186SL0681150172101 013A 19490528 19670915 0249S 17143W 2 00000R 0000 MM 186SL0681250172101 Kanton-A Rep. of Kiribati Scripps Inst. Ocean. 186SL068130001 186SL068130002 QUALITY ASSESSMENT OF SEA LEVEL DATA 186SL068130003 by the 186SL068130004 TOGA SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER 186SL068130005 JOINT ARCHIVE FOR SEA LEVEL 186SL068130006 186SL068130007Station : Kanton-A Latitude: 02 48.6S 186SL068130008Country : Republic of Kiribati Longitude: 171 43.1W 186SL068130009JASL # : 013A Time Meridian: 165W (GMT -11 hr) 186SL068130010GLOSS # : 145 TOGA #: P052 NODC #: 50172101 186SL068130011Contributor : Scripps Institute of Oceanography 186SL068130012 University of California at San Diego 186SL068130013 La Jolla, California 186SL068130014Originator : unconfirmed 186SL068130015Original Data: unconfirmed 186SL068130016Instrmnt Type: unconfirmed 186SL068130017Digitzd Intvl: unconfirmed 186SL068130018Present Data : Hourly, daily, and monthly values obtained by: 186SL068130019 Hourly : unconfirmed 186SL068130020 Daily : 119-point convolution filter (Bloomfield, 1976) 186SL068130021 centered on noon applied to the hourly data 186SL068130022 with respective periods of the 95, 50, and 5% 186SL068130023 amplitude points at 124.0, 60.2, and 40.2 hours 186SL068130024 Monthly: Simple average of all daily values; calculated if 186SL068130025 7 or fewer days are missing 186SL068130026Span of data : 28 May 1949 - 15 Sep 1967 186SL068130027Gaps > 1 mon : none 186SL068130028Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 186SL068130029Units : millimeters Missing Data Flag :99999 186SL068130030Refernce Levl: All heights have been referred to the station tide 186SL068130031 staff zero which is linked to fixed bench marks 186SL068130032Comment : The daily and monthly means reveal no apparent 186SL068130033 changes in the reference level and agree well 186SL068130034 with Christmas Island. The timing is not better 186SL068130035 than +/- 7 minutes. 186SL068130036 186SL068130037 CI MISSING REPLACED GAPS QUESTIONABLE 186SL068130038YEAR (%) DATA OR BAD DATA FLUCTUATIONS 186SL068130039---- --- -------------------- --------------- -------------------- 186SL0681300401949 60 none none none 186SL0681300411950 100 none none none 186SL0681300421951 100 none none none 186SL0681300431952 100 none none none 186SL0681300441953 100 none none none 186SL0681300451954 100 none none none 186SL0681300461955 100 none (17)124-(02)125 none 186SL0681300471956 100 none none none 186SL0681300481957 98 98-106 none none 186SL0681300491958 100 none none none 186SL0681300501959 100 none none none 186SL0681300511960 100 none (15)044-(08)045 none 186SL0681300521961 94 152-173 none none 186SL0681300531962 100 none none none 186SL0681300541963 100 none (10)058-(09)059 none 186SL0681300551964 100 none none none 186SL0681300561965 100 none (21)258-(08)259 none 186SL0681300571966 100 none (13)213-(21)213 none 186SL0681300581967 71 none none none 186SL068130059 186SL068130060 QUALITY ASSESSMENT POLICY 186SL068130061 186SL068130062 The quality assessment is mostly based on the residuals 186SL068130063 (observed data minus predicted tides) of the hourly data. This 186SL068130064 assessment also applies to the daily and monthly data since 186SL068130065 they were derived from the quality-controlled hourly data. 186SL068130066 186SL068130067 The following abbreviations are used in the assessment: 186SL068130068 JASL - Joint Archive for Sea Level; GLOSS - Global Sea Level 186SL068130069 Observing System; TOGA - Tropical Ocean Global Atmosphere 186SL068130070 research program; NODC - National Oceanographic Data Center; 186SL068130071 Instrmnt - instrument; Digitzd Intvl - digitized interval; 186SL068130072 Gaps > 1 mon - missing data in a span greater than one month; 186SL068130073 Refernce - reference. 186SL068130074 186SL068130075 The following corrections are made to the hourly data 186SL068130076 prior to this assessment: 186SL068130077 1) Gaps or obviously wrong data points in a span less than 186SL068130078 25 hours are filled by the predicted tide method*. 186SL068130079 2) Timing errors of exact increments of an hour are corrected 186SL068130080 by shifting the data. 186SL068130081 3) Reference level shifts are only corrected after information 186SL068130082 from tide staff readings or comparative readings with a fixed 186SL068130083 bench mark are checked to verify that the shift was not a 186SL068130084 natural event. If comparative readings are missing or 186SL068130085 incomplete, comparisons of the data with nearby stations 186SL068130086 may warrant the adjustment of some obvious shifts. 186SL068130087 4) Data with unresolved datum shifts are not disseminated. 186SL068130088 However, if sufficient time spans of data are available before 186SL068130089 or after the year(s) with the unresolved shift(s), a subset of 186SL068130090 quality assured data is made available. Thus, the Span field 186SL068130091 in the Quality Assessment may not match the span of the 186SL068130092 distribution data set. As the questionable datum shifts are 186SL068130093 resolved, the data set will be updated. Although this policy 186SL068130094 adds some complexity, it allows more rapid dissemination of 186SL068130095 at least the quality assured years. 