186SL0779132110801 169A 19840101 19931231 2019S 11834E 2 00000R 0000 MM 186SL0779232110801 Port Hedland Australia The National Tidal Facility 186SL077930001 186SL077930002 QUALITY ASSESSMENT OF SEA LEVEL DATA 186SL077930003 by the 186SL077930004 TOGA SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER 186SL077930005 JOINT ARCHIVE FOR SEA LEVEL 186SL077930006 186SL077930007Station : Port Hedland Latitude: 20 19.0S 186SL077930008Country : Australia Longitude: 118 34.0E 186SL077930009JASL # : 169A Time Meridian: 120E (GMT + 8 hr) 186SL077930010GLOSS # : 051 TOGA #: I046 NODC #: 32110801 186SL077930011Contributor : The National Tidal Facility 186SL077930012 Flinders University of South Australia 186SL077930013 GPO Box 2100 186SL077930014 Adelaide, 5001, South Australia 186SL077930015 AUSTRALIA 186SL077930016Originator : same 186SL077930017Original Data: analog (LS), digital (FP) 186SL077930018Instrmnt Type: Leupold Stevens, Fischer and Porter -- both 186SL077930019 float and stilling well gauges 186SL077930020Digitzd Intvl: 15 minutes 186SL077930021Present Data : Hourly, daily, and monthly values obtained by: 186SL077930022 Hourly : a raupach filter with half amplitude point of 186SL077930023 0.42 cph 186SL077930024 Daily : 119-point convolution filter (Bloomfield, 1976) 186SL077930025 centered on noon applied to the hourly data 186SL077930026 with respective periods of the 95, 50, and 5% 186SL077930027 amplitude points at 124.0, 60.2, and 40.2 hours 186SL077930028 Monthly: Simple average of all daily values; calculated if 186SL077930029 7 or fewer days are missing 186SL077930030Span of data : 01 Jan 1984 - 31 Dec 1993 186SL077930031Gaps > 1 mon : 08 Mar 1984 - 16 Apr 1984;31 Dec 1985 - 02 Apr 1986 186SL077930032Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 186SL077930033Units : millimeters Missing Data Flag :99999 186SL077930034Refernce Levl: The sea level heights are referred to the zero 186SL077930035 point assigned to the tide staff. Bench mark 186SL077930036 information is available upon request from the 186SL077930037 contributors. 186SL077930038Comment : The residuals (observed data minus predicted tides) 186SL077930039 are noisy, probably due to either shallow water and 186SL077930040 complex coastal geometry effects that are not 186SL077930041 resolved by the harmonic analysis or timing errors 186SL077930042 which are not offset by increments of one hour. 186SL077930043 Meteorological events caused large deviations 186SL077930044 during the southern summer. Otherwise, the daily 186SL077930045 and monthly values do not reveal any obvious 186SL077930046 reference level shifts and agree reasonably well 186SL077930047 with the nearest station, Broome. 186SL077930048 186SL077930049 SPECIAL NOTE FROM THE DATA CONTRIBUTORS: 186SL077930050 186SL077930051 Supply of sea level data subject to the following 186SL077930052 conditions: 186SL077930053 186SL077930054 i) When any data supplied by the National Tidal 186SL077930055 Facility is used in any publication or report, the 186SL077930056 origin of such data shall be acknowledged in that 186SL077930057 publication or report in the following approved 186SL077930058 form:-- 186SL077930059 186SL077930060 "Tidal {predictions) for {port} {are} supplied 186SL077930061 {constants} {station} {is} 186SL077930062 {material} {...} 186SL077930063 186SL077930064 by the National Tidal Facility, The Flinders 186SL077930065 University of South Australia, Copyright reserved." 186SL077930066 186SL077930067 ii) All material is supplied in good faith and is 186SL077930068 believed to be correct. It is supplied on the 186SL077930069 condition that no warranty is given in relation 186SL077930070 thereto, that no responsibility or liability for 186SL077930071 errors or omissions is, or will be, accepted and 186SL077930072 that the recipient will hold the Flinders Univer- 186SL077930073 sity of South Australia and the National Tidal 186SL077930074 Facility free from all such responsibility or 186SL077930075 liability and from all loss or damage incurred as 186SL077930076 a consequence of any error or omission. 186SL077930077 186SL077930078 iii) The acceptance of material and computations 186SL077930079 from the National Tidal Facility of the Flinders 186SL077930080 University of South Australia will be deemed to 186SL077930081 include acceptance of the conditions of supply. 186SL077930082 186SL077930083 CI MISSING REPLACED GAPS QUESTIONABLE 186SL077930084YEAR (%) DATA OR BAD DATA FLUCTUATIONS 186SL077930085---- --- -------------------- --------------- -------------------- 186SL0779300861984 79 9-17,68-107, none see comment above 186SL077930087 230-244,257-263, 186SL077930088 303-312 186SL0779300891985 99 365 none see comment above 186SL0779300901986 75 1-92 none see comment above 186SL0779300911987 100 none none see comment above 186SL0779300921988 100 none none see comment above 186SL0779300931989 100 none none see comment above 186SL0779300941990 100 none none see comment above 186SL0779300951991 99 166-170 none see comment above 186SL0779300961992 100 none none see comment above 186SL0779300971993 100 none none see comment above 186SL077930098 186SL077930099 QUALITY ASSESSMENT POLICY 186SL077930100 186SL077930101 The quality assessment is mostly based on the residuals 186SL077930102 (observed data minus predicted tides) of the hourly data. This 186SL077930103 assessment also applies to the daily and monthly data since 186SL077930104 they were derived from the quality-controlled hourly data. 186SL077930105 186SL077930106 The following abbreviations are used in the assessment: 186SL077930107 JASL - Joint Archive for Sea Level; GLOSS - Global Sea Level 186SL077930108 Observing System; TOGA - Tropical Ocean Global Atmosphere 186SL077930109 research program; NODC - National Oceanographic Data Center; 186SL077930110 Instrmnt - instrument; Digitzd Intvl - digitized interval; 186SL077930111 Gaps > 1 mon - missing data in a span greater than one month; 186SL077930112 Refernce - reference. 