Cruise Report R/V "ALKOR" Cruise- No. HE-35 ( AK111 ) 1 February - 13 February 11 This report is based on preliminary data! an der Universität Rostock Seestraße 15 D-1119 Rostock- GERMANY Tel +9-31-5197- Fax +9-31-5197
Cruise No AL-35 ( AK111 ) 1. Cruise No.: AL-35 ( AK111 ). Dates of the cruise: from 1//11 to 13//11 3. Particulars of the research vessel: Name: Nationality: Germany Operating Authority: Leibniz Institute of Marine Sciences at Kiel University ( IFM - GEOMAR ), 1 Kiel. Geographical area in which ship has operated: Baltic Sea between Kiel Bight and central Gotland Sea 5. Dates and names of ports of call //11 Kiel - //11 Saßnitz - 9//11 Slite 11-1//11 Saßnitz. Purpose of the cruise Joint cruise for Monitoring in the frame of the COMBINE program of HELCOM and long term observation program of IOW 7. Crew: Name of master: J.P. Lass Number of crew: 1. Research staff: Chief scientist: Klaus Nagel Participants : 1/ - 13//11 Jan Donath Ingo Schuffenhauer Ines Hand Erika Trost Ursula Hennings Andrea Tschakste Lars Kreuzer 1/ 5//11 Arkadiusz Lis Sven Trinkler 5/ - 13//11 Uwe Hehl David Meyer Hildegard Kubsch Verona Vandieken 9. Co-operating institutions: All institutions dealing with the COMBINE program of HELCOM - / 13 -
Cruise No AL-35 ( AK111 ) 1. Scientific equipment : CTD water samplers plankton net 11. General remarks and preliminary results The cruise AL35 was a joint cruise between the German contribution to the COMBINE program of HELCOM and the long term data series of IOW. The area under investigation covered the Baltic Sea between Kiel Bight and the central Gotland Basin as shown in the attached maps. Marine meteorological, hydrographic, chemical and biological investigations were performed at 9 stations. The measurements were supplemented by continuous registration of standard meteorological parameters as well as surface water temperature and salinity. For selected stations, which are characteristic for different regions of the Baltic Sea, preliminary data of hydrographic and hydrochemical parameters in the surface and the near-bottom layer are compiled in the attached tables. These results are also compared with mean values calculated from the measurements performed during the February cruises of the years 1993 to 7. The weather during the cruise was dominated by some high and low pressure areas passing the area under investigation. Strong pressure gradients caused some heavy storms and several windy days preventing the sampling at some stations ( see attached figure ). Compared to the last years air temperature was rather moderate varying between C and + C during most of the time. Only between //11 and //11 air temperatures up to +1 C and on 1//11 of -5 C to - C had been observed. Although there were a few days with some sunny periods, the sky was clouded almost all the time. Salinity in the surface layer was within the values expected from long term measurements in all regions of the Baltic Sea and varied between 7 - g/kg except Kiel and Mecklenburg Bight, where 1-15 g/kg were measured. A halocline was observed between m and 5 m in the Arkona Basin, between 5 m and m in the Bornholm Basin and in the Eastern Gotland Basin. Salinities found in the bottom layer in the central areas of the Baltic Sea are in the range expected from long term observations and varied around 1. Only salinities in the bottom layer of the Arkona basin are lower than expected ( 1-13 g/kg ). No indication for inflow of high saline water from