186SL0936172071601 244A 19850101 19921231 2107N 07607W 2 00000R 0000 MM 186SL0936272071601 Gibara Cuba Inst. Cubano De Hidrografia 186SL093630001 186SL093630002 QUALITY ASSESSMENT OF SEA LEVEL DATA 186SL093630003 by the 186SL093630004 TOGA SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER 186SL093630005 JOINT ARCHIVE FOR SEA LEVEL 186SL093630006 186SL093630007Station : Gibara Latitude: 21 07.0N 186SL093630008Country : Cuba Longitude: 076 07.0W 186SL093630009JASL # : 244A Time Meridian: 075W (GMT - 5 hr) 186SL093630010GLOSS # : 276 TOGA #: A003 NODC #: 72071601 186SL093630011Contributor : Instituto Cubano De Hidrografia 186SL093630012 Seccion de Mareas 186SL093630013 3ra. y 4. Miramar 186SL093630014 Ciudad Habana 186SL093630015 CUBA 186SL093630016Originator : same 186SL093630017Original Data: unconfirmed (analog?) 186SL093630018Instrmnt Type: Float and stilling well; model unconfirmed 186SL093630019Digitzd Intvl: unconfirmed (hourly?) 186SL093630020Present Data : Hourly, daily, and monthly values obtained by: 186SL093630021 Hourly : unconfirmed (discrete sampling on the hour?) 186SL093630022 Daily : 119-point convolution filter (Bloomfield, 1976) 186SL093630023 centered on noon applied to the hourly data 186SL093630024 with respective periods of the 95, 50, and 5% 186SL093630025 amplitude points at 124.0, 60.2, and 40.2 hours 186SL093630026 Monthly: Simple average of all daily values; calculated if 186SL093630027 7 or fewer days are missing 186SL093630028Span of data : 01 Jan 1985 - 31 Dec 1992 186SL093630029Gaps > 1 mon : none 186SL093630030Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 186SL093630031Units : millimeters Missing Data Flag :99999 186SL093630032Refernce Levl: All heights have been referred to the station tide 186SL093630033 staff zero which is linked to fixed bench marks. 186SL093630034 These heights are 92 cm below the National Geodetic 186SL093630035 Datum. 186SL093630036Comment : The daily and monthly values do not show any 186SL093630037 obvious shifts or trends and agree fairly well 186SL093630038 with San Juan, Puerto Rico. 186SL093630039 186SL093630040 CI MISSING REPLACED GAPS QUESTIONABLE 186SL093630041YEAR (%) DATA OR BAD DATA FLUCTUATIONS 186SL093630042---- --- -------------------- --------------- -------------------- 186SL0936300431985 100 none none 244-258 186SL0936300441986 100 none (12)310-(02)311 227-240 186SL093630045 (06)337-(13)337 186SL0936300461987 100 none (12)200-(23)200 305-311 186SL0936300471988 100 none (12)050-(04)051 none 186SL093630048 (20)247-(04)248 186SL093630049 (00)272-(11)272 186SL0936300501989 98 80-88 none 316-318 186SL0936300511990 100 none (12)116-(23)116 173-181,305-307 186SL093630052 (02)183-(11)183 186SL093630053 (00)252-(11)252 186SL093630054 (04)336-(18)336 186SL0936300551991 100 none (22)299-(08)300 32-33,225-235, 186SL093630056 (22)356-(17)357 256-266 186SL0936300571992 100 none (00)083-(07)083 207-213,237-245, 186SL093630058 (22)112-(06)113 186SL093630059 (21)185-(18)186 186SL093630060 (01)289-(21)289 186SL093630061 186SL093630062 QUALITY ASSESSMENT POLICY 186SL093630063 186SL093630064 The quality assessment is mostly based on the residuals 186SL093630065 (observed data minus predicted tides) of the hourly data. This 186SL093630066 assessment also applies to the daily and monthly data since 186SL093630067 they were derived from the quality-controlled hourly data. 186SL093630068 186SL093630069 The following abbreviations are used in the assessment: 186SL093630070 JASL - Joint Archive for Sea Level; GLOSS - Global Sea Level 186SL093630071 Observing System; TOGA - Tropical Ocean Global Atmosphere 186SL093630072 research program; NODC - National Oceanographic Data Center; 186SL093630073 Instrmnt - instrument; Digitzd Intvl - digitized interval; 186SL093630074 Gaps > 1 mon - missing data in a span greater than one month; 186SL093630075 Refernce - reference. 186SL093630076 186SL093630077 The following corrections are made to the hourly data 186SL093630078 prior to this assessment: 186SL093630079 1) Gaps or obviously wrong data points in a span less than 186SL093630080 25 hours are filled by the predicted tide method*. 186SL093630081 2) Timing errors of exact increments of an hour are corrected 186SL093630082 by shifting the data. 186SL093630083 3) Reference level shifts are only corrected after information 186SL093630084 from tide staff readings or comparative readings with a fixed 186SL093630085 bench mark are checked to verify that the shift was not a 186SL093630086 natural event. If comparative readings are missing or 186SL093630087 incomplete, comparisons of the data with nearby stations 186SL093630088 may warrant the adjustment of some obvious shifts. 