Hans Burchard, Frank Janssen, Hans Ulrich Lass, Volker Mohrholz, Hannes Rennau, and Lars Umlauf
description
Transcript of Hans Burchard, Frank Janssen, Hans Ulrich Lass, Volker Mohrholz, Hannes Rennau, and Lars Umlauf
Hans Burchard, Frank Janssen, Hans Ulrich Lass, Volker Mohrholz, Hannes Rennau,
and Lars Umlauf
Leibniz Institute for Baltic Sea Research Warnemünde, Germany
Internal technical support: Toralf Heene, Günter Plüschke, Dietmar Rüss, Ingo
Schuffenhauer
External scientific collaboration: Lars Arneborg, Karsten Bolding, Volker Fiekas,
Frank Gerdes, Michaela Knoll, Hartmut Prandke, Jürgen Sellschopp
Status of the QuantAS-Off regional scale dynamical studies
Kriegers Flak
Motivation: wind farms in the Western Baltic Sea
Western Baltic Sea monitoring stations
Darss Sill: 19 m
+
Drogden Sill: 8 m
+MARNET (IOW/BSH)
Farvandsvæsenet
baroclinic barotropic
Inflows over Drogden Sill
surface
bottom
Source: Farvandsvæsenet
Where does the Sound plume go ?
?
5 days
15 days
31 days
Sound lock-exchange experiment with GETM
Main plume goes via northof Kriegers Flak: Is this real ?
Bottom salinity: 8 – 25 psu
Burchard et al., 2005
Plume passing Kriegers Flak (Feb 2004)
Burchard et al., 2005
For more details, seeSellschopp et al., 2006
sum m er heating
overflow soverflow s
outflow s
seasonal therm ocline
w inter coo ling
win
ter
sum
mer
in terna lm ix ing
perm anent ha locline
uplift
in terleaving
in terna lwave m ixing
bottomcurrententra inm ent
surface wavem ix ing
boundarym ix ing
convectiveentra inm ent
shear-inducedentrainm ent
differentia ladvection
riverrunoff
w ind stress
coasta lupw elling
sun
Baltic Sea vertical mixing processes
How would offshore wind farm foundations affect this ?
Reissmann et al., 2007
Role of vertical mixing for the Baltic Sea ecosystem
GETM Western Baltic Sea hindcast
Burchard et al, 2007
GETM Western Baltic Sea hindcast
GETM Western Baltic Sea hindcast
Model validation: Darss Sill
Burchard et al, 2007
Nov 2005: Velocity structure of dense bottom current
Ship A:TL-ADCP
Ship B: Microstructure
View
1 km
Flow
Eastcomp.
Northcomp.
Can we explain the flow structure ?
Umlauf et al., 2007
Arneborg et al., 2007: Entrainment laws for each location
GETM 2DV Slice Model: Transverse gravity current structure
Umlauf et al., in prep.
QuantAS – Quantification of water mass transformations in the Arkona Sea
11.0 11.5 12.0 12.5 13.0 13.5 14.0 14.5 15.0 15.5
Longitude [deg]
54.2
54.4
54.6
54.8
55.0
55.2
55.4
55.6
55.8
56.0
56.2La
titud
e [d
eg] Skanör
Viken
Oresound
KFSE
KFN
BGE
DS
AB
FB
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
Depth[m ]
BornholmBasin
ArkonaBasin
Pom eranian Bight
DarssSill
Fehm arn Belt
Rønne Bank
Bornholm-gatt
Drogden Sill
KriegersFlak
Adlergrund
Oderbank
Time series stations
Mohrholz et al., in prep.
QuantAS – Quantification of water mass transformations in the Arkona Sea
Moored devices
SeabirdMicrocat
SeabirdMicrocat
SeabirdMicrocat
SeabirdMicrocat
SeabirdMicrocat
SeabirdSeacat
/////////////////////////////////////////////////////////////////////////////
31
34
36
21
26
Anchor 200kg
200kg
MC
MC
MC
MC
MC
10
Depth(m)
8
Seac
at No
.
