CoMSBlack 93 international cruise Dataset

CoMSBlack 93 international cruise in the Black Sea was held in April 1993. An intercalibration meetings for physical data acquired during the cruise were held at the Marine Hydrophysical Institute of the Ukrainian Academy of Sciences, Sevastopol, Ukraine, 7 - 10 September and at the Institute of Marine Sciences of the Middle East Technical University, Erdemli, Turkey, 15 - 20 December 1993.

CoMSBlack 93 acquired complete hydrographic, and biochemical data set for the western and northern part of the Black Sea excluding the EEZ of Bulgaria with the participation of Turkey (Bilim and Piri Reis) and Ukraine (Professor Professor Kolesnikov, Professor Vodyanitsky and Metchnikov). Nearly 350 hydrographic stations were occupied to the water depth 500 - 2000 db or to the bottom over the shallower regions. Station spacing was approximately 20 nm and 10 nm in the northwest part of the sea over the slope region. R/V Metchnikov from the Odessa's branch of the Institute of Biology of southern seas Ukrainian Academy of Sciences provided near shore biogeochemical survey in the shallow northwest part of the sea. R/V Professor Vodyanitsky provided biological survey of the region covered by Professor Kolesnikov but on a coarse grid. The cruise was accomplished in two weeks (table 1).
The data set on this server contains only intercalibrated and pooled physical data. Requests for other types of data have to be sent to the data originators.

Table 1

* CTD information from R/V Professor Vodyanitsky and Metchnikov was used only for biochemical data interpretation.

For intercalibration purposes, one station (43°30'N, 31°45'E) was occupied by three ships and the CTD profiles were carried out down to the bottom. Vertical temperature and salinity profiles were measured by different types of CTDs (Istok VII and SBE-9). Their technical specifications are presented in description of the CoMSBlack 92 cruise.

Data from the intercalibration station (N30N45) were first examined to assess their quality. The comparison was done only for data recorded below 1000 db, since spatial and temporal variability at these depths is very small so that the dynamic range is very narrow. These data, as in HB '91, and CoMSBlack 92 proved to be suitable for drift and noise analysis and spike removal.

For Bilim: The CTD data are practically noise-free and there is no evidence of sensor drift for temperature or conductivity, and, as a result, the salinity profiles are also smooth.

For Professor Kolesnikov : The ISTOK VII CTD instrument recorded data which are of good quality, without noise or significant time drift, both in temperature and conductivity/salinity.

For Piri Reis: The data are of good quality, with no differences in the bottom layer. The data from seven stations made by Piri Reis have gaps. These stations are L18L15, L30K45, L50K35, L30L15, M10K20, M10K45, M30L15.

Water samples were obtained on board of Professor Kolesnikov at intercalibration and deep stations for intercalibration of the salinity values measured by the CTDs. The titration of the bottle samples was carried out on board of the R/V Professor Kolesnikov during the cruise using precise salinometer Sokol-3. The results made on board Professor Kolesnikov were found to be consistent with the CTD values within the expected accuracy of the probes.

The first intercalibration test was a comparison of data obtained by different ships. At the common intercalibration station (N30N45). The vertical profiles of the temperature and salinity from three (Professor Prof. Kolesnikov, Piri Reis and Bilim) ships showed a good agreement in general.

The second intercalibration test was to compare CoMSBlack 93 data for the bottom boundary layer, were physical variability has been proved to be small compared to the accuracy of an individual measurements, with the similar data obtained during CoMSBlack 92 and HydroBlack 91 cruises. The results of this comparison illustrating quality of the CTD data are shown in table 2.

After the comparison made using the data from the intercalibration stations, the agreed correction procedures were applied to all the data sets.

For TEMPERATURE: Owing to the fact that the Professor Kolesnikov data were close to the averaged values from the CoMSBlack '93 and other cruises, they were taken as a reference and left unchanged. The Bilim temperatures were decreased by 0.003°C (the mean difference relative to the Professor Kolesnikov data) for all the stations. The value of 0.006°C were added to all the Piri Reis temperature values.

For SALINITY: Due to the good quality of the data, only the Bilim salinities have been changed, by adding the value of the mean difference found in the intercalibration station (0.007 ppt). Salinity values from Professor Kolesnikov were accepted as correct as they were in good agreement with salinities acquired from salinity samples.

No filtering was applied.

Table 2.

Temperatures (°C) and salinities (ppt) in the bottom boundary layer at the intercalibration stations.

When refering to the data, you must acknowledge the source of data which is the Cooperative Marine Science Program for the Black Sea.

Download CoMSBlack 93 Dataset (1523K zip file)

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