186SL077930113 186SL077930114 The following corrections are made to the hourly data 186SL077930115 prior to this assessment: 186SL077930116 1) Gaps or obviously wrong data points in a span less than 186SL077930117 25 hours are filled by the predicted tide method*. 186SL077930118 2) Timing errors of exact increments of an hour are corrected 186SL077930119 by shifting the data. 186SL077930120 3) Reference level shifts are only corrected after information 186SL077930121 from tide staff readings or comparative readings with a fixed 186SL077930122 bench mark are checked to verify that the shift was not a 186SL077930123 natural event. If comparative readings are missing or 186SL077930124 incomplete, comparisons of the data with nearby stations 186SL077930125 may warrant the adjustment of some obvious shifts. 186SL077930126 4) Data with unresolved datum shifts are not disseminated. 186SL077930127 However, if sufficient time spans of data are available before 186SL077930128 or after the year(s) with the unresolved shift(s), a subset of 186SL077930129 quality assured data is made available. Thus, the Span field 186SL077930130 in the Quality Assessment may not match the span of the 186SL077930131 distribution data set. As the questionable datum shifts are 186SL077930132 resolved, the data set will be updated. Although this policy 186SL077930133 adds some complexity, it allows more rapid dissemination of 186SL077930134 at least the quality assured years. 186SL077930135 186SL077930136 For each year, the following information is documented from 186SL077930137 the quality-controlled hourly data with dates given as the nth 186SL077930138 day of the year starting from 1 January: 186SL077930139 1) a Completeness Index (CI) based on the percentage of hours 186SL077930140 with available data, 186SL077930141 2) a list of gaps longer than a day, 186SL077930142 3) a summary of days with consecutive missing or obviously 186SL077930143 wrong data in a time span longer than 6 but less than 25 186SL077930144 hours that have been replaced, with hours in parentheses, and 186SL077930145 4) a summary of days with questionable fluctuations in the 186SL077930146 residual series. Fluctuations within the residuals are 186SL077930147 considered significant and are noted if they are greater than 186SL077930148 25 cm. This policy has changed slightly as of October 1992: 186SL077930149 only suspicious fluctuations due to obvious instrumentation 186SL077930150 problems are noted. Minor timing drifts are no longer 186SL077930151 included in the list of questionable days. 186SL077930152 186SL077930153 Note : If the predicted tides poorly model the observed heights 186SL077930154 due to the inability of the tidal analysis to completely resolv 186SL077930155 the non-linear shallow water effects, the residuals are not 186SL077930156 suitable for assessing the data quality. Instead, a subjective 186SL077930157 comment on the quality of the data is provided. 186SL077930158 186SL077930159 *The predicted tides are obtained with the use of a harmonic 186SL077930160 analysis program (Foreman, 1977) which is executed on a year 186SL077930161 of apparently good data for a given station. The Predicted 186SL077930162 Tide Method for filling gaps consists of statistically 186SL077930163 comparing the predicted tides to the observed data and 186SL077930164 shifting the predicted tides in time to correct for timing 186SL077930165 differences. Then the linear interpolation between hourly 186SL077930166 values at the end points of the gap in the residual series is 186SL077930167 added to the corresponding corrected predicted tide data to 186SL077930168 obtain interpolated values over the span of the gap. 186SL077930169 186SL077930170 Bloomfield, P., 1976. Fourier Analysis of Time Series: An 186SL077930171 Introduction. New York: John Wiley and Sons. pp 129-137. 186SL077930172 186SL077930173 Foreman, M., 1977. Manual For Tidal Height Analysis and 186SL077930174 Prediction. Institute of Ocean Sciences, Patricia Bay, 186SL077930175 Victoria B.C. Pacific Marine Science Report 77-10. 186SL077930176 186SL07796 19841 99999999 42130009999999999999999 4282000 4189000 186SL07796 19842 408500099999999 4104070 4143030 4176070 4195000 186SL07796 19851 4193000 4300000 4235000 4300000 4224000 4155000 186SL07796 19852 4084000 4030000 4054000 3997000 4058000 4062010 186SL07796 19861 999999999999999999999999 4297020 4171000 4206000 186SL07796 19862 4062000 4010000 4028000 4027000 4105000 4103000 186SL07796 19871 4145000 4139000 4159000 4191000 4114000 4083000 186SL07796 19872 4062000 3990000 3991000 3986000 4036000 4101000 186SL07796 19881 4159000 4192000 4274000 4245000 4251000 4183000 186SL07796 19882 4102000 4102000 4130000 4207000 4233000 4288000 186SL07796 19891 4294000 4356000 4360000 4360000 4249000 4218000 186SL07796 19892 4142000 4113000 4119000 4150000 4172000 4168000 186SL07796 19901 4283000 4228000 4211000 4191000 4174000 4106000 186SL07796 19902 4010000 4036000 4058000 4051000 4130000 4153000 186SL07796 19911 4160000 4184000 4185000 4262000 4146000 4079050 186SL07796 19912 4042000 3996000 3948000 4048000 4036000 4093000 186SL07796 19921 4048000 4083000 4133000 4191000 4137000 4130000 186SL07796 19922 4054000 3990000 3981000 4068000 4089000 4066000 186SL07796 19931 4137000 4081000 4113000 4171000 4146000 4095000 186SL07796 19932 3991000 3946000 3977000 3997000 4064000 4154010