186SL0780132114301 167A 19840407 19931231 2453S 11337E 2 00000R 0000 MM 186SL0780232114301 Carnarvon Australia The National Tidal Facility 186SL078030001 186SL078030002 QUALITY ASSESSMENT OF SEA LEVEL DATA 186SL078030003 by the 186SL078030004 TOGA SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER 186SL078030005 JOINT ARCHIVE FOR SEA LEVEL 186SL078030006 186SL078030007Station : Carnarvon Latitude: 24 53.0S 186SL078030008Country : Australia Longitude: 113 37.0E 186SL078030009JASL # : 167A Time Meridian: 120E (GMT + 8 hr) 186SL078030010GLOSS # : 052 TOGA #: I047 NODC #: 32114301 186SL078030011Contributor : The National Tidal Facility 186SL078030012 Flinders University of South Australia 186SL078030013 GPO Box 2100 186SL078030014 Adelaide, 5001, South Australia 186SL078030015 AUSTRALIA 186SL078030016Originator : same 186SL078030017Original Data: analog 186SL078030018Instrmnt Type: Fischer and Porter float/stilling well 186SL078030019Digitzd Intvl: 15 minutes 186SL078030020Present Data : Hourly, daily, and monthly values obtained by: 186SL078030021 Hourly : a raupach filter with half amplitude point of 186SL078030022 0.42 cph 186SL078030023 Daily : 119-point convolution filter (Bloomfield, 1976) 186SL078030024 centered on noon applied to the hourly data 186SL078030025 with respective periods of the 95, 50, and 5% 186SL078030026 amplitude points at 124.0, 60.2, and 40.2 hours 186SL078030027 Monthly: Simple average of all daily values; calculated if 186SL078030028 7 or fewer days are missing 186SL078030029Span of data : 07 Apr 1984 - 31 Dec 1993 186SL078030030Gaps > 1 mon : 13 Oct 1984 - 11 Dec 1984;01 Jan 1985 - 07 Feb 1985 186SL078030031 30 Oct 1985 - 16 Jan 1986;14 Mar 1986 - 15 Aug 1986 186SL078030032 26 Aug 1986 - 07 May 1989;04 Aug 1990 - 24 Sep 1990 186SL078030033Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 186SL078030034Units : millimeters Missing Data Flag :99999 186SL078030035Refernce Levl: The sea level heights are referred to the zero 186SL078030036 point assigned to the tide staff. Bench mark 186SL078030037 information is available upon request from the 186SL078030038 contributors. 186SL078030039Comment : The daily and monthly values are reasonable and 186SL078030040 do not reveal any obvious reference level shifts. 186SL078030041 Some of the questionable fluctuations noted below 186SL078030042 may be associated with meteorological events. 186SL078030043 186SL078030044 SPECIAL NOTE FROM THE DATA CONTRIBUTORS: 186SL078030045 186SL078030046 Supply of sea level data subject to the following 186SL078030047 conditions: 186SL078030048 186SL078030049 i) When any data supplied by the National Tidal 186SL078030050 Facility is used in any publication or report, the 186SL078030051 origin of such data shall be acknowledged in that 186SL078030052 publication or report in the following approved 186SL078030053 form:-- 186SL078030054 186SL078030055 "Tidal {predictions) for {port} {are} supplied 186SL078030056 {constants} {station} {is} 186SL078030057 {material} {...} 186SL078030058 186SL078030059 by the National Tidal Facility, The Flinders 186SL078030060 University of South Australia, Copyright reserved." 186SL078030061 186SL078030062 ii) All material is supplied in good faith and is 186SL078030063 believed to be correct. It is supplied on the 186SL078030064 condition that no warranty is given in relation 186SL078030065 thereto, that no responsibility or liability for 186SL078030066 errors or omissions is, or will be, accepted and 186SL078030067 that the recipient will hold the Flinders Univer- 186SL078030068 sity of South Australia and the National Tidal 186SL078030069 Facility free from all such responsibility or 186SL078030070 liability and from all loss or damage incurred as 186SL078030071 a consequence of any error or omission. 186SL078030072 186SL078030073 iii) The acceptance of material and computations 186SL078030074 from the National Tidal Facility of the Flinders 186SL078030075 University of South Australia will be deemed to 186SL078030076 include acceptance of the conditions of supply. 186SL078030077 186SL078030078 186SL078030079 CI MISSING REPLACED GAPS QUESTIONABLE 186SL078030080YEAR (%) DATA OR BAD DATA FLUCTUATIONS 186SL078030081---- --- -------------------- --------------- -------------------- 186SL0780300821984 56 174-177,287-347 none 123-125,195-208,237- 186SL078030083 247,284-286,347-352, 186SL078030084 354-364 186SL0780300851985 74 1-39,244-256, (02)165-(22)165 47,102-103,194,201, 186SL078030086 289-294,303-365 217-218,238,258-259, 186SL078030087 282,289 186SL0780300881986 18 1-16,73-227 none 23-24,28,43-46,51, 186SL078030089 239-365 225-227 186SL0780300901987 0 1-365 none none 186SL0780300911988 0 1-366 none none 186SL0780300921989 63 1-127,163-173 none none 186SL0780300931990 86 216-267 none none 186SL0780300941991 96 162-164,182-184, none none 186SL078030095 217-226,240-244 186SL0780300961992 100 none none none 186SL0780300971993 100 none none none 186SL078030098 186SL078030099 QUALITY ASSESSMENT POLICY 186SL078030100 186SL078030101 The quality assessment is mostly based on the residuals 186SL078030102 (observed data minus predicted tides) of the hourly data. This 186SL078030103 assessment also applies to the daily and monthly data since 186SL078030104 they were derived from the quality-controlled hourly data. 186SL078030105 186SL078030106 The following abbreviations are used in the assessment: 186SL078030107 JASL - Joint Archive for Sea Level; GLOSS - Global Sea Level 186SL078030108 Observing System; TOGA - Tropical Ocean Global Atmosphere 186SL078030109 research program; NODC - National Oceanographic Data Center; 186SL078030110 Instrmnt - instrument; Digitzd Intvl - digitized interval; 186SL078030111 Gaps > 1 mon - missing data in a span greater than one month; 186SL078030112 Refernce - reference. 