ø108. 5cm
M2005-12XT6000
BENTHO
S875
Bouyancy
BenthosReleaser
Quantas
Ropebox
//////////////////////////////////////////////////////////////////////////////////////////////
TR6000
ADCP
Leinenbox
40
35
Releaser
TR6000
25
10
Depth (m)
0
80m Groundrope
Seacat
3 0
Seac
at N
o.
Seacat Seac
at N
o.
500 Bouyancy
20kg
Seacat
Seacat Seac
at N
o.Se
acat
No.
Argos-transponder
30kg
PLÜ.
Bouyancy
08.03.2004
Kriegers Flak North Kriegers Flak South
Mohrholz et al., in prep.
QuantAS – Quantification of water mass transformations in the Arkona Sea
Salinity time series
-30
-20
-10
0
-20
0
-10
0
Salinity - Kriegers Flak North
Salinity - Drogden Sill
Salinity - Darss Sill
Jan
05
Feb
05M
rz 0
5
Apr 0
5
Mai
05
Jun
05
Jul 0
5
Aug
05
Sep
05
Okt
05
Nov
05
Dez
05
Jan
06
Feb
06M
rz 0
6
Apr 0
6
Mai
06
Jun
06
Jul 0
6
Aug
06
Sep
06
Okt
06
Nov
06
Dez
06
5678910111213141618202224
Mohrholz et al., in prep.
QuantAS – Quantification of water mass transformations in the Arkona Sea
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19D istance [nm ]
Log10(D iss ip . ra te [W /kg ]) (contour) / S igm aT [kg/m ³] (iso lines)
-40
-30
-20
-10
0
Dep
th [m
]
55 .09 55.10 55 .11 55.12 55 .13 55 .14 55.15 55.16La titude [deg ]
Log10(D iss ip . ra te [W /kg ]) (contour) / S igm aT [kg/m ³] (isolines)
-40
-30
-20
-10
0
Dep
th [m
]
- 9
- 8
- 7
- 6
- 5
- 4
- 3
55.09 55 .10 55.11 55.12 55.13 55 .14 55.15 55.16
C urrent velocity east [m /s] (contour) / S igm aT [kg /m ³] (iso lines)
-40
-30
-20
-10
0
Dep
th [m
]
-0 .30-0 .20-0 .12-0 .08-0 .040.000.040.080.120.200.300.400.500.600.70
Cross channel transect30.01.2006 07:50 - 10:49 UTC
Along channel transect30.01.2006 11:58 - 22:39 UTC
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
C urrent ve locity east [m /s] (contour) / S igm aT [kg/m ³] (iso lines)
-40
-30
-20
-10
0
Dep
th [m
]
Inflowing plume north of Kriegers Flak
Mohrholz et al., in prep.
Hydrography at Bornholmsgat
QUANTAS – ADP structure function approach
55 .24 55.26 55.28 55.30 55.32 55.34 55.36 55 .38 55.40 55.42
Salin ity [PS U ]
-60
-40
-20
0
Dep
th [m
]
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
55 .24 55.26 55.28 55.30 55.32 55.34 55.36 55 .38 55.40 55.42
La titude [degN ]
log E ps ilon [W /kg] (color) - S igm a-t [kg /m ³] (contou r)
-60
-40
-20
0
Dep
th [m
]
- 9
- 8
- 7
- 6
- 5
- 4
- 3
14 .0 14.2 14.4 14 .6 14.8 15.0
Longitude [deg E ]
55.2
55.3
55.4
55.5
Latit
ude
[deg
N]
Mohrholz et al., in prep.
Transverse structure in Bornholm Channel
Reissmann et al., 2007
Model derived monthly mean vertically integrated physically and numerically induced salinity mixing
Physical mixing Numerical mixing
Burchard et al., 2007; Burchard and Rennau, 2007; Rennau et al., in prep.
