Orographic Influence on Adriatic Vortex Generation

Branka Ivančan-Picek and Vesna Jurčec

Meteorological and Hydrological Service

Zagreb, Croatia

e-mail: picek@cirus.dhz.hr

ICAM/MAP2003, BRIG, 18 - 23 May 2003

ICAM/MAP2003, BRIG, 18 - 23 May 2003

Subject:

cyclonic vortex genesis in the wind field

Purpose:

is to link the Alpine mesoscale wind characteristics to the vortex appearance following an intensive local-scale convective process during MAP IOP5

Gomis et al. (1990)- Meteor.Atmos.Phys.Jurčec et al. (1996)-Meteorologische Zeitschrift Ivančan-Picek and Tutiš (1996)- TellusBrzović (1999)- Contr.Atmos.Phys.Ivančan-Picek et al. (2003) - Meteorologische Zeitschrift

ICAM/MAP2003, BRIG, 18 - 23 May 2003

Adriatic vortex and wind characteristics:

200 km

BURA

JUGO

ICAM/MAP2003, BRIG, 18 - 23 May 2003

Scale separation technique:

Maddox (1980);Gomis et al. (1990);Jurčec et al. (1996); Ivančan-Picek (1998);

F1 and F2 are for low-pass

filters used to define the bandpass (mesoscale)filter BR. F2 also defines the macroscale field.

ICAM/MAP2003, BRIG, 18 - 23 May 2003

Data: all available data in the Adriatic coast and islands in addition to ordinary synoptic data

ICAM/MAP2003, BRIG, 18 - 23 May 2003

ICAM/MAP2003, BRIG, 18 - 23 May 2003

ICAM/MAP2003, BRIG, 18 - 23 May 2003

Focus:On the identification of mesoscale vortices in the high-resolution ALADIN model wind field

MAP IOP5

ICAM/MAP2003, BRIG, 18 - 23 May 2003

IOP5, 4 Oct 00 +

ICAM/MAP2003, BRIG, 18 - 23 May 2003

IOP5, 4 Oct 00 +

ICAM/MAP2003, BRIG, 18 - 23 May 2003

Conclusions:

Orographic influence on vortex generation comes from the mountain effect on the wind field - particularly on intensity and duration of Adriaticlocal winds bura and jugo

The three main currents over Alpine region are responsible for vortex generation:large scale flow - over eastern and western side of the Alpsmesoscale cross-Alpine flow confined to valley transverse sections toward the Genoa bay