Naslov
Quality control and data processing of hourly sea levels in delayed mode – an example from Croatia (station Bakar)

Autori
Međugorac, Iva ; Pasarić, Miroslava ; Orlić, Mirko ; Šepić, Jadranka ; Čupić, Srđan

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, neobjavljeni rad, ostalo

Skup
2nd EuroSea Tide Gauge Network Workshop

Mjesto i datum
Madrid, Španjolska, 04.05.2023. - 05.05.2023

Vrsta sudjelovanja
Radionica

Vrsta recenzije
Nije recenziran

Ključne riječi
Tide gauge, Checks of recorder zero, Hourly series, The Adriatic seiche

Sažetak
Bakar tide-gauge station is the oldest Croatian station, established in 1929. It is equipped with three instruments, two float-type (analog and digital) installed over a stilling well and one radar-type installed in the open air. We will present several types of checks and data-analysis methods used in delayed mode to control quality of hourly data measured with the float instruments: (a) checks of instruments and vertical distances, (b) customary yearly analysis, and (c) a new method of data verification using filtered series from a nearby tide-gauge station. Checks of recorder zero showed that the analog instrument was steady over the years. During the first years of operation the digital instrument had drifts of up to 35 cm which were an indication that it was not properly installed. Geodetic measurements showed that the station is on stable ground and that sea-level series need not be corrected for land movements. Customary yearly data processing is done at the beginning of the current year and is carried out for the previous year. It includes (i) comparison of data measured by the two float-type instruments at Bakar, (ii) calculation of tidal constants and comparison with known values, (iii) inspection of residuals, and (iv) interpolations of short data gaps. In this way we detect and remove errors caused by instrument drifts, time shifts and others. Recently, we have inspected the hourly series (1956–2020) using time series of sea levels band-pass filtered around 22 h (the Adriatic fundamental seiche) and comparing them to the same type of series from the tide-gauge station in Rovinj. Generally, the two time series were highly correlated whereas a few intervals when correlation was small (due to phase shift) pointed to the suspicious data. In this way we have identified seven problematic intervals (in the years 1978–1984) for which the data were corrected. Verified data are published in SEANOE database under license CC-BY-NC (https://doi.org/10.17882/85171).

Izvorni jezik
Engleski

Znanstvena područja
Geofizika

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