186SL0695110151401 029A 19780909 19931231 0106N 15447E 2 00000R 0000 MM 186SL0695210151401 Kapingamarangi Fd St Micronesia TOGA Sea Level Center 186SL069530001 186SL069530002 QUALITY ASSESSMENT OF SEA LEVEL DATA 186SL069530003 by the 186SL069530004 TOGA SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER 186SL069530005 JOINT ARCHIVE FOR SEA LEVEL 186SL069530006 186SL069530007Station : Kapingamarangi Latitude: 01 05.9N 186SL069530008Country : Fed. States Micronesia Longitude: 154 46.6E 186SL069530009JASL # : 029A Time Meridian: 165E (GMT + 11 hr) 186SL069530010GLOSS # : 117 TOGA #: P037 NODC #: 10151401 186SL069530011Contributor : TOGA Sea Level Center 186SL069530012 1000 Pope Rd. MSB 317 186SL069530013 Honolulu, Hawaii 96822 186SL069530014Originator : Dept. of Oceanography 186SL069530015 University of Hawaii 186SL069530016 1000 Pope Rd. MSB 317 186SL069530017 Honolulu, Hawaii 96822 186SL069530018Original Data: digital 186SL069530019Instrmnt Type: 1. Leupold and Stevens 186SL069530020 Analog-to-Digital Recorder (ADR); 186SL069530021 2. (Jul 1985-present) Handar Encoder (ENC) 186SL069530022Digitzd Intvl: 15 (ADR); 3 or 4 (ENC) minutes 186SL069530023Present Data : Hourly, daily, and monthly values obtained by: 186SL069530024 Hourly : (pre-1987) Nine-point triangular filter centered 186SL069530025 on the hour with respective periods of the 95, 50, 186SL069530026 and 5% amplitude point of the filter response at 186SL069530027 623.6, 177.0, and 103.7 minutes;(1987+) three-point 186SL069530028 Hanning filter centered on the hour 186SL069530029 Daily : 119-point convolution filter (Bloomfield, 1976) 186SL069530030 centered on noon applied to the hourly data 186SL069530031 with respective periods of the 95, 50, and 5% 186SL069530032 amplitude points at 124.0, 60.2, and 40.2 hours 186SL069530033 Monthly: Simple average of all daily values; calculated if 186SL069530034 7 or fewer days are missing 186SL069530035Span of data : 09 Sep 1978 - 31 Dec 1993 186SL069530036Gaps > 1 mon : 17 Feb - 6 May, 16 Sep - 12 Dec 1980; 30 Mar - 186SL069530037 30 Apr 1981; 30 Oct 1982 - 8 May 1983 186SL069530038Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 186SL069530039Units : millimeters Missing Data Flag :99999 186SL069530040Refernce Levl: All heights have been referred to the station tide 186SL069530041 staff zero which is linked to fixed bench marks 186SL069530042Comment : The daily and monthly means reveal no apparent 186SL069530043 changes in the reference level and agree with 186SL069530044 nearest stations Rabaul and Nauru. The daily means 186SL069530045 and the hourly residuals show significant fluctu- 186SL069530046 ations with a duration of around a day associated 186SL069530047 with westerly winds. The timing accuracy is no 186SL069530048 better than plus or minus 8 minutes prior to 1985. 186SL069530049 Silting around the stilling wells caused question- 186SL069530050 able fluctuations during 1987 - 1990. 186SL069530051 186SL069530052 CI MISSING REPLACED GAPS QUESTIONABLE 186SL069530053YEAR (%) DATA OR BAD DATA FLUCTUATIONS 186SL069530054---- --- -------------------- --------------- -------------------- 186SL0695300551978 31 none none 328-332 186SL0695300561979 90 60-88,179-181, none 348-349 186SL069530057 292-297 186SL0695300581980 49 48-127,136-148, (04)246-(19)246 237-240 186SL069530059 196-198,254-255, 186SL069530060 257-258,260-347 186SL0695300611981 90 89-120,336-337, none none 186SL069530062 359-361 186SL0695300631982 75 86-87,110-119, none 82-85,99-101,127- 186SL069530064 139-147,189-194 128,168-172,229-233, 186SL069530065 303-365 286-287,289-290, 186SL069530066 302-303 186SL0695300671983 65 1-128 none 132-134,194,248-252, 186SL069530068 275-276 186SL0695300691984 100 none none none 186SL0695300701985 97 177-186 none 6-7,54,124-125 186SL0695300711986 