QUALITY ASSESSMENT OF SEA LEVEL DATA by the UH SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER JOINT ARCHIVE FOR SEA LEVEL updated: 24 Jul 2000 Station : Caldera Latitude: 27 04.0S Country : Chile Longitude: 070 50.0W JASL # : 088A Time Meridian: 060W (GMT - 4 hr) GLOSS # : none Originator #:0300 NODC #: 52077001 Contributor : Servicio Hidrografico y Oceanografico de la Armada (SHOA) Casilla 324 Valparaiso CHILE Originator : same Original Data: analog (mechanical,bubbler); digital (encoder) Instrmnt Type: standard mechanical (01/1980 - 12/1985); Metercraft bubbler (12/1985 - present) (primary); Handar Encoder model 436A (11/1986-present) (back- up) Digitzd Intvl: one hour (mechanical,bubbler); 15 min (encoder) 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 (Encoder) 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 1980 - 31 Dec 1999 Gaps > 1 mon : 01 Oct 1981 - 13 Mar 1982 Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 Units : millimeters Missing Data Flag : 9999 Existing : Yes Operational : Yes Sat. Trans. : Yes Distribution : 1980-1998 Refernce Levl: The originators have related the data to tide staff zero which is linked to a fixed set of bench marks. Specifically, BM #1 (established 1950) is used as a historical datum. However, original data as received from SHOA were adjusted with the SHOA station leveling data as follows. value added period( day/month/year ) to original(mm) ------------------------ --------------- 01/01/1980 - 30/09/1981 -366 *03/04/1982 - 07/04/1982 50 *08/04/1982 - 12/04/1982 -150 *16/10/1982 - 19/10/1982 130 19/11/1986 - 22/09/1987 -778 *22/09/1987 - 10/10/1987 -1138 10/10/1987 - 31/12/1987 -778 *Adjustment of shift in reference level deduced from the plot of hourly residuals and from comparison of daily values with Arica and Antofagasta. These adjustments contain uncertainty of a few centimeters. Data from 1988-1989 were received with the reference level tied to the BM #1 (1950) while data for other time periods were received without linking the data to BM #1. Thus, the following level adjustments have been applied to the original data based on SHOA geodetic level records: value added period( day/month/year ) to original(mm) ------------------------ --------------- 01/01/1980 - 31/12/1987 -386 01/01/1990 - 31/12/1992 -1896 01/01/1999 - 28/03/1999 -35 03/28/1999 - 29/08/1999 -1641 29/08/1999 - 31/12/1999 -1284 Level uncertainty in 1999 has these data on hold until clarification can be made by the originators. The corrections for 1999 above were base on assumptions that the satellite-received data at the University of Hawaii maintained proper level. The best available channel for the 1993-98 data is from the Bubbler (BUB) as received via satellite at the University of Hawaii. The data as provided by SHOA was the primary source beginning in 1999. Comment : The daily and monthly values agree well with the nearest stations, Antofagasta and Arica; however, comparison with redundant sensors that transmit data via satellite shows a level shift of about -5 cm on 16 Jan 1989. The original rolls show a tear in the paper which may have caused the problem. However, the originators accept the data as is and thus no corrections have been applied. @ below indicates gaps filled with Encoder data and # below is same for Bubbler data received at the UH Sea Level Center via satellite. & below notes gaps filled with the originators series. CI MISSING REPLACED GAPS QUESTIONABLE YEAR (%) DATA OR BAD DATA FLUCTUATIONS ---- --- -------------------- --------------- -------------------- 1980 98 1,176-182 (23)183-(09)184 22-24,104-105 1981 75 275-365 (00)105-(14)105 none (15)191-(11)192 (14)210-(03)211 1982 80 1-72 (15)152-(11)153 67,71 1983 99 46-49,58-60 (04)101-(23)101 none (00)245-(08)245 1984 100 none (18)023-(11)024 none (18)144-(13)145 (18)169-(13)170 1985 97 1-3,5-7,117-119, (01)001-(13)001 none 145-146 (02)150-(15)150 (19)151-(18)152 (17)175-(13)176 (14)244-(01)245 (06)262-(17)262 (14)274-(01)275 (18)343-(13)344 (16)350-(10)351 (15)361-(13)362 1986 98 301-302,286-292 (01)001-(13)001 333-338 (16)043-(14)044 (05)113-(13)113 1987 100 none (07)058-(14)058 2-3,30-32,222-224, (05)122-(14)122 250-252,277,285-286, (16)159-(15)160 296-300 (03)287-(09)288 (06)292-(13)292 (13)297-(22)297 (01)303-(09)303 (19)304-(13)305 @(00)010-(23)015 #(00)068-(14)086 #(16)282-(20)285 #(20)293-(02)295 #(14)319-(15)320 1988 100 none (22)008-(18)009 none (01)068-(13)068 (14)075-(13)076 (05)087-(13)087 (18)110-(16)111 #(18)214-(18)220 1989 100 none (20)029-(13)030 260-261 (11)188-(22)188 (14)212-(12)213 (20)306-(13)307 (04)344-(22)344 #(16)061-(16)063 #(23)068-(13)070 #(17)273-(12)275 #(05)335-(11)336 #(14)341-(16)342 @(01)363-(23)365 1990 100 none @(00)001-(15)001 none (03)002-(11)002 (19)018-(10)019 @(16)031-(22)046 @(12)053-(11)056 (05)071-(14)071 @(02)072-(13)073 (06)074-(14)074 (21)090-(23)090 (21)105-(13)106 (20)106-(13)107 (08)230-(16)230 (17)365-(23)365 1991 100 none @(16)095-(00)118 137-140,251-255 @(04)151-(15)152 @(20)177-(21)182 @(04)194-(13)196 1992 100 none @(14)111-(17)124 181-182 (18)184-(14)185 (16)205-(13)206 @(20)213-(13)216 (03)238-(13)238 @(21)301-(12)306 (09)336-(16)336 (22)351-(13)352 (04)362-(14)362 1993 100 none @(16)044-(15)047 none @(18)184-(14)187 &(00)247-(23)253 1994 99 67-71 (22)072-(13)073 none (01)082-(13)082 (00)084-(12)084 (22)085-(14)086 (00)087-(14)087 (00)088-(12)088 (21)103-(15)104 (22)104-(14)105 (23)105-(13)106 (23)107-(14)108 (22)108-(15)109 (22)109-(13)110 (03)111-(15)111 (02)112-(16)112 (03)113-(14)113 (03)114-(15)114 (01)115-(15)115 (01)116-(13)116 (00)119-(14)119 (03)120-(14)120 (04)121-(16)121 (22)130-(11)131 (19)316-(11)317 (01)335-(12)335 1995 99 172-173 (02)106-(14)106 180 (01)108-(12)108 (23)108-(11)109 (23)114-(14)115 (22)117-(13)118 (23)122-(12)123 1996 99 156-159 none none 1997 100 none (22)023-(14)025 none (00)042-(13)042 (18)065-(13)066 (23)258-(13)260 1998 100 none (07)300-(13)300 (08)358-(15)358 1999 99 218-219,239-240 (10)086-(09)087 none (12)087-(20)087 (10)089-(09)090 (07)241-(19)241