186SL0961113115901 642A 19750101 19901231 3523N 11933E 2 00000R 0000 MM 186SL0961213115901 Shijiusuo China PRC Nat. Ocean. Data Center 186SL096130001 186SL096130002 QUALITY ASSESSMENT OF SEA LEVEL DATA 186SL096130003 by the 186SL096130004 TOGA SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER 186SL096130005 JOINT ARCHIVE FOR SEA LEVEL 186SL096130006 186SL096130007Station : Shijiusuo Latitude: 35 23.0N 186SL096130008Country : China Longitude: 119 33.0E 186SL096130009JASL # : 642A Time Meridian: 120E (GMT + 8 hr) 186SL096130010GLOSS # : none TOGA #: none NODC #: 13115901 186SL096130011Contributor : PRC National Oceanographic Data Center 186SL096130012 118, Qiwei Road, Hedong 186SL096130013 District Tianjin, China 186SL096130014Originator : same 186SL096130015Original Data: analog 186SL096130016Instrmnt Type: float and well; HCJ1 (1975-85); SCA1-1 (1986-90) 186SL096130017Digitzd Intvl: hourly 186SL096130018Present Data : Hourly, daily, and monthly values obtained by: 186SL096130019 Hourly : spot hourly 186SL096130020 Daily : 119-point convolution filter (Bloomfield, 1976) 186SL096130021 centered on noon applied to the hourly data 186SL096130022 with respective periods of the 95, 50, and 5% 186SL096130023 amplitude points at 124.0, 60.2, and 40.2 hours 186SL096130024 Monthly: Simple average of all daily values; calculated if 186SL096130025 7 or fewer days are missing 186SL096130026Span of data : 01 Jan 1975 - 31 Dec 1990 186SL096130027Gaps > 1 mon : 30 Nov - 31 Dec 1983 186SL096130028Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 186SL096130029Units : millimeters Missing Data Flag :99999 186SL096130030Refernce Levl: The sea level heights are referred to the zero 186SL096130031 point assigned to the tide gauge. Bench mark 186SL096130032 information is available upon request from the 186SL096130033 contributors. 186SL096130034Comment : The residual series are very noisy which are 186SL096130035 probably due to shallow water tides that are not 186SL096130036 resolved by the harmonic analysis. Also the daily 186SL096130037 plot shows noise due to a great amount of energy 186SL096130038 with periods from 1 to 5 days. 186SL096130039 186SL096130040 CI MISSING REPLACED GAPS QUESTIONABLE 186SL096130041YEAR (%) DATA OR BAD DATA FLUCTUATIONS 186SL096130042---- --- -------------------- --------------- -------------------- 186SL0961300431975 100 none none see comment above 186SL0961300441976 100 none (15)174-(23)174 see comment above 186SL0961300451977 100 none (02)002-(09)002 see comment above 186SL096130046 (16)005-(23)005 186SL096130047 (15)214-(23)214 186SL0961300481978 100 none (13)006-(23)006 see comment above 186SL0961300491979 100 none (13)028-(23)028 see comment above 186SL096130050 (01)029-(12)029 186SL096130051 (15)029-(00)030 186SL096130052 (13)207-(23)207 186SL096130053 (13)317-(23)317 186SL0961300541980 100 none (14)040-(23)040 see comment above 186SL096130055 (14)257-(23)257 186SL0961300561981 100 none (13)004-(23)004 see comment above 186SL096130057 (14)023-(22)023 186SL096130058 (13)126-(23)126 186SL096130059 (13)156-(23)156 186SL096130060 (16)250-(23)250 186SL0961300611982 100 none (13)185-(23)185 see comment above 186SL096130062 (15)239-(23)239 186SL096130063 (15)255-(23)255 186SL096130064 (14)263-(23)263 186SL096130065 (16)300-(23)300 186SL096130066 (16)309-(23)309 186SL0961300671983 92 334-365 (15)006-(23)006 see comment above 186SL096130068 (13)007-(23)007 186SL096130069 (16)208-(23)208 186SL0961300701984 100 none (16)321-(23)321 see comment above 186SL096130071 (01)336-(11)336 186SL0961300721985 100 none (16)282-(23)282 see comment above 186SL0961300731986 100 none (16)303-(23)303 see comment above 186SL096130074 (16)337-(23)337 186SL0961300751987 100 none none see comment above 186SL0961300761988 100 none (14)251-(23)251 see comment above 186SL0961300771989 100 none (16)276-(23)276 see comment above 186SL096130078 (13)318-(23)318 186SL096130079 (15)323-(23)323 186SL096130080 (16)324-(23)324 186SL096130081 (15)348-(23)348 186SL0961300821990 99 365 none see comment above 186SL096130083 186SL096130084 QUALITY ASSESSMENT POLICY 186SL096130085 186SL096130086 The quality assessment is mostly based on the residuals 186SL096130087 (observed data minus predicted tides) of the hourly data. This 186SL096130088 assessment also applies to the daily and monthly data since 186SL096130089 they were derived from the quality-controlled hourly data. 186SL096130090 186SL096130091 The following abbreviations are used in the assessment: 186SL096130092 JASL - Joint Archive for Sea Level; GLOSS - Global Sea Level 186SL096130093 Observing System; TOGA - Tropical Ocean Global Atmosphere 186SL096130094 research program; NODC - National Oceanographic Data Center; 186SL096130095 Instrmnt - instrument; Digitzd Intvl - digitized interval; 186SL096130096 Gaps > 1 mon - missing data in a span greater than one month; 186SL096130097 Refernce - reference. 186SL096130098 186SL096130099 The following corrections are made to the hourly data 186SL096130100 prior to this assessment: 186SL096130101 1) Gaps or obviously wrong data points in a span less than 186SL096130102 25 hours are filled by the predicted tide method*. 186SL096130103 2) Timing errors of exact increments of an hour are corrected 186SL096130104 by shifting the data. 186SL096130105 3) Reference level shifts are only corrected after information 186SL096130106 from tide staff readings or comparative readings with a fixed 186SL096130107 bench mark are checked to verify that the shift was not a 186SL096130108 natural event. If comparative readings are missing or 186SL096130109 incomplete, comparisons of the data with nearby stations 186SL096130110 may warrant the adjustment of some obvious shifts. 186SL096130111 4) Data with unresolved datum shifts are not disseminated. 186SL096130112 However, if sufficient time spans of data are available before 186SL096130113 or after the year(s) with the unresolved shift(s), a subset of 186SL096130114 quality assured data is made available. Thus, the Span field 186SL096130115 in the Quality Assessment may not match the span of the 186SL096130116 distribution data set. As the questionable datum shifts are 186SL096130117 resolved, the data set will be updated. Although this policy 186SL096130118 adds some complexity, it allows more rapid dissemination of 186SL096130119 at least the quality assured years. 186SL096130120 186SL096130121 For each year, the following information is documented from 186SL096130122 the quality-controlled hourly data with dates given as the nth 186SL096130123 day of the year starting from 1 January: 186SL096130124 1) a Completeness Index (CI) based on the percentage of hours 186SL096130125 with available data, 186SL096130126 2) a list of gaps longer than a day, 186SL096130127 3) a summary of days with consecutive missing or obviously 186SL096130128 wrong data in a time span longer than 6 but less than 25 186SL096130129 hours that have been replaced, with hours in parentheses, and 186SL096130130 4) a summary of days with questionable fluctuations in the 186SL096130131 residual series. Fluctuations within the residuals are 186SL096130132 considered significant and are noted if they are greater than 186SL096130133 25 cm. This policy has changed slightly as of October 1992: 186SL096130134 only suspicious fluctuations due to obvious instrumentation 186SL096130135 problems are noted. Minor timing drifts are no longer 186SL096130136 included in the list of questionable days. 186SL096130137 186SL096130138 Note : If the predicted tides poorly model the observed heights 186SL096130139 due to the inability of the tidal analysis to completely resolv 186SL096130140 the non-linear shallow water effects, the residuals are not 186SL096130141 suitable for assessing the data quality. Instead, a subjective 186SL096130142 comment on the quality of the data is provided. 