99 262-265 none none 186SL0695300721987 98 282-284,288-293 none 29-31,58-62,76-77, 186SL069530073 86-87,104-105,114- 186SL069530074 120,194-195,221-222, 186SL069530075 293-300,305-315, 186SL069530076 319-320 186SL0695300771988 100 none none 22,47-51,63-65,75- 186SL069530078 78,93-96,103-108, 186SL069530079 131-137,159-161,240- 186SL069530080 241,267-270,296-297, 186SL069530081 323-324 186SL0695300821989 100 none none 258-260,328-329 186SL0695300831990 100 none none 69-71,198-199,232- 186SL069530084 236,249-250,261-262, 186SL069530085 289,341,360 186SL0695300861991 100 none none none 186SL0695300871992 100 none none none 186SL0695300881993 100 none none none 186SL069530089 186SL069530090 QUALITY ASSESSMENT POLICY 186SL069530091 186SL069530092 The quality assessment is mostly based on the residuals 186SL069530093 (observed data minus predicted tides) of the hourly data. This 186SL069530094 assessment also applies to the daily and monthly data since 186SL069530095 they were derived from the quality-controlled hourly data. 186SL069530096 186SL069530097 The following abbreviations are used in the assessment: 186SL069530098 JASL - Joint Archive for Sea Level; GLOSS - Global Sea Level 186SL069530099 Observing System; TOGA - Tropical Ocean Global Atmosphere 186SL069530100 research program; NODC - National Oceanographic Data Center; 186SL069530101 Instrmnt - instrument; Digitzd Intvl - digitized interval; 186SL069530102 Gaps > 1 mon - missing data in a span greater than one month; 186SL069530103 Refernce - reference. 186SL069530104 186SL069530105 The following corrections are made to the hourly data 186SL069530106 prior to this assessment: 186SL069530107 1) Gaps or obviously wrong data points in a span less than 186SL069530108 25 hours are filled by the predicted tide method*. 186SL069530109 2) Timing errors of exact increments of an hour are corrected 186SL069530110 by shifting the data. 186SL069530111 3) Reference level shifts are only corrected after information 186SL069530112 from tide staff readings or comparative readings with a fixed 186SL069530113 bench mark are checked to verify that the shift was not a 186SL069530114 natural event. If comparative readings are missing or 186SL069530115 incomplete, comparisons of the data with nearby stations 186SL069530116 may warrant the adjustment of some obvious shifts. 186SL069530117 4) Data with unresolved datum shifts are not disseminated. 186SL069530118 However, if sufficient time spans of data are available before 186SL069530119 or after the year(s) with the unresolved shift(s), a subset of 186SL069530120 quality assured data is made available. Thus, the Span field 186SL069530121 in the Quality Assessment may not match the span of the 186SL069530122 distribution data set. As the questionable datum shifts are 186SL069530123 resolved, the data set will be updated. Although this policy 186SL069530124 adds some complexity, it allows more rapid dissemination of 186SL069530125 at least the quality assured years. 186SL069530126 186SL069530127 For each year, the following information is documented from 186SL069530128 the quality-controlled hourly data with dates given as the nth 186SL069530129 day of the year starting from 1 January: 186SL069530130 1) a Completeness Index (CI) based on the percentage of hours 186SL069530131 with available data, 186SL069530132 2) a list of gaps longer than a day, 186SL069530133 3) a summary of days with consecutive missing or obviously 186SL069530134 wrong data in a time span longer than 6 but less than 25 186SL069530135 hours that have been replaced, with hours in parentheses, and 186SL069530136 4) a summary of days with questionable fluctuations in the 186SL069530137 residual series. Fluctuations within the residuals are 186SL069530138 considered significant and are noted