Mera (Japan) Site History

History Summary

Station name Mera
Country Japan
Latitude 34° 55.0' N
Longitude 139° 50.0' E
GLOSS No. 086
Contributor 1965-1986 TOGA Sea Level Center
1987-2009 Japan Meteorological Agency
Instrument Type FUESS (1965-1972)
LFT-4 (1973-1999)
Fuess float operated gauge (2001-2005)
Acoustic gauge (2006-2009)
Site of Gauge  
Observational Periods 1965 - present

Benchmarks

Reference Level

All heights have been referred to the station Tide Gauge Zero (TGZ) which is linked to fixed bench marks.

Tide Gauge Benchmark (TGBM) Description

Japan Meteorlogical Agency Benchmark bolt inside tide gauge hut, adjacent to stilling well

Auxiliary Benchmarks

Tide station Benchmark 4.3031m above Tokyo Peil (1984).

Benchmark Relationships

Year Standard Mark (TGBM)
above Datum Line (TGZ)
Standard Mark (TGBM)
above Tokyo Peil (TP)
TGZ below TP
1968-2000 6.671 5.401 -1.270
2001 6.671 5.323 -1.348
2002 6.671 5.352 -1.319
2003-2008 6.671 5.297 -1.374
2009 6.671 5.287 -1.384

Parameter Code

ASLVZZ01 - The elevation of the sea surface to a known datum, measured in metres.

Quality Assessment

The daily or monthly means do not reveal any obvious reference level shifts. Prior to 2001 most questionable fluctuations are related to timing problems with the gauge. Data spikes of about 10cm or less have not been corrected. In some years gaps in data have been replaced, details can be found in Replaced gaps table below.

Completeness index (CI)

Sea level data from Japan is processed for each year. Occasionally data is missing from the data sets, either because the data set does not cover the whole year or because data has been flagged null. The number of cycles in a year with no missing data is calculated (based on the sample interval and whether a leap year). The completeness index calculates what proportion of the data expected in a year is present and not flagged null.

Quality index (QI)

During processing cycles considered suspect within a series are flagged M. The quality index calculates what proportion of the data available is not considered suspect.

