The second mesoscale experiment in the Pomo pits (Middle Adriatic Sea, May-June 1993)

Aniello RUSSO, Antonio ARTEGIANI, Mauro GALASSI, Mauro MARINI, Elio PASCHINI

C.N.R. - Istituto di Ricerche sulla PEsca Marittima (IRPEM)L.go Fiera della Pesca, 60125 Ancona, ITALY Web: http://adria.irpem.an.cnr.it

N. PINARDI, M. ZAVATARELLIC.N.R. - Istituto per le Metodologie Geofisiche Ambientali, Bologna, Italy

F. RAICICH C.N.R. - Istituto Talassografico Sperimentale, Trieste, Italy

A. R. ROBINSON, C. J. LOZANO Department of Earth and Planetary Sciences, Harvard University, Cambridge, USA

The second mesoscale experiment in the Pomo pits

(Middle Adriatic Sea, May-June 1993)

12° E 13° E 14° E 15° E 16° E 17° E 18° E 19° E39° N

40° N

41° N

42° N

43° N

44° N

45° N

46° N

20

40

60

80

200

P o

A n c o n a

V i e s t e

S p l i t

160

1000200

IONIAN SEA

Otranto

Pescara

Sibenik

Bari

Dubrovnik100

800

Pelagosa sill

Otranto sill

Pomo Pits

Mappa Adriatico

Schematic of the Adriatic Sea General Circulation(from Artegiani et al., 1997)

Position of the stations for the two experiments

101103

105107

109111

113115

117

119

121

201203

205

207101

211213

215

217

219221

301

303305

307309

311313

315317

319321

401403

405

407409

411413

415

417419

421

501503

505

507509

511513

515517

519521

601

603605

607

609611

613615

617

619621

701703

705707

709711

713715

717719

721

AM EX2-A station positions

14° 10' E 15° 00' E42° 10' N

43° 00' N

20 40 60 80100

120

120

140

140160

160

180

200

200 140

101

103105

107109

111113

115117

119

121

201203

205207

209211

213215

217219

221

301

303305

307309

313315

317

319

321

401403

405

407409

411413

415

417419

421

501503

505507

509511

513515

517

519521

601

603605

607

609611

613

615617

619

621

701703

705707

709711

713

715717

719721

801803

805807

809811

813815

817819

821

AM EX2-B station positions

14° 10' E 15° 00' E42° 10' N

43° 00' N

20 40 60 80100

120

120

140

140160

160

180

200

200 140

9-11 May 1993 6-9 June 1993

Position of the stations for the two experiments. The maps are rotated and converted to a cartesian reference system.

-40 -20 0 20 40k m

A M E X 2 - 1 S t a t i o n p o s i t i o n s

-40

-20

0

20

40

km

2 0 0

1 00

-40 -20 0 20 40k m

A M E X 2 - 2 S t a t i o n p o s i t i o n s

-40

-20

0

20

40

2 0 0

1 0 0

9-11 May 199375 CTD casts

6-9 June 199382 CTD casts

+ CTD cast Chem ical cast

Cumulative vertical profiles

1 0 1 5 2 0 2 5Tem perature (°C )

0

50

100

150

200

250

300

pres

sure

(db

)

0

50

100

150

200

250

300

35 36 37 38 39Salin ity (psu)

AMEX2-B June 1993

AMEX2-A May 1993

Dep

th (

m)

% sat. O2 Nitrate (µM) Silicate (µM)

Vertical profiles in the Western Pomo Pit in the 1993-96 period

After a bottom water renewal, in the bottom layer density(not showed) and % of dissolved oxygen saturation decrease while temperature (not showed) and nutrient salts concentration increase

Bottom maps

AM EX2-A bottom tem perature

20 40 60 80100

120

120

140

140160

160

180

200

200 140

10.210.310.410.510.610.710.810.911.011.111.211.311.411.511.611.711.811.9

AM EX2-B bottom d isso lved oxygen

20 40 60 80100

120

120

140

140160

160

180

200

200 140

5.005.055.105.155.205.255.305.355.405.455.505.555.605.655.705.755.805.855.905.956.00