186SL078030113 186SL078030114 The following corrections are made to the hourly data 186SL078030115 prior to this assessment: 186SL078030116 1) Gaps or obviously wrong data points in a span less than 186SL078030117 25 hours are filled by the predicted tide method*. 186SL078030118 2) Timing errors of exact increments of an hour are corrected 186SL078030119 by shifting the data. 186SL078030120 3) Reference level shifts are only corrected after information 186SL078030121 from tide staff readings or comparative readings with a fixed 186SL078030122 bench mark are checked to verify that the shift was not a 186SL078030123 natural event. If comparative readings are missing or 186SL078030124 incomplete, comparisons of the data with nearby stations 186SL078030125 may warrant the adjustment of some obvious shifts. 186SL078030126 4) Data with unresolved datum shifts are not disseminated. 186SL078030127 However, if sufficient time spans of data are available before 186SL078030128 or after the year(s) with the unresolved shift(s), a subset of 186SL078030129 quality assured data is made available. Thus, the Span field 186SL078030130 in the Quality Assessment may not match the span of the 186SL078030131 distribution data set. As the questionable datum shifts are 186SL078030132 resolved, the data set will be updated. Although this policy 186SL078030133 adds some complexity, it allows more rapid dissemination of 186SL078030134 at least the quality assured years. 186SL078030135 186SL078030136 For each year, the following information is documented from 186SL078030137 the quality-controlled hourly data with dates given as the nth 186SL078030138 day of the year starting from 1 January: 186SL078030139 1) a Completeness Index (CI) based on the percentage of hours 186SL078030140 with available data, 186SL078030141 2) a list of gaps longer than a day, 186SL078030142 3) a summary of days with consecutive missing or obviously 186SL078030143 wrong data in a time span longer than 6 but less than 25 186SL078030144 hours that have been replaced, with hours in parentheses, and 186SL078030145 4) a summary of days with questionable fluctuations in the 186SL078030146 residual series. Fluctuations within the residuals are 186SL078030147 considered significant and are noted if they are greater than 186SL078030148 25 cm. This policy has changed slightly as of October 1992: 186SL078030149 only suspicious fluctuations due to obvious instrumentation 186SL078030150 problems are noted. Minor timing drifts are no longer 186SL078030151 included in the list of questionable days. 186SL078030152 186SL078030153 Note : If the predicted tides poorly model the observed heights 186SL078030154 due to the inability of the tidal analysis to completely resolv 186SL078030155 the non-linear shallow water effects, the residuals are not 186SL078030156 suitable for assessing the data quality. Instead, a subjective 186SL078030157 comment on the quality of the data is provided. 186SL078030158 186SL078030159 *The predicted tides are obtained with the use of a harmonic 186SL078030160 analysis program (Foreman, 1977) which is executed on a year 186SL078030161 of apparently good data for a given station. The Predicted 186SL078030162 Tide Method for filling gaps consists of statistically 186SL078030163 comparing the predicted tides to the observed data and 186SL078030164 shifting the predicted tides in time to correct for timing 186SL078030165 differences. Then the linear interpolation between hourly 186SL078030166 values at the end points of the gap in the residual series is 186SL078030167 added to the corresponding corrected predicted tide data to 186SL078030168 obtain interpolated values over the span of the gap. 186SL078030169 186SL078030170 Bloomfield, P., 1976. Fourier Analysis of Time Series: An 186SL078030171 Introduction. New York: John Wiley and Sons. pp 129-137. 186SL078030172 186SL078030173 Foreman, M., 1977. Manual For Tidal Height Analysis and 186SL078030174 Prediction. Institute of Ocean Sciences, Patricia Bay, 186SL078030175 Victoria B.C. Pacific Marine Science Report 77-10. 186SL078030176 186SL07806 19841 999999999999999999999999 1085070 1097000 1063030 186SL07806 19842 977000 835000 847000999999999999999999999999 186SL07806 19851 99999999 1117070 921000 1020000 1002000 979000 186SL07806 19852 877000 73300099999999 7050709999999999999999 186SL07806 19861 99999999 90400099999999999999999999999999999999 186SL07806 19862 999999999999999999999999999999999999999999999999 186SL07806 19871 999999999999999999999999999999999999999999999999 186SL07806 19872 999999999999999999999999999999999999999999999999 186SL07806 19881 999999999999999999999999999999999999999999999999 186SL07806 19882 999999999999999999999999999999999999999999999999 186SL07806 19891 99999999999999999999999999999999 106907099999999 186SL07806 19892 908000 826000 800000 741000 827000 794000 186SL07806 19901 928000 969000 929000 908000 923000 873000 186SL07806 19902 8150009999999999999999 712000 738000 807000 186SL07806 19911 779000 859000 872000 1037000 979000 909030 186SL07806 19912 83303099999999 649010 692000 659000 734000 186SL07806 19921 752000 780000 832000 945000 905000 937000 186SL07806 19922 844000 777000 698000 722000 774000 749000 186SL07806 19931 809000 730000 757000 836000 896000 881000 186SL07806 19932 806000 723000 715000 659000 739000 813000