186SL096130143 186SL096130144 *The predicted tides are obtained with the use of a harmonic 186SL096130145 analysis program (Foreman, 1977) which is executed on a year 186SL096130146 of apparently good data for a given station. The Predicted 186SL096130147 Tide Method for filling gaps consists of statistically 186SL096130148 comparing the predicted tides to the observed data and 186SL096130149 shifting the predicted tides in time to correct for timing 186SL096130150 differences. Then the linear interpolation between hourly 186SL096130151 values at the end points of the gap in the residual series is 186SL096130152 added to the corresponding corrected predicted tide data to 186SL096130153 obtain interpolated values over the span of the gap. 186SL096130154 186SL096130155 Bloomfield, P., 1976. Fourier Analysis of Time Series: An 186SL096130156 Introduction. New York: John Wiley and Sons. pp 129-137. 186SL096130157 186SL096130158 Foreman, M., 1977. Manual For Tidal Height Analysis and 186SL096130159 Prediction. Institute of Ocean Sciences, Patricia Bay, 186SL096130160 Victoria B.C. Pacific Marine Science Report 77-10. 186SL096130161 186SL09616 19751 2432000 2443000 2470000 2579000 2626000 2760000 186SL09616 19752 2781000 2928000 2910000 2823000 2686000 2460000 186SL09616 19761 2335000 2564000 2479000 2610000 2659000 2792000 186SL09616 19762 2857000 2783000 2854000 2711000 2497000 2423000 186SL09616 19771 2388000 2353000 2422000 2512000 2591000 2745000 186SL09616 19772 2796000 2858000 2843000 2716000 2514000 2539000 186SL09616 19781 2337000 2385000 2449000 2529000 2609000 2700000 186SL09616 19782 2806000 2825000 2775000 2684000 2515000 2415000 186SL09616 19791 2353000 2386000 2507000 2517000 2612000 2733000 186SL09616 19792 2816000 2798000 2775000 2684000 2462000 2463000 186SL09616 19801 2376000 2290000 2418000 2500000 2565000 2645000 186SL09616 19802 2749000 2834000 2716000 2625000 2548000 2355000 186SL09616 19811 2354000 2428000 2470000 2517000 2560000 2722000 186SL09616 19812 2755000 2833000 2813000 2632000 2542000 2372000 186SL09616 19821 2348000 2397000 2437000 2527000 2638000 2657000 186SL09616 19822 2757000 2832000 2758000 2707000 2506000 2338000 186SL09616 19831 2346000 2360000 2482000 2520000 2626000 2753000 186SL09616 19832 2787000 2819000 2847000 2676000 245201099999999 186SL09616 19841 2387000 2352000 2439000 2557000 2614000 2736000 186SL09616 19842 2785000 2831000 2737000 2681000 2632000 2447000 186SL09616 19851 2368000 2467000 2420000 2535000 2645000 2772000 186SL09616 19852 2792000 2869000 2756000 2700000 2544000 2390000 186SL09616 19861 2326000 2388000 2542000 2550000 2584000 2735000 186SL09616 19862 2813000 2841000 2783000 2647000 2523000 2538000 186SL09616 19871 2428000 2408000 2494000 2544000 2607000 2708000 186SL09616 19872 2797000 2821000 2768000 2723000 2595000 2471000 186SL09616 19881 2364000 2409000 2520000 2565000 2670000 2742000 186SL09616 19882 2883000 2820000 2781000 2686000 2438000 2380000 186SL09616 19891 2438000 2422000 2487000 2572000 2632000 2747000 186SL09616 19892 2809000 2927000 2839000 2624000 2551000 2532000 186SL09616 19901 2435000 2448000 2473000 2567000 2637000 2742000 186SL09616 19902 2775000 2880000 2871000 2716000 2620000 2365010