186SL0871130156501 048A 19680805 19771231 0611S 15553E 2 00000R 0000 MM 186SL0871230156501 Anewa Bay Papua New Guinea TOGA Sea Level Center 186SL087130001 186SL087130002 QUALITY ASSESSMENT OF SEA LEVEL DATA 186SL087130003 by the 186SL087130004 TOGA SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER 186SL087130005 JOINT ARCHIVE FOR SEA LEVEL 186SL087130006 186SL087130007Station : Anewa Bay Latitude: 06 11.0S 186SL087130008Country : Papua New Guinea Longitude: 155 53.0E 186SL087130009JASL # : 048A Time Meridian: 150E (GMT + 10 hr) 186SL087130010GLOSS # : none TOGA #: none NODC #: 30156501 186SL087130011Contributor : TOGA Sea Level Center 186SL087130012 1000 Pope Rd. MSB 317 186SL087130013 Honolulu, Hawaii 96822 186SL087130014Originator : Bougainville Copper PTY. LTD. 186SL087130015 Panguna, Bougainville 186SL087130016 Papua New Guinea 186SL087130017Original Data: analog 186SL087130018Instrmnt Type: Float and well, Leupold Stevens A35 186SL087130019Digitzd Intvl: one hour 186SL087130020Present Data : Hourly, daily, and monthly values obtained by: 186SL087130021 Hourly : The original digitizing interval was hourly 186SL087130022 Daily : 119-point convolution filter (Bloomfield, 1976) 186SL087130023 centered on noon applied to the hourly data 186SL087130024 with respective periods of the 95, 50, and 5% 186SL087130025 amplitude points at 124.0, 60.2, and 40.2 hours 186SL087130026 Monthly: Simple average of all daily values; calculated if 186SL087130027 7 or fewer days are missing 186SL087130028Span of data : 05 Aug 1968 - 31 Dec 1977 186SL087130029Gaps > 1 mon : 20 Oct 1968 - 30 May 1969;16 Feb - 16 Mar 1977 186SL087130030Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 186SL087130031Units : millimeters Missing Data Flag :99999 186SL087130032Refernce Levl: All data are referred to a historic fixed 186SL087130033 bench mark 186SL087130034Comment : The timing is of poor quality. Otherwise the daily 186SL087130035 and monthly values appear reasonable with no 186SL087130036 obvious reference level shifts or trends. The site 186SL087130037 was discontinued in 1977. 186SL087130038 186SL087130039 CI MISSING REPLACED GAPS QUESTIONABLE 186SL087130040YEAR (%) DATA OR BAD DATA FLUCTUATIONS 186SL087130041---- --- -------------------- --------------- -------------------- 186SL0871300421968 21 295-366 none none 186SL0871300431969 58 1-150,201-202, none none 186SL087130044 250-251 186SL0871300451970 100 none none none 186SL0871300461971 95 28-33,73-85 none none 186SL0871300471972 93 28-38,129-133, (01)117-(20)117 278-281 186SL087130048 195-198,209-216 (08)174-(17)174 186SL087130049 (09)206-(06)207 186SL087130050 (17)311-(09)312 186SL0871300511973 93 19-20,86-89,232-236, (01)022-(11)022 21 186SL087130052 250-264,320-325 (07)050-(18)050 186SL0871300531974 72 6-16,37-44,63-77, (01)029-(09)029 none 186SL087130054 157-164,173-186,202- 186SL087130055 224,321-326,342-365 186SL0871300561975 86 1-10,13-20,24-28, (00)315-(11)315 328-331 186SL087130057 286-314,325-328 186SL0871300581976 90 89-90,115-124, (00)260-(23)260 none 186SL087130059 208-232,270-272 186SL0871300601977 88 32-39,47-75, none none 186SL087130061 305-313,365 186SL087130062 186SL087130063 QUALITY ASSESSMENT POLICY 186SL087130064 186SL087130065 The quality assessment is mostly based on the residuals 186SL087130066 (observed data minus predicted tides) of the hourly data. This 186SL087130067 assessment also applies to the daily and monthly data since 186SL087130068 they were derived from the quality-controlled hourly data. 186SL087130069 186SL087130070 The following abbreviations are used in the assessment: 186SL087130071 JASL - Joint Archive for Sea Level; GLOSS - Global Sea Level 186SL087130072 Observing System; TOGA - Tropical Ocean Global Atmosphere 186SL087130073 research program; NODC - National Oceanographic Data Center; 186SL087130074 Instrmnt - instrument; Digitzd Intvl - digitized interval; 186SL087130075 Gaps > 1 mon - missing data in a span greater than one month; 186SL087130076 Refernce - reference. 186SL087130077 186SL087130078 The following corrections are made to the hourly data 186SL087130079 prior to this assessment: 186SL087130080 1) Gaps or obviously wrong data points in a span less than 186SL087130081 25 hours are filled by the predicted tide method*. 186SL087130082 2) Timing errors of exact increments of an hour are corrected 186SL087130083 by shifting the data. 186SL087130084 3) Reference level shifts are only corrected after information 186SL087130085 from tide staff readings or comparative readings with a fixed 186SL087130086 bench mark are checked to verify that the shift was not a 186SL087130087 natural event. If comparative readings are missing or 186SL087130088 incomplete, comparisons of the data with nearby stations 186SL087130089 may warrant the adjustment of some obvious shifts. 