186SL0805172118801 036A 19770723 19851231 2853N 11818W 2 00000R 0000 MM 186SL0805272118801 Guadalupe Mexico CICESE 186SL080530001 186SL080530002 QUALITY ASSESSMENT OF SEA LEVEL DATA 186SL080530003 by the 186SL080530004 TOGA SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER 186SL080530005 JOINT ARCHIVE FOR SEA LEVEL 186SL080530006 186SL080530007Station : Guadalupe Latitude: 28 53.0N 186SL080530008Country : Mexico Longitude: 118 18.0W 186SL080530009JASL # : 036A Time Meridian: 120W (GMT - 8 hr) 186SL080530010GLOSS # : 160 TOGA #: P071 NODC #: 72118801 186SL080530011Contributor : Centro de Investigacion Cientifica 186SL080530012 y de Educacion Superior de Ensenada (CICESE) 186SL080530013 Av. Espinoza No. 843 186SL080530014 APDO. Postal 2732 186SL080530015 Ensenada, Baja California, Mexico 186SL080530016Originator : same 186SL080530017Original Data: analog (SA), digital (ADR) 186SL080530018Instrmnt Type: 1. Standard analog (SA) float gauge (1977-1982), 186SL080530019 2. Fischer and Porter Analog-to-Digital 186SL080530020 Recorder (ADR) model 35C 186SL080530021Digitzd Intvl: hourly (SA), 30 minutes (ADR) 186SL080530022Present Data : Hourly, daily, and monthly values obtained by: 186SL080530023 Hourly : Running mean A2,A2,A3 (Godin,1972) 186SL080530024 Daily : 119-point convolution filter (Bloomfield, 1976) 186SL080530025 centered on noon applied to the hourly data 186SL080530026 with respective periods of the 95, 50, and 5% 186SL080530027 amplitude points at 124.0, 60.2, and 40.2 hours 186SL080530028 Monthly: Simple average of all daily values; calculated if 186SL080530029 7 or fewer days are missing 186SL080530030Span of data : 23 Jul 1977 - 31 Dec 1985 186SL080530031Gaps > 1 mon : 09 Aug 1981 - 25 Sep 1981;01 Feb 1982 - 07 Mar 1982 186SL080530032 15 Feb 1983 - 28 Apr 1983;28 Jul 1983 - 25 Sep 1983 186SL080530033 11 Oct 1983 - 16 Feb 1984;15 Jul 1984 - 09 Oct 1984 186SL080530034 07 Nov 1984 - 27 May 1985;09 Aug 1985 - 25 Sep 1985 186SL080530035 28 Oct 1985 - 08 Dec 1985 186SL080530036Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 186SL080530037Units : millimeters Missing Data Flag :99999 186SL080530038Refernce Levl: The sea level heights are referred to the tide 186SL080530039 staff zero which is linked to fixed bench marks. 186SL080530040Comment : The daily and monthly values do not reveal any 186SL080530041 obvious reference level shifts or trends and 186SL080530042 agree reasonably well with the nearest station, 186SL080530043 Cedros Island, Baja California. The data quality 186SL080530044 decreases after 1980. The station has not been 186SL080530045 in operation since Jan 1986. 186SL080530046 186SL080530047 CI MISSING REPLACED GAPS QUESTIONABLE 186SL080530048YEAR (%) DATA OR BAD DATA FLUCTUATIONS 186SL080530049---- --- -------------------- --------------- -------------------- 186SL0805300501977 44 none (18)301-(03)302 224-230,251-252,257, 186SL080530051 267-272,297-301,316- 186SL080530052 317,324-332,340-343 186SL0805300531978 97 89-97,245-249 (05)230-(14)230 82-85,110-115,138- 186SL080530054 (13)354-(02)355 143,170,231-232,275- 186SL080530055 277,287,301-308,313- 186SL080530056 318,350-352,319-365 186SL0805300571979 99 69-72 (19)001-(02)002 14-21,67-68,72-75, 186SL080530058 (06)022-(02)023 96-107,112-119,208, 186SL080530059 (06)035-(14)035 235,338-339,350-352, 186SL080530060 (19)035-(03)036 362-364 186SL0805300611980 100 none (22)128-(15)129 136,357 186SL0805300621981 86 124-126,140-142, (08)025-(18)025 76-84,89-99,129, 186SL080530063 147-148,221-268 (07)028-(19)028 133-134,195-201,217- 186SL080530064 (08)069-(19)069 220,277-279,281-291, 186SL080530065 (21)073-(06)074 326-333,341-348 186SL080530066 (09)076-(21)076 