QUALITY ASSESSMENT OF SEA LEVEL DATA by the UH SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER JOINT ARCHIVE FOR SEA LEVEL updated: 09 Sep 2020 Station : Sitka,AK Latitude: 57 03.1N Country : USA Longitude: 135 20.5W JASL # : 559A Time Meridian: 120W (GMT - 8 hr) GLOSS # : 154 Originator #:9451600 NODC #: 75137501 Contributor : National Ocean Service (NOS) National Ocean. and Atmos. Administration (NOAA) N/OES22 SSMC4, STATION 7109 1305 East West Highway Silver Spring, MD. 20910-3233 *1950-1974 were key-punched by funding from Dr. Doug Luther while he was at Scripps and were contributed to the JASL in 1995 *1938-1949, 1974-1979 were processed and provided by Dr. David Jay of Portland State University Originator : US Coastal Geodetic Survey (1938-1972);NOS (1973+) Original Data: analog (standard); digital (ADR and NGWLMS) Instrmnt Type: 1) standard mechanical, float/wire (1938-1967); 2) analog-to-digital (ADR) recorder, float/wire (1967-1994); 3) Aquatrak acoustic sensor/protective well, NOAA Next Generation Water Level Measuring System (NGWLMS) (1991-) Digitzd Intvl: hourly (standard); six-minute (adr and NGWLMS) NGWLMS sampling is three-minute average Present Data : Hourly, daily, and monthly values obtained by: Hourly : The original digitizing interval was hourly (standard); spot sampling on the hour (adr/NGWLMS) 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 : 20 May 1938 - 31 Dec 2019 Gaps > 1 mon : 01 Jul 1966 - 01 Aug 1966;02 Apr 1973 - 07 Aug 1973 15 Sep 1976 - 25 Oct 1976 Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 Units : millimeters Missing Data Flag : 9999 Existing : Yes Operational : Yes Sat. Trans. : Yes Distribution : 1938-2019 Refernce Levl: All heights have been referred to the station tide staff zero which is linked to fixed bench marks. While standard mechanical or ADR instrument was the primary gauge, leveling calibration factors were applied monthly based on tide staff comparisons. Level adjustments were based on comparisons with neighboring stations and the holdings of the Permanent Service for Mean Sea Level (PSMSL): added to YYYY MM DD HH YYYY MM DD HH original (mm) 1953/01/01/00Z-1953/12/31/23Z -20 1954/01/01/00Z-1954/12/31/23Z 20 The mean level agrees with the PSMSL series although noise of +/- 1cm exists throughout. This series may be replaced when the final NOAA/NOS series becomes available for the hourly data. Comment : The daily and monthly means reveal no apparent reference level changes or trends and agree with the nearest stations. This site is referred to as "Sitka, Baronof Island, Sitka Sound, AK" by the originators. An apparent stilling well blockage occurred from late August through September 1992. Notable episodic events: 04-06 Nov 1952: Tsunami from Kamchatka 09-10 Mar 1957: Tsunami from C. Aleutians 23-25 May 1960: Tsunami from S.C. Chile 28-29 Mar 1964: Tsunami from Alaska 11-12 Mar 2011: Tsunami from Japan CI MISSING REPLACED GAPS QUESTIONABLE YEAR (%) DATA OR BAD DATA FLUCTUATIONS ---- --- -------------------- --------------- -------------------- 1938 62 none none 208 1939 100 none none 252-255,271-272 1940 100 none none none 1941 100 none (00)001-(07)001 160 1942 100 none none 1,46-47 1943 100 none none none 1944 100 none none none 1945 97 105-106,119-127 (08)093-(16)093 none (14)098-(21)098 (06)102-(14)102 (12)108-(20)108 (02)109-(22)109 (03)110-(20)110 (01)111-(21)111 (15)112-(22)112 (03)113-(00)114 (05)114-(19)114 (04)115-(13)115 (05)117-(13)117 (05)130-(20)130 (05)131-(12)131 (05)132-(14)132 (06)133-(13)133 1946 100 none none none 1947 100 none none none 1948 100 none none none 1949 100 none (00)001-(07)001 none 1950 100 none (08)334-(23)334 none (08)355-(07)356 1951 100 none (08)200-(07)201 none 1952 100 none none none 1953 100 none none none 1954 100 none none none 1955 100 none none none 1956 100 none none none 1957 100 none none none 1958 100 none none 236-238 1959 100 none none none 1960 100 none none 242,245-250 1961 100 none none none 1962 100 none none none 1963 100 none none 274 1964 100 none (08)314-(07)315 none 1965 100 none (19)303-(07)304 none 1966 91 182-213 none 361-366 1967 100 none none 1-5,152-156 1968 100 none none none 1969 100 none none none 1970 100 none none none 1971 100 none none none 1972 100 none none none 1973 65 92-219 none 21-22,35-38,49-53, 62-92,268,328-329, 342-349 1974 98 60-68 none none 1975 100 none (14)076-(00)077 none 1976 89 259-299 none 241-244,307-308 1977 100 none none none 1978 100 none (00)001-(07)001 none 1979 100 none none none 1980 100 none none none 1981 100 none none none 1982 100 none none none 1983 100 none none none 1984 100 none none none 1985 100 none none none 1986 100 none none none 1987 100 none none none 1988 100 none none none 1989 100 none none none 1990 100 none none none 1991 99 35-37 (18)084-(17)085 none 1992 100 none (15)366-(23)366 238-273 1993 100 none none none 1994 100 none (13)168-(20)168 none 1995 100 none none none 1996 100 none none none 1997 100 none none none 1998 100 none none none 1999 100 none none none 2000 100 none none none 2001 100 none none none 2002 100 none none none 2003 100 none none none 2004 100 none none none 2005 100 none none none 2006 100 none (12)249-(23)249 none 2007 100 none (11)119-(22)119 none (00)127-(16)127 2008 100 none none none 2009 100 none none none 2010 100 none none none 2011 100 none none none 2012 100 none none none 2013 100 none none none 2014 100 none none none 2015 100 none none none 2016 100 none none none 2017 100 none none none 2018 100 none none none 2019 100 none none none