if they are greater than 186SL069530139 25 cm. This policy has changed slightly as of October 1992: 186SL069530140 only suspicious fluctuations due to obvious instrumentation 186SL069530141 problems are noted. Minor timing drifts are no longer 186SL069530142 included in the list of questionable days. 186SL069530143 186SL069530144 Note : If the predicted tides poorly model the observed heights 186SL069530145 due to the inability of the tidal analysis to completely resolv 186SL069530146 the non-linear shallow water effects, the residuals are not 186SL069530147 suitable for assessing the data quality. Instead, a subjective 186SL069530148 comment on the quality of the data is provided. 186SL069530149 186SL069530150 *The predicted tides are obtained with the use of a harmonic 186SL069530151 analysis program (Foreman, 1977) which is executed on a year 186SL069530152 of apparently good data for a given station. The Predicted 186SL069530153 Tide Method for filling gaps consists of statistically 186SL069530154 comparing the predicted tides to the observed data and 186SL069530155 shifting the predicted tides in time to correct for timing 186SL069530156 differences. Then the linear interpolation between hourly 186SL069530157 values at the end points of the gap in the residual series is 186SL069530158 added to the corresponding corrected predicted tide data to 186SL069530159 obtain interpolated values over the span of the gap. 186SL069530160 186SL069530161 Bloomfield, P., 1976. Fourier Analysis of Time Series: An 186SL069530162 Introduction. New York: John Wiley and Sons. pp 129-137. 186SL069530163 186SL069530164 Foreman, M., 1977. Manual For Tidal Height Analysis and 186SL069530165 Prediction. Institute of Ocean Sciences, Patricia Bay, 186SL069530166 Victoria B.C. Pacific Marine Science Report 77-10. 186SL069530167 186SL06956 19781 999999999999999999999999999999999999999999999999 186SL06956 19782 999999999999999999999999 1048000 1152000 993000 186SL06956 19791 959000 91100099999999 992000 947000 918030 186SL06956 19792 951000 955000 929000 1050060 1033000 1081000 186SL06956 19801 99202099999999999999999999999999999999 937000 186SL06956 19802 958030 95800099999999999999999999999999999999 186SL06956 19811 1019000 1031000 98902099999999 918000 911000 186SL06956 19812 936000 965000 962000 1025000 1001000 1101050 186SL06956 19821 1016000 1039000 10640209999999999999999 970000 186SL06956 19822 979060 976000 882000 8710209999999999999999 186SL06956 19831 9999999999999999999999999999999999999999 801000 186SL06956 19832 822000 793000 827000 888000 960000 955000 186SL06956 19841 942000 949000 956000 923000 910000 907000 186SL06956 19842 905000 938000 907000 1012000 1023000 1071000 186SL06956 19851 1105000 1052000 1051000 1034000 1003000 996050 186SL06956 19852 981050 985000 1006000 1010000 1023000 1030000 186SL06956 19861 1011000 1058000 1061000 1039000 1045000 939000 186SL06956 19862 973000 1004000 1002040 948000 1054000 983000 186SL06956 19871 830000 931000 918000 906000 862000 806000 186SL06956 19872 844000 821000 80300099999999 937000 956000 186SL06956 19881 920000 958000 959000 952000 908000 925000 186SL06956 19882 946000 916000 949000 993000 1018000 1067000 186SL06956 19891 1046000 1089000 1089000 1059000 1029000 962000 186SL06956 19892 974000 978000 983000 1025000 1157000 1049000 186SL06956 19901 1046000 975000 1000000 962000 951000 1002000 186SL06956 19902 967000 1030000 976000 1026000 1143000 1041000 186SL06956 19911 967000 992000 1123000 997000 1002000 924000 186SL06956 19912 942000 998000 1025000 1015000 1018000 921000 186SL06956 19921 824000 773000 813000 818000 817000 849000 186SL06956 19922 864000 885000 922000 1017000 1035000 977000 186SL06956 19931 896000 944000 971000 951000 901000 910000 186SL06956 19932 890000 911000 889000 948000 957000 1023000