186SL087130090 4) Data with unresolved datum shifts are not disseminated. 186SL087130091 However, if sufficient time spans of data are available before 186SL087130092 or after the year(s) with the unresolved shift(s), a subset of 186SL087130093 quality assured data is made available. Thus, the Span field 186SL087130094 in the Quality Assessment may not match the span of the 186SL087130095 distribution data set. As the questionable datum shifts are 186SL087130096 resolved, the data set will be updated. Although this policy 186SL087130097 adds some complexity, it allows more rapid dissemination of 186SL087130098 at least the quality assured years. 186SL087130099 186SL087130100 For each year, the following information is documented from 186SL087130101 the quality-controlled hourly data with dates given as the nth 186SL087130102 day of the year starting from 1 January: 186SL087130103 1) a Completeness Index (CI) based on the percentage of hours 186SL087130104 with available data, 186SL087130105 2) a list of gaps longer than a day, 186SL087130106 3) a summary of days with consecutive missing or obviously 186SL087130107 wrong data in a time span longer than 6 but less than 25 186SL087130108 hours that have been replaced, with hours in parentheses, and 186SL087130109 4) a summary of days with questionable fluctuations in the 186SL087130110 residual series. Fluctuations within the residuals are 186SL087130111 considered significant and are noted if they are greater than 186SL087130112 25 cm. This policy has changed slightly as of October 1992: 186SL087130113 only suspicious fluctuations due to obvious instrumentation 186SL087130114 problems are noted. Minor timing drifts are no longer 186SL087130115 included in the list of questionable days. 186SL087130116 186SL087130117 Note : If the predicted tides poorly model the observed heights 186SL087130118 due to the inability of the tidal analysis to completely resolv 186SL087130119 the non-linear shallow water effects, the residuals are not 186SL087130120 suitable for assessing the data quality. Instead, a subjective 186SL087130121 comment on the quality of the data is provided. 186SL087130122 186SL087130123 *The predicted tides are obtained with the use of a harmonic 186SL087130124 analysis program (Foreman, 1977) which is executed on a year 186SL087130125 of apparently good data for a given station. The Predicted 186SL087130126 Tide Method for filling gaps consists of statistically 186SL087130127 comparing the predicted tides to the observed data and 186SL087130128 shifting the predicted tides in time to correct for timing 186SL087130129 differences. Then the linear interpolation between hourly 186SL087130130 values at the end points of the gap in the residual series is 186SL087130131 added to the corresponding corrected predicted tide data to 186SL087130132 obtain interpolated values over the span of the gap. 186SL087130133 186SL087130134 Bloomfield, P., 1976. Fourier Analysis of Time Series: An 186SL087130135 Introduction. New York: John Wiley and Sons. pp 129-137. 186SL087130136 186SL087130137 Foreman, M., 1977. Manual For Tidal Height Analysis and 186SL087130138 Prediction. Institute of Ocean Sciences, Patricia Bay, 186SL087130139 Victoria B.C. Pacific Marine Science Report 77-10. 186SL087130140 186SL08716 19681 999999999999999999999999999999999999999999999999 186SL08716 19682 99999999 916050 975000999999999999999999999999 186SL08716 19691 9999999999999999999999999999999999999999 872000 186SL08716 19692 833020 771000 753020 735000 776000 768000 186SL08716 19701 702000 771000 840000 870000 883000 833000 186SL08716 19702 815000 848000 832000 859000 864000 887000 186SL08716 19711 901040 96402099999999 997000 930000 895000 186SL08716 19712 902000 863000 877000 907000 903000 863000 186SL08716 19721 796040 850070 877000 878000 818050 715000 186SL08716 19722 99999999 700030 661000 664000 676000 572000 186SL08716 19731 545020 551000 703040 878000 811000 803000 186SL08716 19732 798000 81705099999999 822000 814060 823000 186SL08716 19741 999999999999999999999999 916000 85600099999999 186SL08716 19742 9999999999999999 844000 858000 90206099999999 186SL08716 19751 99999999 839000 916000 932000 893000 889000 186SL08716 19752 880000 885000 9150009999999999999999 962000 186SL08716 19761 947000 922000 908020 854070 859030 806000 186SL08716 19762 76706099999999 799030 855000 873000 823000 186SL08716 19771 7590009999999999999999 875000 859000 805000 186SL08716 19772 714000 720000 695000 69400099999999 673010