Report from the SMHI monitoring cruise with M/V Meri

Transcription

1 Anna-Kerstin Thell Swedish Meteorological and Hydrological Institute Oceanographic Laboratory Dnr: S/Gbg Report from the SMHI monitoring cruise with M/V Meri Photo: Panu Hänninen Survey period: Principal: Swedish Meteorological and Hydrological Institute (SMHI), Swedish Agency for Marine and Water Management (SwAM). Cooperation partners: Finnish Environment Institute (SYKE) SUMMARY The September cruise, which is part of the Swedish national marine monitoring programme, covered the Skagerrak, the Kattegat, the Sound and the Baltic Proper. Oxygen concentrations close to zero were observed in all deep water areas in the Baltic Proper. Anoxic conditions, when hydrogen sulphide forms, were measured in the Western Gotland Basin from about 7 metres depth, in the Eastern Gotland Basin intermediate at meters and nearest the bottom at BY and at BY1 Gotland from meters. It was still oxygenated nearest bottom at -CTRY-BP but between 7 and 9 meters acute hypoxia was found (dissolved O < ml/l). Areas with acute hypoxia were also found in the Bornholm Basin at meters and in the Eastern and the Western Gotland Basins starting at around -7 meters. In the Arkona Basin the entire water column was well oxygenated, except at BY1 were acute hypoxia was found close to the bottom. The nutrients DIN and DIP were generally depleted in the surface water which is normal at this time of year. In the southwestern Baltic Proper small amounts of phosphate was measured. Surface concentrations of silicate were still above normal in the whole investigated area. The surface water temperature in the investigated area was normal to colder than normal for the season. The salinity in the surface water was normal except from the Skagerak, BY1 and BY9 where it was higher than normal. Next monitoring cruise is scheduled to start in the middle of October. Adress: Sven Källfelts Gata 1 71 Västra Frölunda Telefon: 11-9 E-post: Anna-kerstin.thell@smhi.se WWW:

2 RESULTS The expedition was conducted aboard the Finnish vessel Meri, it started in Åbo on the 1 th of September and ended in Göteborg the 1 th. The winds during the expedition were strong from west in the beginning to weak from east in the end. The strongest wind was in Eastern Gotland basin with 1 m/s. During the expedition net samples of jelly fish was made in order to develop methods for monitoring. The samples were photographed and the images will later be analysed. This report is based on data that have passed a first quality control. When data are published at the national oceanographic data centre some values might have changed after further quality controls have been performed. Data from this cruise will be published as soon as possible on the data center s webpage, normally within one or two weeks after the cruise. Download data here: (only available in Swedish) The Skagerrak The surface water temperature in the Skagerrak was normal for the season and varied between 1. and 1.9 C. The salinity in the surface was slightly higher than normal except for the southern part where it was lower than normal and varied between psu and 3 psu. Thermocline and halocline coincided and was found at depth between and 7 meters in the area. Concentrations of nutrients in the surface water were very low which is normal for this time of year, except for the southern part were the amount of silicate was higher than normal. The level of dissolved inorganic nitrogen, DIN, (which is the sum on nitrate, nitrite and ammonia) was around.3 µmol/l and the concentrations of phosphate varied between.3 and.13 µmol/l. The silicate concentrations were between. and 3.9 µmol/l. Concentrations of dissolved oxygen were normal in the entire water column at all sampled stations. The fluorescence sond on the CTD generally showed higher levels of fluorescence in the upper part of the water column. The Kattegat and the Sound In the Kattegat and the Sound surface water temperature was normal and varied between C, warmest close to the coast of Kattegat at N1 Falkenberg. The surface salinity was also normal and varied from 17. psu in the Sound to 1. psu at N1 Falkenberg. The pycnocline was found at depth between 1 and meters. At W Landskrona and Fladen also a halocline was found at 7-11 meters depth. All concentrations of nutrients were normal for the season in the entire Kattegat and the Sound except for the amount of silicate, which was slightly above normal. In Kattegat, DIN was depleted in the surface water and phosphate concentrations were around.1 µmol/l. The concentration of silicate in the surface water varied between µmol/l. In surface water of the Sound, the concentration of phosphate was. µmol/l, the silicate about 1.3 µmol/l and DIN was 1. µmol/l. Oxygen concentrations close to the bottom in the area were at normal levels between 3.7 and. ml/l in the Kattegat and. ml/l in the Sound.

