Reinhold Steinacker ICAM-MAP-2003 1

Climatology of Mesoscale Alpine Phenomena

University of Vienna Department of Meteorology

and Geophysics

Reinhold Steinacker, Christoph LotteranerDepartment of Meteorology and Geophysics

University of Vienna, Austria

• Motivation• VERACLIM• Some selected results• Conclusion

Reinhold Steinacker ICAM-MAP-2003 2

University of Vienna Department of Meteorology

and Geophysics

• Motivation:

Much of the conventional climatological work (long term climatographies) so far have been using 1D (time series analysis) and/or large scale/meso alpha scale3D/4D (space-time analysis; reanalysis)

Mesoscale climatographies were mostly restrictedto national or regional boundaries

Some of intense climate phenomena (extreme events especially over complex terrain) are on meso beta or even meso gamma scale!

Reinhold Steinacker ICAM-MAP-2003 3

University of Vienna Department of Meteorology

and Geophysics

Example: 3 National Weather Services (AT,CH.SI)monthly precipitation

CH

AT

SI

Reinhold Steinacker ICAM-MAP-2003 4

University of Vienna Department of Meteorology

and Geophysics

Example:Berliner WetterkarteMonthly mean sea level pressureDecember 2001Source: Met. Inst. FU Berlin

Reinhold Steinacker ICAM-MAP-2003 5

University of Vienna Department of Meteorology

and Geophysics

Example: ERA40; December 2001Monthly mean sea level pressure 850 hPaSource: ECMWF; www.ecmwf

Reinhold Steinacker ICAM-MAP-2003 6

University of Vienna Department of Meteorology

and Geophysics

• VERACLIM

A project sponsored by the Austrian Science Foundationto create a mesoscale (meso beta; 20, 10 km horiz. res.) analysis of the Alpine Atmosphere for the last 30 years.Data: GTS-type, 3-hourlyMethod: Variational (spline), including downscaling and CQCPrimary variables: Theta, Theta-E, msl-pressure, sfc-windSecondary variables: precipitation, snow depth, cloud coverDerived variables: p-tendency, stream-lines, melting level, CCL,

(moisture-flux-) divergence, ...1 parameter: 30(yr)*365(d)*8(3-hr)~87.600 fields á 2.400/9600 GP→10**8/10**9 GP

Reinhold Steinacker ICAM-MAP-2003 7

University of Vienna Department of Meteorology

and Geophysics

Reinhold Steinacker ICAM-MAP-2003 8

University of Vienna Department of Meteorology

and Geophysics

Reinhold Steinacker ICAM-MAP-2003 9

University of Vienna Department of Meteorology

and Geophysics

Reinhold Steinacker ICAM-MAP-2003 10

University of Vienna Department of Meteorology

and Geophysics

Reinhold Steinacker ICAM-MAP-2003 11

University of Vienna Department of Meteorology

and Geophysics

Reinhold Steinacker ICAM-MAP-2003 12

University of Vienna Department of Meteorology

and Geophysics

Reinhold Steinacker ICAM-MAP-2003 13

University of Vienna Department of Meteorology

and Geophysics

Reinhold Steinacker ICAM-MAP-2003 14

University of Vienna Department of Meteorology

and Geophysics

Reinhold Steinacker ICAM-MAP-2003 15

University of Vienna Department of Meteorology

and Geophysics

Monatlicher Tagesgang des Luftdruckes nördlich, südlich und in den Alpen (bezogen auf ein Mittel von 1020 hPa)

1015

1016

1017

1018

1019

1020

1021

1022

1023

1 2 3 4 5 6 7 8 9 10 11 12 13

Monat

Lu

ftd

ruc

k [

hP

a]

GP(33-16) Süden GP(33-25) Zentralalpen GP(33-34) Norden

Reinhold Steinacker ICAM-MAP-2003 16

University of Vienna Department of Meteorology

and Geophysics

• Conclusion and outlook

Until a mesoscale reanalysis system (4D-VAR) becomes available on a scale, resolving the Alpine topography realistically, VERACLIM represents a good basis for establishing high resolution (concerning time and space) fields for climatological work

Besides gridded fields also quality controlled data (biases, gross errors) are being determined

Evaluation will concentrate upon short duration, mesoscale phenomena around the Alps

A „reanalysis“ will be carried out with the new 4D VERA system, which is in the pre-operational phase, including a multivariate approach

Reinhold Steinacker ICAM-MAP-2003 17

University of Vienna Department of Meteorology

and Geophysics

F I F N IT H E E N D N D E