Baltic Sea

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with one another and with the salt content of the deep EGB. To be able to cross-correlate the dierent data sets (modelled and measured volume and salt transports), 5-day means of the hourly and daily data sets were created. To make things easier, short names are introduced for the dierent data sets and an overview given in the abbreviations: for the Stolpe Channel 5-day mean volume transports both eastward/westward and also solely eastward with salinities greater-than-or-equal 12 g/kg will be called VoltrpSF 12 and VoltrpSF 12P , respectively. Salt transports will be referred to in the same manner: SaltrpSF 12 and SaltrpSF 12P . Daily volume transports through the Stolpe Channel of the data set greater than 9.5 kg/m 3 will be called VoltrpSF 9.5 for both eastward and westward transports, and VoltrpSF 9.5P for only eastward transports. Estimated daily deep volume transports from ADCP measurements, eastward and westward, will be called VoltrpSF ADCP . The 5-day mean volume and salt transports in the Gdansk Basin, in both northerly and southerly (positive and negative transports), as well as only southerly directions (negative transports), will be called: Voltrp55 12 , Saltrp55 12 and Voltrp55 12N , Saltrp55 12N . The 5-day mean northerly and southerly and solely northerly (positive) volume and salt transports through the Hoburg Channel at 56 ◦ N will be called Voltrp56 12 , Saltrp56 12 and Voltrp56 12P , and Saltrp56 12P in the following. The 5-day mean salt content of the deep Eastern Gotland Basin below 170 m will be called SalEGB 170 . The results of the cross-correlations are compiled in Table 4.2. The 15 day lag between the Stolpe Channel and the EGB (Table 4.2) implies that by estimating the distance between the two locations (about 350 km), water is transported with a velocity of around 27 cm/s. This is in fact much faster than the average calculated velocities shown in Fig. 4.18. By looking at the correlations altogether (Table 4.2) the following implications on the pathways of the deep water can be made. It seems that water from the Stolpe Channel more often takes the direct pathway, transporting water directly into the EGB (implied from no lag and a correlation coecient with modelled volume transports of 0.95). Water re-directed through the Gdansk Basin is possibly re-circulating there before being transported through the northern parts of the Gdansk Basin towards the Hoburg Channel. From there it is transported directly into the EGB, implied by the high correlation between the Hoburg Channel and the EGB and the absence of a lag. Although, it is possible that smaller lags are not captured or probably ltered out by the 5-day means, as smaller lags cannot be resolved with this method. The lag between the measured data in the Stolpe Channel and the Hoburg Channel of 20 days 74
needs some explanation, since the lag between measured transports and the salt content of the EGB have only a lag of 15 days, which corresponds with the second peak and same lag between VoltrpSF ADCP and the salt content of the EGB. The 20 day lag could be caused by water masses which leave the Stolpe Channel towards the deepest pathway but are split and take a detour through the western part of the Gdansk Basin rst. The third peak of no lag could be the result of internal seiches, which have a period of 2 days (Samuelsson and Stigebrandt, 1996). Cumulative Volume through Stolpe Channel − 5−day means of salinity > 12 g/kg Cumulative Volume through Stolpe Channel − 5−day means of salinity > 12 g/kg Volume (km 3 ) 3500 3000 2500 2000 1500 1000 pos and neg pos neg Volume (km 3 ) 500 400 300 200 100 pos and neg pos neg 500 0 −500 0 −100 29/05/01 11/10/02 23/02/04 07/07/05 19/11/06 02/04/08 Date (dd/mm/yy) (a) 2002 −2009 03/05/06 22/06/06 11/08/06 30/09/06 19/11/06 08/01/07 Date (dd/mm/yy) (b) May 2006 −March 2007 120 100 Cumulative Volume through Stolpe Channel − 5−day means of salinity > 12 g/kg pos and neg pos neg 80 Volume (km 3 ) 60 40 20 0 −20 20/09 30/09 10/10 20/10 30/10 09/11 19/11 29/11 09/12 19/12 29/12 Date in 2006 (dd/mm) (c) September to December 2006 Figure 4.21: Cumulative positive (eastward, red), negative (westward, blue) and both positive/negative (black) volume (km 3 ) through Stolpe Channel at 17.5 ◦ E for salt ≥ 12 g/kg; position is marked in Fig. 4.18. Note, scales between plots dier. Volume and Salt transports (calculated from 5-day means) are the positive volume and salt transports through the Stolpe Channel and Hoburg Channel taken from Fig. 4.21, Fig. 4.22 and Fig. 4.25, the negative is the southerly transport through the Gdansk Basin from Fig. 4.23 75
