QUALITY ASSESSMENT OF SEA LEVEL DATA by the UH SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER JOINT ARCHIVE FOR SEA LEVEL updated: 11 Jan 2018 Station : Colombo-C Latitude: 06 56.1N Country : Sri Lanka Longitude: 079 51.5E JASL # : 115C Time Meridian: 82.5E (GMT + 5.5) GLOSS # : 033 Originator #: 115 NODC #: 10076901 Contributor : UH Sea Level Center 1000 Pope Rd. MSB 317 Honolulu, Hawaii 96822 Originator : UH Sea Level Center in collaboration with National Aquatic Resources Agency Crow Island, Mattakkuliya Colombo-15 SRI LANKA Original Data: digital Instrmnt Type: 1. 2006- Handar 436-A, Encoder (ENC); 2. 2006- Handar 436-B (ENB) with datalogger (ENO) 3. 5/2006- pressure transducer (PRS) 4. 5/2006- radar (RAD) (Vega Vegapuls 62) Primary channel used in JASL set: 2006-02/Jul/2007: RAD 03/Jul/2007-20/Jul/2007: ENC 21/Jul/2007-23/Oct/2008: RAD 24/Oct/2008-23/Jul/2009: END 24/Jul/2009-26/Aug/2009: RAD 27/Aug/2009-02/Sep/2009: ENC 03/Sep/2009-04/May/2012: RAD 05/May/2012-30/Jul/2012: ENC 31/Jul/2012-25/Oct/2016: RAD *short gaps in primary channel filled with other channels as available; see UHSLC for specific dates Digitzd Intvl: 4 min (ENC), 15 min (ENB,ENO); 2 min (PRS), 3 min (RAD) Present Data : Hourly, daily, and monthly values obtained by: Hourly : A three-point Hanning filter centered on the hour Daily : 119-point convolution filter (Bloomfield, 1976) centered on noon applied to the hourly data with respective periods of the 95, 50, and 5% amplitude points at 124.0, 60.2, and 40.2 hours Monthly: Simple average of all daily values; calculated if 7 or fewer days are missing Span of data : 06 May 2006 - 25 Oct 2016 Gaps > 1 mon : none Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 Units : millimeters Missing Data Flag : 9999 Existing : Yes Operational : Yes Sat. Trans. : No Distribution : 2006-2016 Refernce Levl: Heights are referred to the station tide staff zero, which is linked to land-based benchmarks. This reference zero is unique to this station and is not an official datum (chart, national, etc.) and is not relative to local tidal parameters, such as mean lower low water. See the Originators for benchmark descriptions, maps, and the geodetic levelling history. Comment : The daily and monthly values do not reveal any obvious reference level shifts or trends. This series is separate from 115A and 115B because they are not linked to the same datum. Difference with AVISO altimeter suggests there could be station sinking at Colombo-C. It is under investigation. Use long-term trend with discretion. This station was terminated in Oct 2016 and moved to a new location, which has not been geodetically linked. Thus data from 04 Jan 2017 begin a new independent series, 115D CI MISSING REPLACED GAPS QUESTIONABLE YEAR (%) DATA OR BAD DATA FLUCTUATIONS ---- --- -------------------- --------------- -------------------- 2006 65 none none none 2007 100 none none none 2008 100 none none none 2009 100 none (08)123-(21)123 none (08)360-(23)360 2010 99 38-41 (04)037-(18)037 none (02)038-(12)038 (21)041-(17)042 (23)042-(17)043 (22)043-(18)044 (21)044-(17)045 (22)045-(06)046 2011 100 none (11)181-(18)181 none 2012 99 262-264 none none 2013 100 none (13)174-(23)174 none 2014 100 none none none 2015 100 none none none 2016 67 299-366 none none