DARBINYAN D.S., PURUNDZHAN N.A., SMIRNOV A.S.
“Peter Gaz” Ltd, Russia

One of the main goals of “Peter Gaz” Ltd metocean department is observation of metocean parameters along designed underwater pipeline routes.

According to acting normative documents meteorological (air temperature, humidity, pressure and wind direction, speed and gust) and hydrological (currents speed and direction, wave parameters, water temperature and conductivity, sea level) must be measured. Software supplied by instrument producers and special programs and software for data processing and visualization (t_tide, Ocean Data View), including of own development, are used.

The first stage of data processing is quality control. It includes automated identification of low-quality data and their following expert inspection.
All measured data are presented as time series plots of measured parameters. In some cases smoothing algorithm is used (for example, water and air temperatures, salinity etc).

Statistical analysis is used for currents data. As a result, roses of maximum and mean current velocities, speed and direction histograms and speed by direction frequency tables are presented. In case if observations are performed in tidal seas harmonic analysis is performed: tidal constituents are calculated and on plots measured and tidal (calculated) current velocities and directions are shown. Separately, residual currents are shown.
Progressive-vector diagrams are also presented for currents.

In order to estimate extreme current speed values possible once in N years, Weibul distribution is used. On the bases of observational data, distribution parameters are calculated and distribution curve is plotted.

Usually wave data is presented as time series plots of significant wave height, peak period and peak direction. Also, statistic analysis is performed. Frequency tables for significant wave height and peak period by directions, roses and histograms are given as a result.
Sea level variations are calculated relative to mean sea level for measurement data series. For tidal seas harmonic analyses for every series and for whole measurement period (if possible) are performed. In that case, plots of time series show measured, calculated (tidal) and residual level data. Tables of tidal constituents for level data are also given.

Meteorological parameters are shown as time series plots. But for wind data statistic analysis is also performed. Results are shown in similar way as current statistic analysis figures.

For water salinity and temperature measured by moored instruments, time series are plotted. The same parameters observed during profiling are show either as vertical profiles, or as section.

Shown in described way data of metocean observations give pictorial view of metocean conditions in survey area, allow estimating values of hydrological and meteorological parameters and can be used for modeling results verification.

Oil and gas of Arctic shelf 2008