the North Sea had been detected. The western Baltic Sea and the Arkona basin were well oxygenated down to the sea floor with oxygen concentrations around 7 ml/l to 9 ml/l at most stations. Oxygen concentration in the Bornholm Basin dropped below ml/l at depths exceeding 7 m, but Oxygen is detectable at the bottom layer of all stations in this area. Anoxic conditions had been observed only in the central eastern Gotland Basin at depths below 11 m. In the bottom layer of the eastern Gotland Basin concentrations of up to 5.1 mg/l H S were found, which is slightly more the value measured last year at the same time. - 3 / 13 -
Cruise No AL-35 ( AK111 ) Nitrate concentrations in the surface layer were normal for this time of the year and vary between 3 µmol/l and almost 5 µmol/l, which is within the range expected from long term observations. Phosphate concentrations in the surface layer were found between.5 µmol/l and. µmol/l and are in good agreement with the values expected from IOW's long term data series. In the bottom layer concentrations of nitrate and phosphate are controlled by the presence of oxygen or hydrogen sulphide and were found in the expected range. Due to the ongoing stagnation phosphate concentrations at the bottom of the Eastern Gotland Basin were higher than that measured one year ago ( > µmol/l ) and correlate with relatively high amounts of H S ( >5 mg/l H S ). Samples for the determination of trace metals ( 15 stations ), HCH, CKW/PAK ( 11 stations ) and Phyto- and Zooplankton ( 11 stations ) were taken for later analysis in the laboratory. At station TF71, an automatic analyser fixed to the CTD system is used determine the in situ concentration of Fe(II). The method based on a spectrophotometric assay using Ferene as reagent. Two profiles in the range between surface and m were taken, lowering the analyser with a speed of.1 m/s. Additional discrete controls were sampled for later analysis in the laboratory. During the cruise a profiling mooring has been recovered at position 57 19.' N, 7.9' E Klaus Nagel Scientist in charge Attachments : - station charts - figure showing air pressure gradients during the cruise - tables of preliminary results for selected stations (surface layer and near bottom layer) - comparison of actual data with mean values calculated from the measurements during the February cruises of the years 1993 7 (surface layer and near bottom layer) - transect of temperature, salinity and oxygen concentration between Kiel Bight and Gotland Sea - map showing oxygen concentrations in near the bottom water layer ( hydrogen sulphide concentration is given as negative O equivalents ) - / 13 -
Cruise No AL-35 ( AK111 ) AK111 / map 1 monitoring 1..11-13..11 5 stations / repeated stations TF3 TF31 TF TF1 TF11 TF1 TF TF TF1 TFO5 Longitude [ ] TF TF3 TF1 TF115 TF9 TF11 TF15 TF113 TFO11 TF1 TF13 TF111 ABBoje TF11 TF11 TF19 TF15 TF15 TF15 OBBoje TF1 TF1 TF1 5 5 5 5 5 55 55 55 55 55 5 5 5 Latitude [ ] -5-1 -15 - -5-3 -35 - -5-5 -55 - -5-7 -75-11 Department Physical Oceanography Jan Donath Leibniz Institute for Baltic Sea Research 1. 1.5 11. 11.5 1. 1.5 13. 13.5 1. 1.5 15. - 5 / 13 -
Cruise No AL-35 ( AK111 ) AK111 / map monitoring 1..11-13..11 5 stations / repeated stations TF TF1 TF13 TF1 TF1 TF Longitude [ ] TF55 TF59 15. 15.5 1. 1.5 17. 17.5 1. 1.5 19. 19.5..5 1. 1.5. TF53 TF3 TF71 55 5 5 57 57 5 5 59 59 Latitude [ ] 11 Department Physical Oceanography Jan Donath Leibniz Institute for Baltic Sea Research -5-5 -75-1 -15-15 -175 - -5-5 -75-3 -35-35 -375 - -5-5 - / 13 -