186SL093630089 4) Data with unresolved datum shifts are not disseminated. 186SL093630090 However, if sufficient time spans of data are available before 186SL093630091 or after the year(s) with the unresolved shift(s), a subset of 186SL093630092 quality assured data is made available. Thus, the Span field 186SL093630093 in the Quality Assessment may not match the span of the 186SL093630094 distribution data set. As the questionable datum shifts are 186SL093630095 resolved, the data set will be updated. Although this policy 186SL093630096 adds some complexity, it allows more rapid dissemination of 186SL093630097 at least the quality assured years. 186SL093630098 186SL093630099 For each year, the following information is documented from 186SL093630100 the quality-controlled hourly data with dates given as the nth 186SL093630101 day of the year starting from 1 January: 186SL093630102 1) a Completeness Index (CI) based on the percentage of hours 186SL093630103 with available data, 186SL093630104 2) a list of gaps longer than a day, 186SL093630105 3) a summary of days with consecutive missing or obviously 186SL093630106 wrong data in a time span longer than 6 but less than 25 186SL093630107 hours that have been replaced, with hours in parentheses, and 186SL093630108 4) a summary of days with questionable fluctuations in the 186SL093630109 residual series. Fluctuations within the residuals are 186SL093630110 considered significant and are noted if they are greater than 186SL093630111 25 cm. This policy has changed slightly as of October 1992: 186SL093630112 only suspicious fluctuations due to obvious instrumentation 186SL093630113 problems are noted. Minor timing drifts are no longer 186SL093630114 included in the list of questionable days. 186SL093630115 186SL093630116 Note : If the predicted tides poorly model the observed heights 186SL093630117 due to the inability of the tidal analysis to completely resolv 186SL093630118 the non-linear shallow water effects, the residuals are not 186SL093630119 suitable for assessing the data quality. Instead, a subjective 186SL093630120 comment on the quality of the data is provided. 186SL093630121 186SL093630122 *The predicted tides are obtained with the use of a harmonic 186SL093630123 analysis program (Foreman, 1977) which is executed on a year 186SL093630124 of apparently good data for a given station. The Predicted 186SL093630125 Tide Method for filling gaps consists of statistically 186SL093630126 comparing the predicted tides to the observed data and 186SL093630127 shifting the predicted tides in time to correct for timing 186SL093630128 differences. Then the linear interpolation between hourly 186SL093630129 values at the end points of the gap in the residual series is 186SL093630130 added to the corresponding corrected predicted tide data to 186SL093630131 obtain interpolated values over the span of the gap. 186SL093630132 186SL093630133 Bloomfield, P., 1976. Fourier Analysis of Time Series: An 186SL093630134 Introduction. New York: John Wiley and Sons. pp 129-137. 186SL093630135 186SL093630136 Foreman, M., 1977. Manual For Tidal Height Analysis and 186SL093630137 Prediction. Institute of Ocean Sciences, Patricia Bay, 186SL093630138 Victoria B.C. Pacific Marine Science Report 77-10. 186SL093630139 186SL09366 19851 930010 923000 934000 981000 995000 978000 186SL09366 19852 1043000 1014000 1066000 1113000 1071000 997000 186SL09366 19861 982000 949000 966000 969000 979000 969000 186SL09366 19862 971000 1027000 1120000 1138000 1088000 1033000 186SL09366 19871 1012000 1020000 969000 917000 928000 939000 186SL09366 19872 970000 1030000 1110000 1108000 1003000 918000 186SL09366 19881 903000 898000 864000 949000 1026000 1053000 186SL09366 19882 1047000 1067000 1071000 1106000 1005000 923000 186SL09366 19891 889000 88400099999999 928000 972000 958000 186SL09366 19892 998000 1096000 1099000 1064000 1000000 955000 186SL09366 19901 910000 894000 862000 885000 916000 964000 186SL09366 19902 1009000 1090000 1126000 1178000 1077000 982000 186SL09366 19911 919000 932000 947000 978000 1037000 1040000 186SL09366 19912 1018000 1092000 1119000 1099000 1042000 929000 186SL09366 19921 955000 957000 938000 984000 1004000 1132000 186SL09366 19922 1075000 1080000 1088000 1140000 1098000 978000