186SL080530067 (21)093-(07)094 186SL080530068 (08)128-(19)128 186SL080530069 (08)136-(07)137 186SL080530070 (08)138-(07)139 186SL080530071 (22)177-(07)178 186SL080530072 (23)189-(06)190 186SL080530073 (00)277-(08)277 186SL080530074 (22)279-(07)280 186SL080530075 (07)331-(19)331 186SL080530076 (23)342-(06)343 186SL080530077 (19)348-(02)349 186SL080530078 (08)363-(19)363 186SL0805300791982 86 32-66,119-121, (21)143-(10)144 186SL080530080 169-171,199-201, (20)166-(05)167 186SL080530081 261-271 (00)216-(08)216 186SL080530082 (06)224-(19)224 186SL080530083 (00)249-(19)249 186SL080530084 (15)279-(07)280 186SL080530085 (19)282-(06)283 186SL080530086 (23)299-(07)300 186SL080530087 (23)338-(07)339 186SL080530088 (21)347-(07)348 186SL0805300891983 40 46-118,209-268, (00)013-(07)013 9,129-137,202-208 186SL080530090 284-365 (21)128-(08)129 186SL080530091 (18)159-(01)160 186SL0805300921984 46 1-48,61-62, (00)058-(10)058 61,108,133-141, 186SL080530093 66-69,81-82, (07)094-(18)094 162-171,306-310 186SL080530094 98-101,197-283, (15)096-(02)097 186SL080530095 312-366 (00)102-(11)102 186SL080530096 (06)105-(00)106 186SL080530097 (07)107-(19)107 186SL0805300981985 35 1-147,197-199, none 182-186,200,291-293, 186SL080530099 221-268,301-343 360-361 186SL080530100 186SL080530101 QUALITY ASSESSMENT POLICY 186SL080530102 186SL080530103 The quality assessment is mostly based on the residuals 186SL080530104 (observed data minus predicted tides) of the hourly data. This 186SL080530105 assessment also applies to the daily and monthly data since 186SL080530106 they were derived from the quality-controlled hourly data. 186SL080530107 186SL080530108 The following abbreviations are used in the assessment: 186SL080530109 JASL - Joint Archive for Sea Level; GLOSS - Global Sea Level 186SL080530110 Observing System; TOGA - Tropical Ocean Global Atmosphere 186SL080530111 research program; NODC - National Oceanographic Data Center; 186SL080530112 Instrmnt - instrument; Digitzd Intvl - digitized interval; 186SL080530113 Gaps > 1 mon - missing data in a span greater than one month; 186SL080530114 Refernce - reference. 186SL080530115 186SL080530116 The following corrections are made to the hourly data 186SL080530117 prior to this assessment: 186SL080530118 1) Gaps or obviously wrong data points in a span less than 186SL080530119 25 hours are filled by the predicted tide method*. 186SL080530120 2) Timing errors of exact increments of an hour are corrected 186SL080530121 by shifting the data. 186SL080530122 3) Reference level shifts are only corrected after information 186SL080530123 from tide staff readings or comparative readings with a fixed 186SL080530124 bench mark are checked to verify that the shift was not a 186SL080530125 natural event. If comparative readings are missing or 186SL080530126 incomplete, comparisons of the data with nearby stations 186SL080530127 may warrant the adjustment of some obvious shifts. 186SL080530128 4) Data with unresolved datum shifts are not disseminated. 186SL080530129 However, if sufficient time spans of data are available before 186SL080530130 or after the year(s) with the unresolved shift(s), a subset of 186SL080530131 quality assured data is made available. Thus, the Span field 186SL080530132 in the Quality Assessment may not match the span of the 186SL080530133 distribution data set. As the questionable datum shifts are 186SL080530134 resolved, the data set will be updated. Although this policy 186SL080530135 adds some complexity, it allows more rapid dissemination of 186SL080530136 at least the quality assured years. 