191,239-306 (11)081-(22)081 (14)088-(23)088 (02)089-(11)089 (23)089-(17)090 (19)091-(11)092 (04)099-(12)099 (05)102-(12)102 (04)104-(12)104 (05)112-(12)112 (14)136-(23)136 (05)155-(15)155 (00)158-(12)158 (07)160-(18)160 (00)171-(12)171 (05)175-(15)175 (00)208-(15)208 (23)230-(13)231 (20)352-(15)353 (04)356-(14)356 2009 99 363-365 (08)038-(17)038 40,56-58,71,150, (17)059-(04)060 175-180,186,203-205, (01)061-(17)061 260-264 (06)063-(16)063 (01)095-(18)095 (04)099-(12)099 (01)117-(13)117 (14)131-(23)131 (14)149-(23)149 (20)150-(03)151 (01)152-(12)152 (01)153-(14)153 (02)156-(12)156 (04)214-(17)214 (20)215-(14)216 (13)218-(20)218 (06)221-(13)221 (01)247-(12)247 (06)275-(17)275 (01)276-(12)276 (21)285-(12)286 (10)287-(17)287 (21)289-(12)290 (15)291-(23)291 (05)293-(12)293 (01)334-(11)334 2010 30 1,42-43,74-76,78-80, (19)096-(09)097 none 85-87,90-94,99-101, (01)117-(09)117 103-105,119-121,124- (04)123-(12)123 365 2011 0 1-365 none none 2012 15 1-306,334-336,363- none 306-363 366 2013 98 1,90-91,120-121,150- (07)031-(05)032 1-31 152,241-244,303-305 (04)059-(03)060 (05)212-(04)213 (13)273-(04)274 (18)324-(16)325 (05)334-(04)335 2014 98 148-152,240-244,303- (13)090-(03)091 none 305 (13)120-(03)121 (19)212-(03)213 2015 84 27-83,241-244 (16)120-(03)121 none (14)181-(03)182 (13)212-(03)213 (18)276-(08)277 2016 99 51-53,190-191, (14)123-(23)123 229-365 350-351 (23)189-(13)190