3 The fluorescence sond at the CTD generally showed higher levels of fluorescence in the upper part of the water column. The Baltic Proper The temperature in the surface water in the Baltic Proper was normal to lower than normal and varied between 13.1 to 1. C. The salinity in the surface water was normal, except for the western and the northern sampling stations were it was slightly above normal, and varied between.-.3 psu. A clear thermocline was found about 1-3 meters in the area. There was also a pycnocline between and 7 meters, in the Arkona basin it was found more shallow, about 3 meters. The dissolved inorganic nitrogen was depleted in the surface water. The amount of phosphate in the surface water was between. and.3 µmol/l, highest in the Arkona and the Bornholm basins. Surface concentrations of silicate were still above normal in the entire Baltic Proper and varied from 11. µmol/l in the Western Gotland Basin to 1. µmol/l in the Hanö Bay. Oxygen concentrations close to zero were observed in all the deep water areas in the Baltic Proper. Anoxic conditions, when hydrogen sulphide forms, were found in the Western Gotland Basin from about 7 metres depth, in the Eastern Gotland Basin intermediate at meters and near the bottom at BY and at BY1 Gotland from meters. It was still oxygenated at the bottom at - CTRY-BP but between 7 and 9 meters acute hypoxia was found (dissolved O < ml/l). Areas with acute hypoxia were found in the Bornholm Basin at meters and in the Eastern and the Western Gotland Basin starting at around -7 meters. In the Arkona Basin the entire water column was well oxygenated, except at BY1 were acute hypoxia was found from meters. Fluorescence measurements with the CTD showed some phytoplankton activity just above the thermocline. Figure 1. Transect showing oxygen and salinity through the Baltic Proper, from the Sound to the Northern part of the Gotland basin.

4 PARTICIPANTS Name From Anna-Kerstin Thell Chief Scientist SMHI Martin Hansson SMHI Johan Håkansson SMHI Sara Johansson SMHI Johan Kronsell SMHI Panu Hänninen SYKE APPENDICES - Track chart - Table over stations, sampled parameters and number of sampling depths - Map showing bottom oxygen concentrations - Vertical profiles for regular monitoring stations - Monthly average surface water plots for regular monitoring stations

5 SMHis hydrografiska stationer Basstation X HELCOM-station Karteringsstation O Karteringsområde SYKEs hydrografiska stationer Basstation ~Y9 ~~ :._BY31 t> 9 BY3 BY :.:.SY1 e BY1 e BCS

6 Date: Time: 11: Ship: Year: Ser Cru Stat Proj Stat Lat Lon Start Start Bottom Secchi Wind Air Air WCWI CZPP No No T T S S P D D H P P N N N A N A S H C C no no code name date time depth depth dir vel temp pres elac hohp de btl e e a a h o o h t t t t m t l i u o o yyyymmdd hhmm m m C hpa aove loy m m l l x x s o o r r r o o k o m m m tueo apt p p t t y y s t i a z n t y 3 u n n hdsb o - s t t p b c b c b c s t t t t t t i v s l d l d l d i a s m i p t 1 1 BPNX3 BAS... BY9 / LL x-x- 1 1 x x - x - x x x x x x x x x x - x - - x 1 BPWX3 BAS... BY3 NORRKÖPINGSDJ x x x - x - x x x x x x x x x x - x - - x 3 1 BPEX BAS... BY FÅRÖDJ x x x - x - x x x x x x x x x x - x - - x 1 BPEX1 BAS... BY1 GOTLANDSDJ x-xx x x - x x x x x x x x x x x x x x x x - 1 BPEX13 BAS... BY x x x x x - x x - x x x x x x x - x BPSE1 BAS... -CTRY-BP x-x- 1 1 x x x x - x x - x x x x x x x - x x x BPWX BAS... BY3 KARLSÖDJ x-x- 1 1 x x x x - x x x x x x x x x x - x x - x 1 BPWK1 BAS... REF M1V xxxx x x x x x x x - x x x x x x x x x - x BPSB7 BAS... BY BORNHOLMSDJ xxx- 1 1 x x x x x x x - x x x x x x x x x x BPSB BAS... BY CHRISTIANSÖ x--x 1 1 x x x x x x x - x x x x x x x x x BPSH BAS... HANÖBUKTEN x x x x x - x x - x x x x x x x - x BPSA3 BAS... BY ARKONA xxx- x x x x - x x - x x x x x x x - x x BPSA BAS... BY x--- x x x x - x x - x x x x x x x - x SOCX39 BAS... W LANDSKRONA x x x x x - x x - x x x x x x x - x - - x 1 1 KAEX9 BAS... ANHOLT E xxxx 1 1 x x x x x x x - x x x x x x x x x x x x 1 1 KANX BAS... N1 FALKENBERG xxxx 7 7 x x x x x x x - x x x x x x x x x KANX BAS... FLADEN x x x x x - x x - x x x x x x x - x SKEX3 BAS... P x x x x x - x x - x x x x x x x - x SKEX1 BAS... Å xxx- 1 1 x x - x x x x - x x x x x x x x x SKEX17 BAS... Å x - x - - x x SKEX1 BAS... Å x x x x x - x x - x x x x x x x - x SKEX1 BAS... Å x - x - - x SKEX1 BAS... Å x x x x x - x x - x x x x x x x - x FIBG7 BAS... SLÄGGÖ xxx- 9 9 x x x x - x x - x x x x x x x - x - - -

