QUALITY ASSESSMENT OF SEA LEVEL DATA by the UH SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER JOINT ARCHIVE FOR SEA LEVEL updated: 01 Oct 2020 Station : Boston,MA Latitude: 42 21.3N Country : USA Longitude: 071 03.1W JASL # : 741A Time Meridian: 075W (GMT - 5 hr) GLOSS # : none Originator #:8443970 NODC #: 74072101 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 Originator : US Coastal Geodetic Survey (1921-1972);NOS (1973+) Original Data: unconfirmed; 1993+ digital Instrmnt Type: float/well system (1921-1992); Aquatrak acoustic gauge, NOAA Next Generation Water Level Measuring System (NGWLMS) (1993-); Design Analysis WaterLOG Microwave sensor (MWWL) radar gauge (2017-) Digitzd Intvl: unconfirmed; 1993+ six-minute NGWLMS,MWWL 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 : 03 May 1921 - 31 Dec 2019 Gaps > 1 mon : 01 Jun 1921 - 24 Jul 1921;13 Jan 1945 - 07 May 1945 Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 Units : millimeters Missing Data Flag : 9999 Existing : Yes Operational : Yes Sat. Trans. : Yes Distribution : 1921-2019 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. Comment : The daily and monthly means reveal no apparent reference level changes or trends and agree with the nearest stations. Timing accuracy was no better than about +/- 7 minutes prior to 1979. Only extreme deviations are noted below. CI MISSING REPLACED GAPS QUESTIONABLE YEAR (%) DATA OR BAD DATA FLUCTUATIONS ---- --- -------------------- --------------- -------------------- 1921 52 152-205 none 306,308 1922 100 none none 10-12,187-198 1923 100 none none 262 1924 100 none none 93,239 1925 100 none none none 1926 100 none none none 1927 100 none none 35-36 1928 100 none none none 1929 100 none none none 1930 100 none none none 1931 100 none none none 1932 100 none none 36 1933 100 none none none 1934 100 none none none 1935 100 none none 31-32,242,322 1936 100 none none none 1937 100 none none none 1938 100 none none 215-216,264 1939 100 none none none 1940 100 none none none 1941 100 none none none 1942 100 none none none 1943 100 none none none 1944 100 none none 49,132,259 1945 68 7-9,13-127 none 274-277 1946 100 none none 57-58 1947 100 none none none 1948 100 none none none 1949 100 none none 29-36,41-44 1950 100 none none none 1951 100 none none 90-93,166-177 1952 100 none none none 1953 100 none none 239-242 1954 100 none none 93,167-174,243, 254,341-343 1955 100 none none 202-203 1956 100 none none none 1957 100 none none none 1958 100 none none none 1959 100 none none none 1960 100 none (19)101-(03)102 none 1961 98 249-258 none 103-104 1962 99 229-233 none 7-8 1963 100 none none 127-128,323-326 1964 100 none none 47-48,322 1965 100 none none none 1966 100 none none 62-69,172-174 1967 100 none none none 1968 98 343-350 none 331-333 1969 98 245-254 none 105 1970 100 none none 43-44,74-75 1971 94 282-305 none 30-31,225-227,281 1972 100 none none none 1973 100 none none none 1974 90 283-292,297-325 none 292-297 1975 100 none none none 1976 98 64-70 none none 1977 99 344-346 none 74 1978 100 none none 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 154,270 1986 100 none none 1-6 1987 100 none none 227-229 1988 100 none none 254-255 1989 100 none none none 1990 98 82-86,186-188 (19)172-(17)173 170-172 (18)191-(06)192 1991 100 none (14)204-(21)204 146-149,169-175 (19)207-(02)208 (07)208-(14)208 (07)209-(14)209 1992 100 none (18)001-(17)002 none (08)337-(17)337 1993 97 99-103,107-109,112- (10)034-(17)034 none 113,121-124 1994 99 68-69,311-312 (21)032-(17)033 none (00)067-(11)067 1995 99 242-243 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 (14)018-(12)019 none 2001 99 30-31 (02)290-(21)290 none 2002 100 none none none 2003 99 57-59 (16)047-(15)048 none (19)048-(03)049 (20)049-(04)050 2004 94 11-12,14-18,19-35 none none 2005 100 none none none 2006 100 none none none 2007 99 204-205 (06)206-(13)206 none (04)207-(22)207 (04)208-(17)208 2008 100 none none none 2009 97 236-246 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 98 186-193 none none 2018 100 none none none 2019 100 none none none