10.82 10.84 10.86 10.88 10.9 10.92 10.94 10.96 10.9855.295
55.3
55.305
55.31
55.315
55.32
55.325
55.33
Longitude [Degree East]
Latit
ude
[Deg
ree
Nor
th]
Scanfish Tracks with R/V Prof. A. Penck close to the western GBL in April 2006
-800 -600 -400 -200 0 200 400 600 80020
25
30
salin
ity p
su
-800 -600 -400 -200 0 200 400 60015
20
25
salin
ity p
suDistance from the western GBL [m]
-800 -600 -400 -200 0 200 400 60015
20
25
salin
ity p
su
depth: 8 m
depth: 4 m
depth: 4.4 m
4 Apr 19 UTC; Fr = 0.67
5 Apr 13 UTC, Fr = 1.2
5 Apr 14 UTC; Fr = 1.2
Signature of piles
Current
Salz
geha
ltTe
mpe
ratu
r
Mixing by bridge
Mixing at the piles of the Western Great Belt Bridge
2400 2600 2800 3000 3200 3400 3600 3800 4000 4200 440018
20
22
24
26
28
salin
ity p
su
40/06/07 Scanfish 0004 03
2400 2600 2800 3000 3200 3400 3600 3800 4000 4200 44003.4
3.6
3.8
4
4.2
4.4
Distance [m]
t090
C [d
eg C
]
40/06/07 Scanfish 0004 03
depth: 4.5 m
5 April 12 UTC; Fr = 1.2
Lass et al., submitted
CTD chain tows at Western Great Belt Bridge
Lass et al., submitted
upstream downstream
Basic parameterisation for friction due to structures in water
Additional production of turbulence:
Friction coefficient:
QuantAS-IOW-Publications• Burchard, H., H.U. Lass, V. Mohrholz, L. Umlauf, J. Sellschopp, V. Fiekas, K.
Bolding, and L. Arneborg, "Dynamics of medium-intensity dense water plumes in the Arkona Sea", Western Baltic Sea, Ocean Dynamics, 55, 391-402, 2005.
• Sellschopp, J., L. Arneborg, M. Knoll, V. Fiekas, F. Gerdes, H. Burchard, H. U. Lass, V. Mohrholz, L. Umlauf, "Direct observations of a medium-intensity inflow into the Baltic Sea", Cont. Shelf Res., 26, 2393-2414, 2006.
• Arneborg, L., V. Fiekas, L. Umlauf, and H. Burchard, "Gravity current dynamics and entrainment - a process study based on observations in the Arkona Sea", J. Phys. Oceanogr., 37, 2094-2113, 2007.
• Umlauf, L., L. Arneborg, H. Burchard, V. Fiekas, H.U. Lass, V. Mohrholz, and H. Prandke, The transverse structure of turbulence in a rotating gravity current, Geophys. Res. Lett., 34, L08601, doi:10.1029/2007GL029521, 2007.
• Mohrholz, V., H. Prandke and H. U. Lass, Estimation of TKE dissipation rates in dense bottom plumes using a Pulse Coherent Acoustic Doppler Profiler (PC-ADP) - Structure function approach, J. Mar. Sys., accepted for publication.
• Burchard, H., F. Janssen, K. Bolding, L. Umlauf, and H. Rennau, Model simulations of dense bottom currents in the Western Baltic Sea, Cont. Shelf Res., accepted for publication.
• Burchard, H., and H. Rennau, Comparative quantification of physically and numerically induced mixing in ocean models, Ocean Modelling, accepted for publication.
• Reissmann, J., H. Burchard, R. Feistel, E. Hagen, H.U. Lass, V. Mohrholz, G. Nausch, L. Umlauf, and G. Wieczorek, State-of-the-art review on vertical mixing in the Baltic Sea and consequences for eutrophication, Progr. Oceanogr., accepted for publication.
• Lass, H.U., V. Mohrholz, M. Knoll, and H. Prandke, "On the impact of a pile on a moving stratified flow", Cont. Shelf Res., submitted.
Conclusions:
The inflow dynamics of the Arkona Sea are far more complex than assumed before.
Specifically the role of Earth rotation for entrainment had been underestimated before.
Next steps:
Calibration of the friction parameterisation by means of the lab experiments,the RANS experiments and the Great Belt Bridge field observations.
Various numerical experiments without and with the parameterisation ofdifferent wind farm locations and abundances in the Arkona Sea.
Evaluation of the wind farm effects and general recommendations for futurewind farm locations.