7 N 9 N.9 N 7 N N N N H S H S H S H S ml/l 9 E 11 E 13 E 1 E 17 E 19 E 1 E 3 E E 7 E

8 STATION BY9 / LL19 SURFACE WATER (-1 m) 1 1 Annual Cycles Mean 1-1 St.Dev PO mol/l O saturation % OXYGEN IN BOTTOM WATER (depth >= 1 m) O ml/l O ml/l Month Year

9 Vertical profiles BY9 / LL19 September Mean 1-1 St.Dev Oxygen ml/l PO mol/l

10 STATION BY3 NORRKÖPINGSDJ SURFACE WATER (-1 m) 1 1 Annual Cycles Mean 1-1 St.Dev PO mol/l O saturation % OXYGEN IN BOTTOM WATER (depth >= 17 m) O ml/l O ml/l Month Year

11 Vertical profiles BY3 NORRKÖPINGSDJ September Mean 1-1 St.Dev Oxygen ml/l PO mol/l

12 STATION BY FÅRÖDJ SURFACE WATER (-1 m) 1 1 Annual Cycles Mean 1-1 St.Dev PO mol/l O saturation % OXYGEN IN BOTTOM WATER (depth >= 17 m) 1 O ml/l Month O ml/l Year

13 Vertical profiles BY FÅRÖDJ September Mean 1-1 St.Dev Oxygen ml/l PO mol/l

14 STATION BY1 GOTLANDSDJ SURFACE WATER (-1 m) 1 1 Annual Cycles Mean 1-1 St.Dev PO mol/l O saturation % OXYGEN IN BOTTOM WATER (depth >= m) 1 O ml/l Month O ml/l Year

15 Vertical profiles BY1 GOTLANDSDJ September Mean 1-1 St.Dev Oxygen ml/l PO mol/l

16 STATION BY1 SURFACE WATER (-1 m) 1 1 Annual Cycles Mean 1-1 St.Dev PO mol/l O saturation % OXYGEN IN BOTTOM WATER (depth >= 1 m) 1 O ml/l Month O ml/l Year

17 Vertical profiles BY1 September Mean 1-1 St.Dev Oxygen ml/l PO mol/l

18 STATION BY3 KARLSÖDJ SURFACE WATER (-1 m) 1 1 Annual Cycles Mean 1-1 St.Dev PO mol/l O saturation % OXYGEN IN BOTTOM WATER (depth >= 1 m) 1 O ml/l 1 O ml/l Month Year

19 Vertical profiles BY3 KARLSÖDJ September Mean 1-1 St.Dev Oxygen ml/l PO mol/l

20 STATION REF M1V1 SURFACE WATER (-1 m) 1 1 Annual Cycles Mean 1-1 St.Dev PO mol/l O saturation % OXYGEN IN BOTTOM WATER (depth >= 17 m) 1 O ml/l 1 O ml/l Month Year

21 Vertical profiles REF M1V1 September Mean 1-1 St.Dev Oxygen ml/l PO mol/l

22 STATION BY BORNHOLMSDJ SURFACE WATER (-1 m) 1 1 Annual Cycles Mean 1-1 St.Dev PO mol/l O saturation % OXYGEN IN BOTTOM WATER (depth >= m) 1 O ml/l Month 1 O ml/l Year

23 Vertical profiles BY BORNHOLMSDJ September Mean 1-1 St.Dev Oxygen ml/l PO mol/l

24 STATION BY CHRISTIANSÖ SURFACE WATER (-1 m) 1 1 Annual Cycles Mean 1-1 St.Dev PO mol/l O saturation % OXYGEN IN BOTTOM WATER (depth >= m) 1 O ml/l Month 1 O ml/l Year