Cruise No AL-35 ( AK111 ) - 7 / 13 -
Cruise No AL-35 ( AK111 ) Preliminary results of hydrographic and hydrochemical parameters at selected stations - surface layer - Station Stat.Name Temp. Salinity NO 3 *) PO SiO O Date Stat.No. **) C µmol/l µmol/l µmol/l ml/l Kiel Bight 1//11 Mecklenburg Bight //11 Arkona Basin 3//11 Bornholm Deep 1//11 Stolpe Channel 1//11 SE Gotland Basin 1//11 Gotland Deep 7//11 Fårö Deep TF3 5 TF1 TF113 1 TF13 7 TF 5 TF59 TF71 TF.31 15.9.5.5 15..93.19 11.5 5.75.5 1.1 9.7 1.11 7.5 3.9.5 1.3 9.37 1.9 7.19 3.5.53 15.1. 1.75 7.19 3..5 1. 9.5 1,9 7.7 3..5 1.7 9.. 7.3 3.5.57 1.5 9. Landsort Deep TF Karlsö Deep TF5 *) NO 3 is given as sum of NO 3 - and NO - **) see attached maps (in most samples NO - was present only in traces) - / 13 -
Cruise No AL-35 ( AK111 ) Preliminary results of hydrographic and hydrochemical parameters at selected stations near bottom layer - Station Stat.Name Depth Temp. Salinity NO 3 *) PO SiO O Date Stat.No. **) m C PSU µmol/l µmol/l µmol/l ml/l Kiel Bight 1//11 Mecklenburg Bight //11 Arkona Basin 3//11 Bornholm Deep 1//11 Stolpe Channel 1//11 SE Gotland Basin 1//11 Gotland Deep 7//11 Fårö Deep TF3 5 TF1 TF113 1 TF13 7 TF 5 TF59 TF71 TF 17 1.1 1.5 5.7.5 15.3.97 3. 19.1.37.7 1. 7. 5.9 1.9.7.9.5.7 7 7. 15.39 7. 1.97 59.5.13 9.3 11.7 7.7 1. 3.3 3.3 5.3 11.15 7.7.13 3.9 1.5 3. 1.3 -. 79.3 -.1 ( H S ) Landsort Deep TF Karlsö Deep TF5 *) NO 3 is given as sum of NO - - 3 and NO (in most samples NO - was present only in traces) **) see attached maps H S was converted into negative O equivalents - 9 / 13 -
Cruise No AL-35 ( AK111 ) Selected stations / February cruises : near-surface layer Temperature ( C ) 1 Salinity 1 1 1 1 1 Nitrate ( µmol/l ),9 Phosphate ( µmol/l ),,7,,5,,3,,1 9,5 Oxygen ( ml/l ) 9,,5, TF3 TF1 TF113 TF13 TF TF59 TF71 TF TF TF5 K. Nagel \ st_11s \ 1//11 Means & s.dev. February cruises 1993-7 Monitoring cruise February 1 Monitoring cruise February 11-1 / 13 -
Cruise No AL-35 ( AK111 ) Selected stations / February cruises : near-bottom layer Temperature ( C ) Salinity 1 1 1 1 1 1 1 Nitrate ( µmol/l ) 1 7 Phosphate ( µmol/l ) 5 3 1 Oxygen ( ml/l ) **) - - - TF3 TF1 TF113 TF13 TF TF59 TF71 TF TF TF5 **) : H S was converted to negative O equivalents K. Nagel \ st_11b \ 1//11 Means & s.dev. February cruises 1993-7 Monitoring cruise February 1 Monitoring cruise February 11-11 / 13 -
Cruise No AL-35 ( AK111 ) AK111 Kiel Bight - Gotland Sea 1..11 13: - 1..11 15:9 UTC TF3 TF31 TF1 TF11 TF1 TF TF TF1 TF3 TF115 TF11 TF113 TF15 TF1 TF1 TF15 TF1 TF1 TF TF1 TF13 TF1 TF TF59 TF55 TF53 TF3 TF71-1 -3 Depth [m] -5-7 -9-11 -13-15 -17-19 -1-3 Temperature [ C] 7 5 3 1-5 5 1 15 5 3 35-1 -1 Depth [m] -3-5 -7-9 -11-13 -15-17 -19-1 -3 Salinity [psu] -5 5 1 15 5 3 35 5 3 1 19 1 17 1 15 1 13 1 11 1 9 7-1 -3 Depth [m] -5-7 -9-11 -13-15 9 7 5 5.srf -17-19 -1-3 Oxygen [ml/l] -5 5 1 15 5 3 35 Distance [n.m.] 11 Leibniz Institute for Baltic Sea Research, Department Physical Oceanography Jan Donath 3 1-1 / 13 -
Cruise No AL-35 ( AK111 ) AK111 / map O monitoring 1..11-13..11 oxygen bottom - concentration [ml/l].97 7. 7. 9.1.7 9.5 9.3. Longitude [ ].13 3.3 1.5 -.1(HS) Gotland 5 55 5 57 5 59 Latitude [ ] LATVIA DENMARK SWEDEN Öland Ystad -3 - -9-1 -15-1 -1 - -7 Bornholm POLAND Gdynia Kaliningrad -3-33 -3-39 - -5 - -51-5 GERMANY 11 Department Physical Oceanography Jan Donath Leibniz Institute for Baltic Sea Research 1 11 1 13 1 15 1 17 1 19 1-13 / 13 -