page 1 storminess in northern italy, the adriatic sea and a comparison to some other eu areas...

Storminess in Northern Italy, the Adriatic

Sea and a comparison to some other EU

areas

Christoph Matulla

Central Institute for Meteorology and Geodynamics,

AustriaEnvironment Canada, Toronto, Canada

Hans von Storch

Institute for Coastal Research, GKSS Research Center, Germany and KlimaCampus Hamburg, Germany27 October 2008, CORILA meeting in Venice

1851 foundation of the Austrian weather service, since 1872 located at Hohe Warte 38, architect:

Johann Heinrich Freiherr von Ferstel

1873 foundation of the International Meteorological Organization (IMO) in Vienna -- precurser organization of the WMO

6% flood 0,25% tsunami6,25% earthquake

11% severe storm

4% tornado

3% hail

1% other storms

1% flash flood

2,5% winter damage, frost2% wildfire

6,5%

81%

7% 5,5%

1 % heat wave, drought

Overall losses:US$ 1,700bn*

Insured losses: US$ 400bn*

3% wildfire

29% tropical storm

6% winter storm, blizzard

1% other storms

1% flash flood

7% heat wave, drought2% winter damage, frost

23% flood

19% earthquake

<1% volcanic activity

5% severe storm

20%

44%

24%

12%

49% tropical storm

13% winter storm, blizzard

1% tsunami

1% hail

2% tornado

<1% landslide

*original values

Natural disasters 1980 - 2006 Percentage distribution worldwide

© 2007 NatCatSERVICE, Geo Risks Research, Munich ReTaken from a presentation given by Mr Berz in Innsbruck at a COST meeting (2008)

What is happening to extratropical storminess? Is it presently evolving outside its range of natural variability?

At first sight this question appears to be best answered by the help of wind statistics, but wind time series are almost always

• inhomogeneous

• too short

Storminess in Northern Italy, the Adriatic sea and a comparison with some other

areas

One example from Vienna

Pressure based proxies are one way to assess storminess

(WASA, 1998)

Air pressure readings are usually homogenous and extend far back in time (pressure measurements are the ‘flagship’ of the meteorological measuring program)

Storm-proxies may be:

Annual/seasonal percentiles of geostrophic wind derived from triangles of pressure readings (e.g., 95 or 99%iles); such percentiles of geostrophic wind and of “real” wind are linearly related.

frequency of events with geostrophic wind equal or larger than 25 m/s

frequency of 24 hourly local pressure change of 16 hPa in a year

frequency of pressure readings less than 980 hPa in a year

Hovmöller diagrams

Northern Italy and the

Adriatic Sea

What it is about

Data across southern Europe are retrieved from http://eca.knmi.nl/

21 year Gaussian filtered

normalized

Southern European data weredownloaded from the European Climate Assessment & Dataset homepage

Homöller diagrams of seasonal pressure readings @

Hvar

The same for the tendencies @Hvar

Percentiles of daily pressure readings taken @ Lugano

TENDENCIES

Percentiles of daily pressure observations

@ Gospic

Gospic‘s tendencies

What‘s up?

•There is remarkable variablity within the pressure readings and their tendencies on a decadal timescale or so.•The Hovmöller diagrams reveal not much change in strom proxies over the past century.•That doesn‘t mean that there is no change ahead. It simply says that presently we don‘t experience a change in the storm climate triggered by climate change.•Climate change is distinct in thermic parameters (continental temperatures, extention of sea ice, sea level, glacier retreat, etc.) but not conveyed in storminess right now.•Do we have to fear powerful changes? Regarding storminess it doesn‘t look like this.

What‘s out there in other areas? How does the Italian result match with

other regions in Europe?

Relevant publications99%iles of annual geostrophic wind speeds

for a series of station triangles in the North Sea regions and in the Baltic Sea region.

Alexandersson et al., 2002

Putting geo-wind stories across Europe together

OEKT-10, Wien

2008-03-13

What may happen in the future?

RCAO/ECHAM4 RCAO/HadAM3HA2 SzenarioIPCC 2007

Conclusion

1. Monitoring extra-tropical storminess may be based on air pressure proxies.

2. This allows assessments for 100 and more years, which is essential.

3. Decades long upward and downwards trends have been detected.

4. These trends are not sustained and have shown recent reversals in all considered regions.

5. Recent trends are not beyond the range of natural variations, as given by the historical past, but are more of intermittent character. Regional temperatures rose significantly at the same time.

6. In N Europe the present absence of a detectable signal is consistent with RCM simulations.

7. In C Europe a positive trend to average storminess is to be observed

8. The areas we looked on in Europe show no significant change in storminess there seems to be no significant tend.

N Europe storminess

Relevant publicationsSchmidt, H. and H. von Storch, 1993: German Bight storms analyzed. - Nature 365, 791

Alexandersson, H., T. Schmith, K. Iden and H. Tuomenvirta, 1998: Long-term trend variations of the storm climate over NW Europe. The Global Atmos. Oc. System 6, 97-120

WASA, 1998: Changing waves and storms in the Northeast Atlantic? - Bull. Amer. Met. Soc. 79, 741-760

Bärring, L. and H. von Storch, 2004: Northern European Storminess since about 1800. Geophys. Res. Letters 31, L20202, doi:10.1029/2004GL020441, 1-4

Rockel, B., and K. Woth, 2007: Future changes in near surface wind extremes over Europe from an ensemble of RCM simulations. Climate Change, 10.1007/s10584-006-9227-y

Matulla, C., W. Schöner, H. Alexandersson, H. von Storch, and X.L. Wang, 2007: European Storminess: Late 19th Century to Present, Climate Dynamics DOI 10.1007/s00382-007-0333-y

The BACC author team, 2008: Assessment of Climate Change in the Baltic Sea Basin, Springer Verlag Berlin - Heidelberg; ISBN 978-3-540-72785, 473 pp

von Storch, H., and R. Weisse, 2008: Regional storm climate and related marine hazards in the Northeast Atlantic, In Diaz, H.F. and Murnane, R.J. (eds.), Climate Extremes and Society, Cambridge: Cambridge University Press (in press)

Matulla, C., and H. von Storch, 2008: Changes in Eastern Canadian Storminess since 1880. under revision

OEKT-10, Wien

2008-03-13

Shall we pay more money to insurance companies?

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