186SL080530137 186SL080530138 For each year, the following information is documented from 186SL080530139 the quality-controlled hourly data with dates given as the nth 186SL080530140 day of the year starting from 1 January: 186SL080530141 1) a Completeness Index (CI) based on the percentage of hours 186SL080530142 with available data, 186SL080530143 2) a list of gaps longer than a day, 186SL080530144 3) a summary of days with consecutive missing or obviously 186SL080530145 wrong data in a time span longer than 6 but less than 25 186SL080530146 hours that have been replaced, with hours in parentheses, and 186SL080530147 4) a summary of days with questionable fluctuations in the 186SL080530148 residual series. Fluctuations within the residuals are 186SL080530149 considered significant and are noted if they are greater than 186SL080530150 25 cm. This policy has changed slightly as of October 1992: 186SL080530151 only suspicious fluctuations due to obvious instrumentation 186SL080530152 problems are noted. Minor timing drifts are no longer 186SL080530153 included in the list of questionable days. 186SL080530154 186SL080530155 Note : If the predicted tides poorly model the observed heights 186SL080530156 due to the inability of the tidal analysis to completely resolv 186SL080530157 the non-linear shallow water effects, the residuals are not 186SL080530158 suitable for assessing the data quality. Instead, a subjective 186SL080530159 comment on the quality of the data is provided. 186SL080530160 186SL080530161 *The predicted tides are obtained with the use of a harmonic 186SL080530162 analysis program (Foreman, 1977) which is executed on a year 186SL080530163 of apparently good data for a given station. The Predicted 186SL080530164 Tide Method for filling gaps consists of statistically 186SL080530165 comparing the predicted tides to the observed data and 186SL080530166 shifting the predicted tides in time to correct for timing 186SL080530167 differences. Then the linear interpolation between hourly 186SL080530168 values at the end points of the gap in the residual series is 186SL080530169 added to the corresponding corrected predicted tide data to 186SL080530170 obtain interpolated values over the span of the gap. 186SL080530171 186SL080530172 Bloomfield, P., 1976. Fourier Analysis of Time Series: An 186SL080530173 Introduction. New York: John Wiley and Sons. pp 129-137. 186SL080530174 186SL080530175 Foreman, M., 1977. Manual For Tidal Height Analysis and 186SL080530176 Prediction. Institute of Ocean Sciences, Patricia Bay, 186SL080530177 Victoria B.C. Pacific Marine Science Report 77-10. 186SL080530178 186SL08056 19771 999999999999999999999999999999999999999999999999 186SL08056 19772 99999999 2103000 2158000 2123000 2064000 2048000 186SL08056 19781 2050000 2080000 2067020 2080070 2103000 2098000 186SL08056 19782 2107000 2129000 2124050 2110000 2053000 2035000 186SL08056 19791 2078000 2064000 2113040 2086000 2106000 2068000 186SL08056 19792 2119000 2130000 2144000 2133000 2102000 2090000 186SL08056 19801 2092000 2068000 2050000 2027000 2045000 2060000 186SL08056 19802 2077000 2132000 2142000 2065000 1987000 2018000 186SL08056 19811 2042000 2028000 2020000 198800099999999 2107000 186SL08056 19812 22050009999999999999999 1985000 1961000 1961000 186SL08056 19821 195700099999999 1998070 1988020 2020010 2041030 186SL08056 19822 2089020 209900099999999 2095000 2093000 2074000 186SL08056 19831 2024000999999999999999999999999 2030000 2045000 186SL08056 19832 21020409999999999999999999999999999999999999999 186SL08056 19841 999999999999999999999999 2057040 2086000 2133000 186SL08056 19842 999999999999999999999999999999999999999999999999 186SL08056 19851 9999999999999999999999999999999999999999 2093000 186SL08056 19852 20740309999999999999999 21970409999999999999999