AM EX2-B bottom tem perature

20 40 60 80100

120

120

140

140160

160

180

200

200 140

10.210.310.410.510.610.710.810.911.011.111.211.311.411.511.611.711.811.9

AM EX2-B bottom sa lin ity

20 40 60 80100

120

120

140

140160

160

180

200

200 140

38.2038.2238.2438.2638.2838.3038.3238.3438.3638.3838.4038.4238.4438.4638.4838.50

AM EX2-A bottom sa lin ity

20 40 60 80100

120

120

140

140160

160

180

200

200 140

38.2038.2238.2438.2638.2838.3038.3238.3438.3638.3838.4038.4238.4438.4638.4838.50 AM EX2-A bottom d isso lved oxygen (m l/l)

20 40 60 80100

120

120

140

140160

160

180

200

200 140

5.005.055.105.155.205.255.305.355.405.455.505.555.605.655.705.755.805.855.905.956.00

SW-NE cross-section (May 1993)

SW-NE cross-section (June 1993)

OAG AMEX2-2

Bathy model

Global OA parametersZonal and meridional zero crossing of the correlation: 40 kmZonal decorrelation (decay) scale: 20 kmTime decorrelation: 7 daysPE model domainGrid: 39*39*20 levels 2 km horizontal resolution, 5 flat level and 15 sigma levels

11 May 1993 7 June 1993

Base

Base + ext. Forcing

Assimilation

Base B

Base + ext. Forcing B

Simulations table

Base C4 10 day

Base C4 11 day

Base C4 12 day

Base C4 13 day

Base C4 14 day

Base C4 15 day

Base May Baro 4 days

Base June Baro 4 days

Frc June Baro 4 days

Base June Salinity and velocity 40m

Frc June Salinity and velocity 40m

Wind AMEX

-8

-6

-4

-2

0

2

4

6

8

-8 -6 -4 -2 0 2 4 6 8

may93

june93ECMWF wind in the AMEX domain.

The average intensity in June 1993 (3.4 m/s) was about 20% greater than in May 1993 (2.8 m/s).

- Nesting in an Adriatic model to improve boundary conditions

- Refinements of meteo forcing (ECMWF reanalyzes, offshore

platforms)

- Real time regional forecast experiment

- Ecosystem studies.

- Barotropic velocities dominate the Pits area in spring, with currents forming filaments about 10 km wide- Baroclinic field determines the coastal currents, with an evident 5 days oscillation- Wind forcing do not affect the May 1993 simulation, while it is able to reverse the June circulation in the Pits

Main remarks from the first simulations

Future Perspectives

AMEX1 Sep. 1989 Profili verticali modi baroclini

From Paschini et al., D.S.R.1993

Profili verticali modi baroclini

Baroclinic vertical modes

Squared Brunt-Vaisala frequency(N2)

First internal Rossby radius:AMEX Sept. 1989: 5.4 kmAMEX2-A May 1993: 3.5 - 4.0 kmAMEX2-B June 1993: 4.5 - 5.0 km

Profili verticali modi baroclini

Brunt-Vaisala

0.00E+00

1.00E-03

2.00E-03

3.00E-03

0 50 100

150

200

250

413B BVF 413A BVF

Alongshore cross-section in the Western Pomo Pit (May 1993)

0 20 40 60 80 100 120 140 160km

-250

-200

-150

-100

-50

0

m

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-200

-150

-100

-50

0

m

W IN TER

0 20 40 60 80 100 120 140 160km

Tem perature (°C ) a long the Pescara-S ibenik section (c.i. 0.5)

SPRIN G

SUM M ER AUTUM N6.07.08.09.010.011.012.013.014.015.016.017.018.019.020.021.022.023.024.025.026.027.0

Temperature at Pescara section