QUALITY ASSESSMENT OF SEA LEVEL DATA by the UH SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER JOINT ARCHIVE FOR SEA LEVEL Station : Ensenada, Baja Calif. Latitude: 31 51.0N Country : Mexico Longitude: 116 38.0W JASL # : 317A Time Meridian: 120W (GMT - 8 hr) GLOSS # : none TOGA #: none NODC #: 73111601 Contributor : Servicio Mareografico Nacional Instituto de Geofisica Universidad Nacional Autonoma de Mexico 04510 Mexico, D. F. MEXICO Originator : same Original Data: analog Instrmnt Type: standard gauge with float and stilling well Digitzd Intvl: hourly to tenths of feet Present Data : Hourly, daily, and monthly values obtained by: Hourly : spot sample on the hour from the analog roll 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 : 24 May 1956 - 02 May 1991 Gaps > 1 mon : 01 Jan 1959 - 20 Feb 1959;04 Jun 1961 - 01 Sep 1961 01 Jun 1969 - 01 Jul 1969;01 Jan 1976 - 02 Jan 1981 Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 Units : millimeters Missing Data Flag : 9999 Existing : Yes Operational : Yes Sat. Trans. : No Distribution : 1956-1991 Refernce Levl: The data are referred to tide staff zero which is linked to fixed bench marks. However, comparisons with neighboring sites and examination of the hourly residuals has lead to the following adjustment: period value added ( (hour)day/month/year ) to original(mm) --------------------------- --------------- (12)11/07/58 - (23)30/07/58 60 (18)13/06/63 - (19)21/06/64 100 (08)01/01/71 - (01)18/02/71 140 (16)29/04/82 - (10)05/07/82 -75 These adjustments are accurate to a few centimeters. Comment : The mean level within the difference of daily values with San Diego and sites to the south agree to within a few centimeters up until December, 1987. From this point onward, many level shifts are suspected: Date comment ----------- ------------------------- 29 Nov 1987 5 cm fall 13 Jan 1988 10 cm rise 01 Oct 1988 5 cm fall 02 Nov 1988 5 cm rise From May to Sep 1989, there is an upward trend totally a rise of 10 cm, after which the mean level remains fairly steady until the end of the series. Notable episodic events: 09-10 Mar 1957: Tsunami from C. Aleutians 23-25 May 1960: Tsunami from S.C. Chile 28 Mar 1964: Tsunami from Alaska CI MISSING REPLACED GAPS QUESTIONABLE YEAR (%) DATA OR BAD DATA FLUCTUATIONS ---- --- -------------------- --------------- -------------------- 1956 61 none (14)323-(00)324 none 1957 100 none (08)012-(07)013 324-325 (08)209-(07)210 (07)304-(16)304 1958 100 none (18)281-(04)282 181-182,193-217, 223-225,267 1959 89 1-41 (19)092-(06)093 56-58 (07)363-(15)363 1960 99 29-30 none none 1961 75 155-244 (17)015-(03)016 151-153 (02)034-(09)034 1962 100 none none none 1963 100 none (05)173-(22)173 none 1964 100 none none 352-353 1965 100 none none none 1966 100 none (08)027-(18)027 none (13)339-(21)339 (09)345-(16)345 1967 100 none (15)108-(23)108 364-365 1968 100 none (06)137-(21)137 none 1969 92 152-182 none none 1970 100 none (13)061-(01)062 331-333 (11)081-(01)082 (12)149-(19)149 1971 100 none none 1-3,349-355 1972 100 none (20)131-(11)132 290-297 (23)147-(06)148 1973 100 none none 235-248,266-268,297 1974 100 none (04)230-(12)230 none 1975 100 none (19)098-(02)099 none (18)164-(08)165 (21)217-(07)218 1976 0 1-366 none none 1977 0 1-365 none none 1978 0 1-365 none none 1979 0 1-365 none none 1980 0 1-366 none none 1981 99 1-2 (01)102-(11)102 184,343 (00)107-(07)107 1982 100 none (06)057-(17)057 6 1983 99 171-172 (03)053-(11)053 351-360 (18)061-(01)062 (12)330-(23)330 1984 100 none (08)025-(07)026 46-49,75-76,101-111, (17)033-(07)034 120,162-164,188,209, (08)066-(07)067 211,215,273,299-302, (08)083-(07)084 326,343-344,354-355 (13)097-(05)098 (08)239-(07)240 (16)366-(07)001 1985 100 none (08)044-(07)045 53,69,73,83,85-86, (08)151-(07)152 96-97,107,109-112, (16)152-(01)153 124-125 (08)186-(07)187 (08)258-(07)259 1986 100 1 (10)083-(09)084 316,332,335-337, (23)144-(20)145 352-353,362 1987 100 none (07)057-(22)057 111-114 (15)307-(07)308 (17)340-(05)341 (19)341-(07)342 (22)346-(08)347 1988 99 136-138 (08)103-(07)104 113,158,255,260-261 (14)327-(03)328 1989 100 none (17)258-(16)259 69,364 1990 100 none (23)034-(20)035 172,315-317 1991 33 none none 32