186SL0678130154201 010A 19741211 19931231 0412S 15211E 2 00000R 0000 MM 186SL0678230154201 Rabaul Papua New Guinea TOGA Sea Level Center 186SL067830001 186SL067830002 QUALITY ASSESSMENT OF SEA LEVEL DATA 186SL067830003 by the 186SL067830004 TOGA SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER 186SL067830005 JOINT ARCHIVE FOR SEA LEVEL 186SL067830006 186SL067830007Station : Rabaul Latitude: 04 12.0S 186SL067830008Country : Papua New Guinea Longitude: 152 10.5E 186SL067830009JASL # : 010A Time Meridian: 150E (GMT + 10 hr) 186SL067830010GLOSS # : 065 TOGA #: P035 NODC #: 30154201 186SL067830011Contributor : TOGA Sea Level Center 186SL067830012 1000 Pope Rd. MSB 317 186SL067830013 Honolulu, Hawaii 96822 186SL067830014Originator : Dept. of Oceanography 186SL067830015 University of Hawaii 186SL067830016 1000 Pope Rd. MSB 317 186SL067830017 Honolulu, Hawaii 96822 186SL067830018Original Data: digital 186SL067830019Instrmnt Type: 1. (1974-present) Leupold and Stevens 186SL067830020 Analog-to-Digital Recorder (ADR); 186SL067830021 2. (10/1984-present) Handar Encoder (ENC) 186SL067830022 Primary gauge: ADR:1974-90, ENC 1991-92 186SL067830023Digitzd Intvl: 15 (ADR), 3 or 4 (ENC) minutes 186SL067830024Present Data : Hourly, daily, and monthly values obtained by: 186SL067830025 Hourly : (pre-1987) Nine-point triangular filter centered 186SL067830026 on the hour with respective periods of the 95, 50, 186SL067830027 and 5% amplitude point of the filter response at 186SL067830028 623.6, 177.0, and 103.7 minutes;(1987+) three-point 186SL067830029 Hanning filter centered on the hour 186SL067830030 Daily : 119-point convolution filter (Bloomfield, 1976) 186SL067830031 centered on noon applied to the hourly data 186SL067830032 with respective periods of the 95, 50, and 5% 186SL067830033 amplitude points at 124.0, 60.2, and 40.2 hours 186SL067830034 Monthly: Simple average of all daily values; calculated if 186SL067830035 7 or fewer days are missing 186SL067830036Span of data : 11 Dec 1974 - 31 Dec 1993 186SL067830037Gaps > 1 mon : none 186SL067830038Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 186SL067830039Units : millimeters Missing Data Flag :99999 186SL067830040Refernce Levl: All heights have been referred to the station tide 186SL067830041 staff zero which is linked to fixed bench marks 186SL067830042Comment : The daily and monthly means reveal no apparent 186SL067830043 changes in the reference level and agree with 186SL067830044 Kapingamarangi. 186SL067830045 186SL067830046 CI MISSING REPLACED GAPS QUESTIONABLE 186SL067830047YEAR (%) DATA OR BAD DATA FLUCTUATIONS 186SL067830048---- --- -------------------- --------------- -------------------- 186SL0678300491974 6 none none none 186SL0678300501975 100 none none none 186SL0678300511976 100 none none none 186SL0678300521977 97 61-63,199-206 (11)059-(05)060 none 186SL0678300531978 97 21-23,99-108 (14)365-(23)365 none 186SL0678300541979 100 none none none 186SL0678300551980 100 none none none 186SL0678300561981 95 178-180,204-208, none none 186SL067830057 211-218,334-335 186SL0678300581982 98 29-34,37-39 none none 186SL0678300591983 100 none none none 186SL0678300601984 100 none none none 186SL0678300611985 100 none none none 186SL0678300621986 100 none none none 186SL0678300631987 100 none none none 186SL0678300641988 99 297-299 none none 186SL0678300651989 100 none none none 186SL0678300661990 100 none none none 186SL0678300671991 99 84-88 none none 186SL0678300681992 100 none none none 186SL0678300691993 100 none none none 186SL067830070 186SL067830071 QUALITY ASSESSMENT POLICY 186SL067830072 186SL067830073 The quality assessment is mostly based on the residuals 186SL067830074 (observed data minus predicted tides) of the hourly data. This 186SL067830075 assessment also applies to the daily and monthly data since 186SL067830076 they were derived from the quality-controlled hourly data. 186SL067830077 186SL067830078 The following abbreviations are used in the assessment: 186SL067830079 JASL - Joint Archive for Sea Level; GLOSS - Global Sea Level 186SL067830080 Observing System; TOGA - Tropical Ocean Global Atmosphere 186SL067830081 research program; NODC - National Oceanographic Data Center; 186SL067830082 Instrmnt - instrument; Digitzd Intvl - digitized interval; 186SL067830083 Gaps > 1 mon - missing data in a span greater than one month; 186SL067830084 Refernce - reference. 186SL067830085 186SL067830086 The following corrections are made to the hourly data 186SL067830087 prior to this assessment: 186SL067830088 1) Gaps or obviously wrong data points in a span less than 186SL067830089 25 hours are filled by the predicted tide method*. 186SL067830090 2) Timing errors of exact increments of an hour are corrected 186SL067830091 by shifting the data. 186SL067830092 3) Reference level shifts are only corrected after information 186SL067830093 from tide staff readings or comparative readings with a fixed 186SL067830094 bench mark are checked to verify that the shift was not a 186SL067830095 natural event. If comparative readings are missing or 186SL067830096 incomplete, comparisons of the data with nearby stations 186SL067830097 may warrant the adjustment of some obvious shifts. 186SL067830098 4) Data with unresolved datum shifts are not disseminated. 