Mombasa (Kenya) Site History

History Summary

Station Mombasa
Country Kenya
Latitude 04° 04.2' S
Longitude 039° 39.4' E
GLOSS No 008
Time Reference GMT (hours 00-23)
Contributor UH Sea Level Center in collaboration with Kenya Marine and Fisheries Institute
Instrument Type Leupold and Stevens, model A-71, float gauge
Site of Gauge The gauge is situated between Telegraph Point and the yacht club at Ras Liwotoni.
Observational periods 1986 - present

Reference Level

All heights have been referred to the station tide gauge zero which is linked to fixed benchmarks.

Tide gauge benchmark (TGBM) description

Benchmark Elevation Description
BM@ 3.8m This is a bolt fixed on the tide staff.
BM1 5.683m TGZ is below BM1 - June 1989.
BM2 5.850m TGZ is below BM2 - June 1989.
BM3 13.883m TGZ is below BM3 - April 1987.
BM N-3 6.226m TGZ is below TGZ - June 1989.

Datum Levels

Tide gauge zero (TGZ) 0.942 m (Admiralty Chart Datum)
TGZ 0.912 m (East African Railways Datum)
TGZ 2.790 m (from 1989) (Survey of Kenya Datum)
TGZ 3.800m below BM@

Quality Assessment by the UH Sea Level Center

Comment

The daily and monthly means do not reveal any reference level shifts and agree well with an adjacent station, Zanzibar, except for about a 10 day period of 9-20 February 1990 when the daily values show a suspicious drop. Another suspicious rise occurs on 14-17 June 1990. These features are not identifiable in the tide staff observations.

The timing of the hourly data is uncertain to about 4 minutes for most of the record with periods of less accuracy as noted below under questionable fluctuations. The timing is more accurate beginning in 1992.

Year CI (%) Missing Data Replaced Gaps or Bad Data Questionable Fluctuations
1986 51 254-258,304-308,333-335,355-357 (13)216-(00)217 (15)217-(23)217 (19)219-(06)220 (23)222-(08)223 (02)320-(19)320 (01)324-(19)324 175,214-215,231-233,260-264,282,317-319,358-360
1987 78 37-40,130-132,147-159,215-222,310-365 (13)048-(21)048 (17)050-(03)051 (20)052-(05)053 (12)136-(22)136 (00)137-(10)137 (18)160-(05)161 (14)161-(23)161 (04)171-(23)171 59-60,67,73-74,80-84,88-89,91,93,106,134,142-147,168-169,173,177-178,194-195,214,222,224,227-228,275-278,281
1988 93 1-59,94-96,151-154,232-243,245-252,332-335 none 79-81,83-84,93-94,100-103,108-110,129-130,139-142,150-151,245,268-270,319,337,344-345
1989 98 104-107,122-124,242-244 none 6-7,27,39,66-67,69,78-79,87,97-99,126,137-139,152-162,164,166,169-178,183-184,186-191,200-201,213- 214,216-218,228-232,241,286-291,341-342
1990 75 17-22,53-59,145-150,161-164,199-218,226-236, 255-263,290-292,305-309 none 10,23,29,40-41,61-62,66,69-73,84,86-91,94-95,97,100-106,117-120,125-126,130-131,138-139,150-159,164-181,187-190,192-198,237-239,247-152,275-280,288-290,300-302,304,309-310,314-315,318,322-323,327-328,333
1991 41 1-216 none 221-226,238-241,253- 256
1992 99 11-13 none none
1993 99 151-153,303-304 none none
1994 63 1-46,93-106,118-130,134-138,303-365 (00)070-(13)070 none
1995 50 1-183 none none
1996 100 none none none
1997 45 015-066,099-251 none none
1998 99 309-310,325-327 none none