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No 88 2012 Spatiotemporal Scales of
Page 3 and 4:
Meereswissenschaftliche Berichte MA
Page 5 and 6:
Abstract The Baltic Sea is surround
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Contents Abstract Contents List of
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Acknowledgement 109 Appendix 111 vi
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M-7/M-8 Mesodyn hydrographic snapsh
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List of Figures 1.1 Baltic Sea - ba
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4.32 Regression sea level dierence
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1. Introduction 1.1 Investigations
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circulation above topographic anks
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58 o N 190 230 210 100 75 100 100 7
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y 'new' deep water. For instance, i
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events. During and after such event
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this inow event was classied as 'mo
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Scale (PSS-78), roughly by 0.5%, as
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(Acoustic Doppler Current Proler) a
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for the southernmost zonal section
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whereas the length of the NE time s
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have a thickness of only 1.5 m in o
Page 39 and 40: dependent salt volumes for the deep
Page 41 and 42: 7 6.5 a Temperature ( o C) 6 5.5 5
Page 43 and 44: Potential Temperature ( o C) 8 7 6
Page 45 and 46: inowing waters masses with variable
Page 47 and 48: following these bounds will be used
Page 49 and 50: 60 80 100 −45 −50 −55 Pressur
Page 51 and 52: Monitoring Station BMP271 60 80 100
Page 53 and 54: Date 31.8.1997, 03.11.1997, 03.11.1
Page 55 and 56: 190 a 200 Depth (m) 210 220 230 240
Page 57 and 58: Date (ID) 〈S〉 V (g/kg) 〈θ〉
Page 59 and 60: deviation of the temperature uctuat
Page 61 and 62: 4. The Deep Circulation in the EGB
Page 63 and 64: Depth (m) 50 100 150 200 17 16 4.6
Page 65 and 66: For this reason, the displayed temp
Page 67 and 68: 6.4 6.3 178 m 208 m 223 m Daily Tem
Page 69 and 70: The deep parts of the basin are exp
Page 71 and 72: On the 29 September 2006 between 60
Page 73 and 74: In the geostrophic balance horizont
Page 75 and 76: captured eastward velocities up to
Page 77 and 78: Figure 4.11: Modelled current veloc
Page 79 and 80: SFS and SFN. At the southern ank a
Page 81 and 82: Mean Volume Transports Mean Volume
Page 83 and 84: 160 170 180 Volume of EGB below 170
Page 85 and 86: Basin 55.9 ◦ N. From there the bo
Page 87 and 88: Volume transports (km 3 /d) 15 10 5
Page 89: Gdansk Basin happened a few weeks e
Page 93 and 94: and Fig. 4.24 and displayed in Tabl
Page 95 and 96: Salt (t) 8 6 4 2 0 2 4 6 8 x 10 10
Page 97 and 98: Time Period Stolpe Channel at 17.5
Page 99 and 100: Modelled volume transport through S
Page 101 and 102: discovered that most of the varianc
Page 103 and 104: to the right (perpendicular) to the
Page 105 and 106: of salty and often well oxygenated
Page 107 and 108: Depth (m) 40 45 50 55 60 4 3 2 1 0
Page 109 and 110: a correlation coecient of R=-0.68 a
Page 111 and 112: 5. Discussion and Conclusions 5.1 D
Page 113 and 114: graphic cross-sections, conducted i
Page 115 and 116: direction as the wind. The deep lay
Page 117 and 118: Bibliography Axell, L. B., 1998: On
Page 119 and 120: Griffies, S. M., R. C. Pacanowski,
Page 121 and 122: Matthäus, W., 1993: Major inows of
Page 123 and 124: Rubio, A., D. Gomis, G. Jordà and
Page 125 and 126: Zhurbas, V., I. Oh and V. Paka, 200
Page 127 and 128: Appendix Current speed and directio
Page 129 and 130: Current speed and direction (cm/s)
Page 131 and 132: 2 1.5 1 Cumulative volume through S
Page 133 and 134: Volume (km 3 ) 2.5 2 1.5 1 0.5 0
Page 135 and 136: 10 3 Regional Wind 7 Power Spectra
Page 137 and 138: NE along−slope at 178m 10 2 10 1
Page 139 and 140: Meereswissenschaftliche Berichte MA
Page 141 and 142:
26 (1997) Lakaschus, Sönke: Konzen
Page 143 and 144:
51 (2002) Wasmund, Norbert; Pollehn
Page 145 and 146:
78 (2009) Wasmund, Norbert; Pollehn
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