25 Vertical profiles BY CHRISTIANSÖ September Mean 1-1 St.Dev Oxygen ml/l PO mol/l

26 STATION HANÖBUKTEN SURFACE WATER (-1 m) 1 1 Annual Cycles Mean 1-1 St.Dev PO mol/l O saturation % OXYGEN IN BOTTOM WATER (depth >= 7 m) O ml/l Month O ml/l Year

27 Vertical profiles HANÖBUKTEN September Mean 1-1 St.Dev Oxygen ml/l PO mol/l

28 STATION BY ARKONA SURFACE WATER (-1 m) 1 1 Annual Cycles Mean 1-1 St.Dev PO mol/l O saturation % OXYGEN IN BOTTOM WATER (depth >= m) 1 O ml/l 1 O ml/l Month Year

29 Vertical profiles BY ARKONA September Mean 1-1 St.Dev Oxygen ml/l PO mol/l

30 STATION BY1 SURFACE WATER (-1 m) 1 1 Annual Cycles Mean 1-1 St.Dev PO mol/l O saturation % OXYGEN IN BOTTOM WATER (depth >= m) 1 O ml/l 1 O ml/l Month Year

31 Vertical profiles BY1 September Mean 1-1 St.Dev Oxygen ml/l PO mol/l

32 STATION W LANDSKRONA SURFACE WATER (-1 m) 1 1 Annual Cycles Mean 1-1 St.Dev PO mol/l O saturation % OXYGEN IN BOTTOM WATER (depth >= m) 1 O ml/l 1 O ml/l Month Year

33 Vertical profiles W LANDSKRONA September Mean 1-1 St.Dev Oxygen ml/l PO mol/l

34 STATION ANHOLT E SURFACE WATER (-1 m) 1 1 Annual Cycles Mean 1-1 St.Dev PO mol/l O saturation % OXYGEN IN BOTTOM WATER (depth >= m) 1 O ml/l 1 O ml/l Month Year

35 Vertical profiles ANHOLT E September Mean 1-1 St.Dev Oxygen ml/l PO mol/l

36 STATION N1 FALKENBERG SURFACE WATER (-1 m) 1 1 Annual Cycles Mean 1-1 St.Dev PO mol/l O saturation % OXYGEN IN BOTTOM WATER (depth >= m) 1 O ml/l 1 O ml/l Month Year

37 Vertical profiles N1 FALKENBERG September Mean 1-1 St.Dev Oxygen ml/l PO mol/l

38 STATION FLADEN SURFACE WATER (-1 m) 1 1 Annual Cycles Mean 1-1 St.Dev PO mol/l O saturation % OXYGEN IN BOTTOM WATER (depth >= 7 m) 1 O ml/l 1 O ml/l Month Year

39 Vertical profiles FLADEN September Mean 1-1 St.Dev Oxygen ml/l PO mol/l

40 STATION P SURFACE WATER (-1 m) 1 1 Annual Cycles Mean 1-1 St.Dev PO mol/l O saturation % OXYGEN IN BOTTOM WATER (depth >= 7 m) 1 O ml/l 1 O ml/l Month Year

41 Vertical profiles P September Mean 1-1 St.Dev Oxygen ml/l PO mol/l

42 STATION Å17 SURFACE WATER (-1 m) 1 1 Annual Cycles Mean 1-1 St.Dev PO mol/l O saturation % OXYGEN IN BOTTOM WATER (depth >= 3 m) 1 O ml/l 1 O ml/l Month Year

43 Vertical profiles Å17 September Mean 1-1 St.Dev Oxygen ml/l PO mol/l

44 STATION Å1 SURFACE WATER (-1 m) 1 1 Annual Cycles Mean 1-1 St.Dev PO mol/l O saturation % OXYGEN IN BOTTOM WATER (depth >= 1 m) 1 O ml/l 1 O ml/l Month Year

45 Vertical profiles Å1 September Mean 1-1 St.Dev Oxygen ml/l PO mol/l

46 STATION Å13 SURFACE WATER (-1 m) 1 1 Annual Cycles Mean 1-1 St.Dev PO mol/l O saturation % OXYGEN IN BOTTOM WATER (depth >= m) 1 O ml/l 1 O ml/l Month Year

47 Vertical profiles Å13 September Mean 1-1 St.Dev Oxygen ml/l PO mol/l

48 STATION SLÄGGÖ SURFACE WATER (-1 m) 1 1 Annual Cycles Mean 1-1 St.Dev PO mol/l O saturation % OXYGEN IN BOTTOM WATER (depth >= m) 1 O ml/l 1 O ml/l Month Year

49 Vertical profiles SLÄGGÖ September Mean 1-1 St.Dev Oxygen ml/l PO mol/l