186SL067830099 However, if sufficient time spans of data are available before 186SL067830100 or after the year(s) with the unresolved shift(s), a subset of 186SL067830101 quality assured data is made available. Thus, the Span field 186SL067830102 in the Quality Assessment may not match the span of the 186SL067830103 distribution data set. As the questionable datum shifts are 186SL067830104 resolved, the data set will be updated. Although this policy 186SL067830105 adds some complexity, it allows more rapid dissemination of 186SL067830106 at least the quality assured years. 186SL067830107 186SL067830108 For each year, the following information is documented from 186SL067830109 the quality-controlled hourly data with dates given as the nth 186SL067830110 day of the year starting from 1 January: 186SL067830111 1) a Completeness Index (CI) based on the percentage of hours 186SL067830112 with available data, 186SL067830113 2) a list of gaps longer than a day, 186SL067830114 3) a summary of days with consecutive missing or obviously 186SL067830115 wrong data in a time span longer than 6 but less than 25 186SL067830116 hours that have been replaced, with hours in parentheses, and 186SL067830117 4) a summary of days with questionable fluctuations in the 186SL067830118 residual series. Fluctuations within the residuals are 186SL067830119 considered significant and are noted if they are greater than 186SL067830120 25 cm. This policy has changed slightly as of October 1992: 186SL067830121 only suspicious fluctuations due to obvious instrumentation 186SL067830122 problems are noted. Minor timing drifts are no longer 186SL067830123 included in the list of questionable days. 186SL067830124 186SL067830125 Note : If the predicted tides poorly model the observed heights 186SL067830126 due to the inability of the tidal analysis to completely resolv 186SL067830127 the non-linear shallow water effects, the residuals are not 186SL067830128 suitable for assessing the data quality. Instead, a subjective 186SL067830129 comment on the quality of the data is provided. 186SL067830130 186SL067830131 *The predicted tides are obtained with the use of a harmonic 186SL067830132 analysis program (Foreman, 1977) which is executed on a year 186SL067830133 of apparently good data for a given station. The Predicted 186SL067830134 Tide Method for filling gaps consists of statistically 186SL067830135 comparing the predicted tides to the observed data and 186SL067830136 shifting the predicted tides in time to correct for timing 186SL067830137 differences. Then the linear interpolation between hourly 186SL067830138 values at the end points of the gap in the residual series is 186SL067830139 added to the corresponding corrected predicted tide data to 186SL067830140 obtain interpolated values over the span of the gap. 186SL067830141 186SL067830142 Bloomfield, P., 1976. Fourier Analysis of Time Series: An 186SL067830143 Introduction. New York: John Wiley and Sons. pp 129-137. 186SL067830144 186SL067830145 Foreman, M., 1977. Manual For Tidal Height Analysis and 186SL067830146 Prediction. Institute of Ocean Sciences, Patricia Bay, 186SL067830147 Victoria B.C. Pacific Marine Science Report 77-10. 186SL067830148 186SL06786 19741 999999999999999999999999999999999999999999999999 186SL06786 19742 999999999999999999999999999999999999999999999999 186SL06786 19751 845000 866000 932000 945000 889000 876000 186SL06786 19752 842000 866000 887000 925000 952000 927000 186SL06786 19761 973000 948000 920000 908000 850000 820000 186SL06786 19762 790000 740000 754000 796000 848000 877000 186SL06786 19771 801000 867000 908030 895000 830000 785000 186SL06786 19772 99999999 717000 723000 766000 793000 753000 186SL06786 19781 710030 689000 76300099999999 829000 807000 186SL06786 19782 819000 822000 821000 838000 855000 778000 186SL06786 19791 766000 740000 813000 821000 798000 763000 186SL06786 19792 736000 688000 714000 770000 761000 768000 186SL06786 19801 772000 802000 854000 760000 742000 735000 186SL06786 19802 728000 740000 779000 799000 814000 787000 186SL06786 19811 804000 827000 794000 809000 775000 784030 186SL06786 19812 780070 741060 789000 810000 838010 839020 186SL06786 19821 800030 847060 871000 803000 777000 755000 186SL06786 19822 680000 653000 629000 628000 612000 581000 186SL06786 19831 603000 623000 629000 658000 641000 605000 186SL06786 19832 564000 541000 585000 634000 701000 701000 186SL06786 19841 750000 822000 838000 816000 789000 743000 186SL06786 19842 675000 684000 689000 756000 749000 811000 186SL06786 19851 786000 844000 854000 875000 843000 817000 186SL06786 19852 784000 766000 815000 822000 813000 778000 186SL06786 19861 799000 814000 868000 890000 815000 756000 186SL06786 19862 738000 720000 705000 706000 754000 680000 186SL06786 19871 630000 698000 700000 655000 643000 590000 186SL06786 19872 569000 565000 575000 604000 681000 701000 186SL06786 19881 702000 734000 795000 827000 785000 773000 186SL06786 19882 783000 787000 809000 837020 877000 913000 186SL06786 19891 880000 933000 926000 920000 865000 800000 186SL06786 19892 795000 800000 810000 827000 854000 799000 186SL06786 19901 797000 745000 768000 750000 785000 796000 186SL06786 19902 760000 754000 762000 787000 855000 792000 186SL06786 19911 749000 820000 889050 825000 793000 737000 186SL06786 19912 747000 756000 716000 751000 765000 698000 186SL06786 19921 641000 619000 642000 646000 599000 599000 186SL06786 19922 605000 614000 639000 725000 737000 722000 186SL06786 19931 665000 701000 692000 702000 659000 660000 186SL06786 19932 649000 593000 630000 679000 720000 741000