Figures of Chapter 10: The inflow of highly saline water into the Baltic Sea

Transcription

1 Figures of Chapter 1: The inflow of highly saline water into the Baltic Sea by Wolfgang Matthäus, Dietwart Nehring, Rainer Feistel, Günther Nausch, Volker Mohrholz, Hans Ulrich Lass from the book State and Evolution of the Baltic Sea, A Detailed 5-Year Survey of Meteorology and Climate, Physics, Chemistry, Biology, and Marine Environment Editors: Rainer Feistel, Günther Nausch, Norbert Wasmund Wiley

2 Drogden Sill 5 71 Darss Sill Western Gotland Basin Arkona Basin Bornholm Basin Gdańsk Basin Eastern Gotland Basin 13: Bornholm Deep 33: Gdańsk Deep 71: Gotland Deep : Fårö Deep : Landsort Deep 5: Karlsö Deep Fig. 1.1: Schematic view of the large-scale circulation in the Baltic Sea (from Elken & Matthäus 7, modified). Red arrows denote the inflow of highly saline water and its circulation in the bottom layer.

3 Fig. 1.: Thermohaline stratification between the Darss Sill and the Słupsk Channel in September 5 caused by weak baroclinic inflows.

4 3 R e l a t i v e i n t e n s i t y 1 N u Number m b e r o of f cases c a s e s very strong J A S O N D J F M A M J strong moderate weak no data World War I no data World War II no data 5 15 River runoff / km 3 Fig. 1.3: Major Baltic inflows (MBIs) between 1 and 7 and their seasonal distribution (upper right) shown in terms of their relative intensity (Matthäus & Franck 199; Fischer & Matthäus 199; supplemented and updated by Matthäus a) and fiveyear running means of river runoff to the Baltic Sea (inside the entrance sills) averaged from September to March (shaded). Black boxes on the time axis: MBIs arranged in clusters.

5 1 1 Temperature / o C Oxygen content / ml/l 1 July 1 January 1 July 1 January Fig. 1.: Seasonal variation of temperature T and oxygen concentration O (monthly means and extreme values) of the water penetrating into the Baltic Sea during MBIs (Matthäus & Franck 19).

6 Dec 191/Jan 19 Nov/Dec 1951 Oct/Nov Dec 5 Nov 3 Oct Dec Jan 19-1 Nov 1 Dec - 1 Oct 1 Nov Oct Oct Dec 1975/Jan Dec Dec 1 Jan Jan Jan Jan 3 1 Jan 15 Nov Nov Nov - Preinflow period I n f l o w Precursory period p e r i o d - 1 Nov Dec 1 Jan Jan 15 Jan Jan 15 Jan Fig. 1.5: Rise of the mean Baltic sea level (station Landsort) during precursory and main inflow periods (definition cf. MBI 1975/197) of selected strong and very strong MBIs (Matthäus 1993, modified and updated). Hatched lines mark the MBI start at the Darss Sill.

7 5 A Wind Mean east-component / m/s Seasons with MBI Seasons without MBI B Mean Baltic sea level / cm Seasons with MBI Seasons without MBI 1 July 1 January Fig. 1.: Annual variation of ensemble means of daily east component of the wind in the transition area (upper panel; positive means wind from west) and of daily deviations from the 5-year running means of the Baltic sea level (lower panel) for seasons with and without MBIs (Lass & Matthäus 199).

8 Fig. 1.7: Mean anomaly in sea level pressure fields from August to October during both inflow seasons without (left) and with MBIs (right) (contour interval:. hpa) (Schinke & Matthäus 199).

9 5 A 5 B 5 C Precursory period Inflow period Inflow interval N u m b e r o f c a s e s Fig. 1.: Frequency distributions of the water volumes (in km 3 ) penetrating before the beginning of the MBI at the Darss Sill (A), during the event (B) and during the complete inflow interval (C) (Matthäus & Franck 199).

10 Daily Temperature 7, EGB: NE (57 3'N, 'E): H= m,5, CTD-Data T/ C 5,5 5, Oct 1 Aug 17m m 19m,5, Sep 1997 Jan 3 Aug 3 Fig. 1.9: Daily temperature recorded at three horizons within the near-bottom layer of the Gotland Deep upon the NE position (57 3 N, E, cf. Fig. 3.1, lower right); water depth: m. The recording gap during 199 was fractionally filled with CTD data from the BMP station 71 and their sampling underlines the existing aliasing problem (from Feistel, et al., modified).

11 ATMOSPHERIC CIRCULATION WATER EXCHANGE CENTRAL BALTIC DEEP WATER PRECIPITATION TEMPERATURE SALINITY RIVER RUNOFF OXYGEN NUTRIENTS? MAJOR BALTIC INFLOWS Baroclinic summer inflows CONTAMINANTS Fig. 1.1: Schematic diagram of the influence of variability in atmospheric circulation on the central Baltic deep water (from Matthäus & Nausch 3, modified).

12 T e m p e r a t u r e / o C / Bornholm Deep m Gotland Deep m Farö Deep 15 m o 5 3 Landsort Deep m 3 5 Karlsö Deep 1 m Fig. 1.11: Long-term variation of temperature in the central Baltic deep water.

13 S a l i n i t y / psu Bornholm Deep m / Gotland Deep m Farö Deep 15 m o Landsort Deep m Karlsö Deep 1 m Fig. 1.1: Long-term variation of salinity in the central Baltic deep water.

14 O x y g e n / ml/l / O x y g e n - H S Bornholm Deep m - Gotland Deep m Farö Deep 15 m o - Landsort Deep m - Karlsö Deep 1 m Fig. 1.13: Long-term variation of oxygen and hydrogen sulphide concentrations in the central Baltic deep water (hydrogen sulphide converted into negative oxygen equivalents after Fonselius 199).

15 G o t l a n d D e e p Temperature / o C 1 m 15 m MBI 197 MBI 1997 BSI BSI 1959 MBI 197 BSI m Fig. 1.1: Long-term variation of temperature in three levels of the deep water of the Gotland Deep. Signals of baroclinic summer inflows (BSI) are indicated by small arrows, the effects of MBIs are indicated by heavy arrows.

16 P h o s p h a t e / µmol/l Bornholm Deep m 1 Gotland Deep m Farö Deep 15 m Landsort Deep m Karlsö Deep 1 m Fig. 1.15: Long-term variation of phosphate concentrations in the central Baltic deep water.

17 N i t r a t e + N i t r i t e / µmol/l Bornholm Deep m Gotland Deep m 1 1 Farö Deep 15 m 1 1 Landsort Deep m 1 1 Karlsö Deep 1 m Fig. 1.1: Long-term variation of nitrate concentrations in the central Baltic deep water.

18 A m m o n i u m / µmol/l Bornholm Deep m Gotland Deep m Farö Deep 15 m Landsort Deep m Karlsö Deep 1 m Fig. 1.17: Long-term variation of ammonium concentrations in the central Baltic deep water.

19 1 Hydrogen sulphide/ oxygen [ml/l] Oxygen Phosphate Phosphate [µmol/l] -1 Hydrogen sulphide -1 Hydrogen sulphide/ oxygen [ml/l] Ammonium Oxygen Hydrogen sulphide Nitrate 3 1 Ammonium resp. nitrate [µmol/l] Fig. 1.1: Long-term variations of oxygen and hydrogen sulphide (converted into negative oxygen equivalents) and their influence on the distribution of phosphate (upper panel), nitrate and ammonium in the bottom layer of the Gotland Deep between 199 and 3 (lower panel) (from Nausch et al. 3, supplemented).