Yearly overview of data

Year CI (%) QI (%) Start and end date (UTC) Sampling interval
(minutes)
Missing Data
(cycle no.)
Suspect Data
(cycle no.)
Parameter Code
1965 99.9 97.4 1965-01-01 00:00 to 1965-12-31 14:00 60 None 1120, 1127, 1302, 2224, 3649, 4080, 4263, 4780, 5182, 6222-6435, 7588, 8190 ASLVZZ01
1967 0.1 100.0 1967-12-31 15:00 to 1967-12-31 23:00 60 None None ASLVZZ01
1968 99.1 99.7 1968-01-01 00:00 to 1968-12-31 23:00 60 3090-3145, 3487-3511 465, 533, 607, 609, 783, 821, 873-874, 951, 1897, 2542, 2712-2713, 3240, 3630, 4090, 4198, 4294, 4352, 5576, 5672, 7207, 8403, 8620 ASLVZZ01
1969 100.0 99.8 1969-01-01 00:00 to 1969-12-31 23:00 60 None 2898, 3856, 8418, 8455, 8485, 8505-8506, 8594, 8701, 8754 ASLVZZ01
1970 100.0 99.8 1970-01-01 00:00 to 1970-12-31 23:00 60 None 1475, 3602, 4352, 4454 ASLVZZ01
1971 100.0 99.8 1971-01-01 00:00 to 1971-12-31 23:00 60 None 254, 897, 1473, 2673, 6178, 6187, 6586, 6958, 7476, 7479, 7606, 7683, 7767, 8206, 8394 ASLVZZ01
1972 100.0 99.8 1972-01-01 00:00 to 1972-12-31 23:00 60 None 380, 846, 1591, 1670, 1852-1853, 1859, 1867, 1888, 3011, 3044, 3970, 4745, 4783, 6932, 7126, 7623, 7897, 8000, 8136, 8383 ASLVZZ01
1973 100.0 99.6 1973-01-01 00:00 to 1973-12-31 23:00 60 None 87, 110, 161, 180, 461, 512, 549, 1249, 1809, 1850, 2368, 2462, 2522, 3198, 3359, 3441, 3508, 3621, 4194, 4426, 4489, 4514-4516, 4556, 4645, 4915, 6202, 7068, 7263, 7438, 7650, 7664, 7985, 8458, 8530 8623, 8634 ASLVZZ01
1974 100.0 98.7 1974-01-01 00:00 to 1974-12-31 23:00 60 None 709, 973, 1370, 1376, 1446, 1479, 1521, 2382, 2769-2770, 2893, 2980, 3044, 3354, 3453, 3855, 3958, 4062, 5975, 6177-6268 ASLVZZ01
1975 57.5 99.6 1975-01-01 00:00 to 1975-12-31 23:00 60 1248-1299, 1408-5079 623, 1048, 8677 ASLVZZ01
1976 100.0 99.8 1976-01-01 00:00 to 1976-12-31 23:00 60 None 998, 4563, 4964 ASLVZZ01
1977 100.0 99.8 1977-01-01 00:00 to 1977-12-31 23:00 60 None 2978 ASLVZZ01
1978 100.0 99.8 1978-01-01 00:00 to 1978-12-31 23:00 60 None 2552, 4410 ASLVZZ01
1979 100.0 99.8 1979-01-01 00:00 to 1979-12-31 23:00 60 None 3891 ASLVZZ01
1980 99.6 99.8 1980-01-01 00:00 to 1980-12-31 23:00 60 788-819 1184, 3249, 5714, 6876 ASLVZZ01
1981 100.0 99.8 1981-01-01 00:00 to 1981-12-31 23:00 60 None 1543 ASLVZZ01
1982 100.0 99.8 1982-01-01 00:00 to 1982-12-31 23:00 60 None 6081 ASLVZZ01
1983 100.0 100.0 1983-01-01 00:00 to 1983-12-31 23:00 60 None None ASLVZZ01
1984 100.0 100.0 1984-01-01 00:00 to 1984-12-31 23:00 60 None None ASLVZZ01
1985 100.0 100.0 1985-01-01 00:00 to 1985-12-31 23:00 60 None None ASLVZZ01
1986 99.9 100.0 1986-01-01 00:00 to 1986-12-31 14:00 60 None None ASLVZZ01
1987 98.2 100.0 1986-12-31 15:00 to 1987-12-31 14:00 60 2427-2508, 3923-3997, 7885-7889 None ASLVZZ01
1988 99.9 100.0 1987-12-31 15:00 to 1988-12-31 14:00 60 1969-1981 None ASLVZZ01
1989 99.9 99.9 1988-12-31 15:00 to 1989-12-31 14:00 60 3315-3321 6294 ASLVZZ01
1990 100.0 100.0 1989-12-31 15:00 to 1990-12-31 14:00 60 None None ASLVZZ01
1991 100.0 100.0 1990-12-31 15:00 to 1991-12-31 14:00 60 None None ASLVZZ01
1992 100.0 100.0 1991-12-31 15:00 to 1992-12-31 14:00 60 None None ASLVZZ01
1993 99.9 100.0 1992-12-31 15:00 to 1993-12-31 14:00 60 7636-7642, 7736-7739 None ASLVZZ01
1994 99.9 100.0 1993-12-31 15:00 to 1994-12-31 14:00 60 2583-2586 None ASLVZZ01
1995 100.0 100.0 1994-12-31 15:00 to 1995-12-31 14:00 60 None None ASLVZZ01
1996 100.0 99.6 1995-12-31 15:00 to 1996-12-31 14:00 60 None 365-366, 6366-6396 ASLVZZ01
1997 100.0 99.6 1996-12-31 15:00 to 1997-12-31 14:00 60 None 4090-4110, 4289-4306 ASLVZZ01
1998 100.0 99.8 1998-01-01 00:00 to 1998-12-31 23:00 60 None 6184-6198 ASLVZZ01
1999 100.0 100.0 1999-01-01 00:00 to 1999-12-31 23:00 60 None 6184-6198 ASLVZZ01
2001 100.0 100.0 2000-12-31 15:00 to 2001-12-31 14:00 60 None None ASLVZZ01
2002 100.0 99.7 2001-12-31 15:00 to 2002-12-31 14:00 60 None 4582-4590, 6567-6583 ASLVZZ01
2003 99.8 100.0 2002-12-31 15:00 to 2003-12-31 14:00 60 2013-2026 None ASLVZZ01
2004 100.0 100.0 2003-12-31 15:00 to 2004-12-31 14:00 60 None None ASLVZZ01
2005 99.9 100.0 2004-12-31 15:00 to 2005-12-31 14:00 60 1790-1793 None ASLVZZ01
2006 100.0 100.0 2005-12-31 15:00 to 2006-12-31 14:00 60 None None ASLVZZ01
2007 99.9 100.0 2006-12-31 15:00 to 2007-12-31 14:00 60 7096-7097 None ASLVZZ01
2008 100.0 100.0 2007-12-31 15:00 to 2008-12-31 14:00 60 None None ASLVZZ01
2009 100.0 100.0 2008-12-31 15:00 to 2009-12-31 14:00 60 None None ASLVZZ01

Replaced gaps

Year Replaced Gaps (UTC)
1968 1968-05-23 06:00 to 1968-05-23 21:00,
1968-05-24 01:00 to 1968-05-25 00:00,
1968-05-26 12:00 to 1968-05-27 01:00 and
1968-05-27 23:00 to 1968-05-28 07:00
1974 1974-06-15 09:00 to 1974-06-15 17:00
1983 1983-01-07 07:00 to 1983-01-08 00:00 and
1983-01-08 03:00 to 1983-01-08 12:00
1986 1986-02-18 13:00 to 1986-02-19 04:00
1998 1998-09-14 10:00 to 1998-09-15 01:00