Nuku'alofa (Tonga) Site History
History Summary
| Station Name | Nuku'alofa |
|---|---|
| Country | Tonga |
| Latitude | 21° 08.0' S |
| Longitude | 175° 10.0' W |
| WOCE No. | 9051 |
| Time Reference | GMT (hours 00-23) |
| Contributor | The National Tidal Facility (NTF),
Flinders University of South Australia GPO Box 2100, Adelaide, 5001, South Australia |
| Instrument Type | (1990-1994)A.Ott float and well gauge located at same latitude as above, but 175° 12.0' W;
(1993-)Aquatrak acoustic gauge (SEAFRAME) |
| Site of Gauge | |
| Observational Period | 1990 - 2001 |
Reference Level
The sea level heights are referred to the zero point assigned to the NTF tide gauge, which is linked to fixed points on land. Benchmark information is available upon request from the originators. The 1990-1994 Ott data were adjusted to the NTF series by adding -450 mm.
Quality Assessment by the UH Sea Level Center
Comment
The series is based on Ott data from 1990 to 21 January 1993. Gaps in the 1993-94 NTF were replaced by Ott data as noted by '*' below.
The daily and monthly means agree well with an adjacent station, Suva, Fiji and reveal no apparent changes in the reference level except the following: the residuals show a sharp drop during the data gap of 3-5 January, 1993 and the mean level appears low during 1993 and 1994. However, the sharp drop in early January 1993 agrees with the signature at Noumea and Rarotonga and the low trend through 1994 agrees well with Noumea. No evidence was found in tide staff readings to suggest a shift. We assume the drop is real.
| Year | CI(%) | Missing Data | Replaced Gaps or Bad Data | Questionable Fluctuations |
|---|---|---|---|---|
| 1990 | 50 | none | none | none |
| 1991 | 97 | 293-304 | none | 306,308,335 |
| 1992 | 96 | 35-42,118-126 | none | none |
| 1993 | 99 | 3-5 | *(00)322-(00)326 *(00)110-(00)113 | none |
| 1994 | 100 | none | none | none |
| 1995 | 96 | 325-342 | *(00)259-(23)264 | none |
| 1996 | 100 | none | none | none |
| 1997 | 99 | 09 | none | none |
| 1998 | 100 | none | 359(21)-360(05) | none |
| 1999 | 100 | none | none | none |
| 2000 | 100 | none | none | none |
| 2001 | 88 | 12-30,328-354 | none | 316-321 |