186SL068130096 186SL068130097 For each year, the following information is documented from 186SL068130098 the quality-controlled hourly data with dates given as the nth 186SL068130099 day of the year starting from 1 January: 186SL068130100 1) a Completeness Index (CI) based on the percentage of hours 186SL068130101 with available data, 186SL068130102 2) a list of gaps longer than a day, 186SL068130103 3) a summary of days with consecutive missing or obviously 186SL068130104 wrong data in a time span longer than 6 but less than 25 186SL068130105 hours that have been replaced, with hours in parentheses, and 186SL068130106 4) a summary of days with questionable fluctuations in the 186SL068130107 residual series. Fluctuations within the residuals are 186SL068130108 considered significant and are noted if they are greater than 186SL068130109 25 cm. This policy has changed slightly as of October 1992: 186SL068130110 only suspicious fluctuations due to obvious instrumentation 186SL068130111 problems are noted. Minor timing drifts are no longer 186SL068130112 included in the list of questionable days. 186SL068130113 186SL068130114 Note : If the predicted tides poorly model the observed heights 186SL068130115 due to the inability of the tidal analysis to completely resolv 186SL068130116 the non-linear shallow water effects, the residuals are not 186SL068130117 suitable for assessing the data quality. Instead, a subjective 186SL068130118 comment on the quality of the data is provided. 186SL068130119 186SL068130120 *The predicted tides are obtained with the use of a harmonic 186SL068130121 analysis program (Foreman, 1977) which is executed on a year 186SL068130122 of apparently good data for a given station. The Predicted 186SL068130123 Tide Method for filling gaps consists of statistically 186SL068130124 comparing the predicted tides to the observed data and 186SL068130125 shifting the predicted tides in time to correct for timing 186SL068130126 differences. Then the linear interpolation between hourly 186SL068130127 values at the end points of the gap in the residual series is 186SL068130128 added to the corresponding corrected predicted tide data to 186SL068130129 obtain interpolated values over the span of the gap. 186SL068130130 186SL068130131 Bloomfield, P., 1976. Fourier Analysis of Time Series: An 186SL068130132 Introduction. New York: John Wiley and Sons. pp 129-137. 186SL068130133 186SL068130134 Foreman, M., 1977. Manual For Tidal Height Analysis and 186SL068130135 Prediction. Institute of Ocean Sciences, Patricia Bay, 186SL068130136 Victoria B.C. Pacific Marine Science Report 77-10. 186SL068130137 186SL06816 19491 9999999999999999999999999999999999999999 1351000 186SL06816 19492 1365000 1374000 1385000 1393000 1391000 1405000 186SL06816 19501 1381000 1369000 1366000 1348000 1335000 1348000 186SL06816 19502 1398000 1403000 1364000 1400000 1415000 1463000 186SL06816 19511 1459000 1400000 1442000 1422000 1400000 1377000 186SL06816 19512 1399000 1416000 1436000 1448000 1451000 1483000 186SL06816 19521 1481000 1433000 1408000 1378000 1369000 1390000 186SL06816 19522 1425000 1430000 1457000 1455000 1472000 1484000 186SL06816 19531 1484000 1403000 1403000 1381000 1397000 1379000 186SL06816 19532 1415000 1448000 1468000 1453000 1429000 1484000 186SL06816 19541 1433000 1397000 1447000 1437000 1420000 1414000 186SL06816 19542 1423000 1441000 1433000 1422000 1473000 1455000 186SL06816 19551 1490000 1390000 1398000 1429000 1391000 1388000 186SL06816 19552 1387000 1388000 1409000 1390000 1425000 1439000 186SL06816 19561 1459000 1407000 1412000 1415000 1350000 1378000 186SL06816 19562 1447000 1435000 1438000 1452000 1465000 1506000 186SL06816 19571 1482000 1477000 145700099999999 1405000 1359000 186SL06816 19572 1423000 1460000 1508000 1516000 1596000 1467000 186SL06816 19581 1511000 1483000 1459000 1442000 1420000 1404000 186SL06816 19582 1445000 1454000 1464000 1475000 1508000 1574000 186SL06816 19591 1530000 1556000 1490000 1427000 1421000 1391000 186SL06816 19592 1422000 1467000 1469000 1477000 1480000 1454000 186SL06816 19601 1482000 1416000 1414000 1408000 1392000 1395000 186SL06816 19602 1432000 1413000 1458000 1482000 1464000 1496000 186SL06816 19611 1465000 1435000 1460000 1430000 137900099999999 186SL06816 19612 1438000 1460000 1482000 1481000 1443000 1468000 186SL06816 19621 1381000 1394000 1384000 1373000 1400000 1387000 186SL06816 19622 1397000 1442000 1450000 1455000 1477000 1478000 186SL06816 19631 1436000 1439000 1443000 1456000 1451000 1420000 186SL06816 19632 1471000 1502000 1554000 1553000 1535000 1523000 186SL06816 19641 1513000 1444000 1351000 1388000 1398000 1385000 186SL06816 19642 1407000 1420000 1414000 1407000 1445000 1511000 186SL06816 19651 1496000 1524000 1458000 1455000 1420000 1415000 186SL06816 19652 1486000 1534000 1565000 1597000 1568000 1526000 186SL06816 19661 1511000 1464000 1419000 1456000 1408000 1378000 186SL06816 19662 1415000 1414000 1433000 1460000 1450000 1427000 186SL06816 19671 1414000 1416000 1422000 1428000 1422000 1417000 186SL06816 19672 1438000 145300099999999999999999999999999999999