JOANNEUM RESEARCH Folien

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JOANNEUM RESEARCH Institute of Applied Systems
Technology (IAS) (Director Prof. Otto
Koudelka) Graz / Austria Precipitation Ground
Validation in Austria M. Schönhuber e-mail
Michael.Schoenhuber_at_joanneum.at phone 43 316
876 2512 fax [phone] - 92512 IAS
Radar and Propagation Research Group Head Prof.
W.L. Randeu K. Köck, E. Kubista, G. Lammer, T.
Prechtl, E.M. Richter, M. Schönhuber, N.
Witternigg Close cooperation with Radar and
Propagation Research Group IBK / TU Graz /
Austria
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IAS Contribution to GPM Ground Validation

• CONTENTS
• Motivation
• IAS Expertise
• Proposed IAS actions for GPM GV
• Summary and Conclusion

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Motivation

• Why an Austrian contribution to GPM GV
• geographical situation of Austria rises specific
  questions to GPM analyses
• special orographic conditions
• Austria faces precipitation related phenomena
  like floods and droughts

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Motivation Austrias geographical
situationhigh precipitation totals in the
Alpine mountain regions
Annual Precipitation in Europe Austria, mainly
located in the Alpine mountain region, faces high
precipitation totals, which elsewhere in Europe
are reached by the western coastal areas only.
Solid and mixed phase precipitation events are
frequent.
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Motivation mountaineous terrain, half Atlantic
and half continentally oriented ( high storm
probability at the southern rim of the Alps)
Mountaineous terrain in Austria map section of
valley Salzach, not far from the city of
Salzburg. Height profile leads to questions
arising when interpreting satellite data.
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Motivation Geographical situation of Austria
rises specific questions to GPM analyses

• Important specific aspects for GPM analyses
• considerable part of precipitation reaches ground
  in solid or melting state
• steep mountain height profiles cause even nadir
  looking instruments to observe non-uniformly
  filled beams (partly clutter, partly
  precipitation).
• specific climate type in Europe

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Some precipitation related phenomena in
AustriaAustrian winter skiing resorts and
avalanches
Skiing in Austria competition at the traditional
JOANNEUM RESEARCH skiing trip, March 2005
Avalanches the Austrian Armed Forces assisting
rescue work
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Some precipitation related phenomena in
AustriaFloods and droughts

Flood of August 21, 2005, in Graz / Andritz
Crop damage during drought and heat in 2003 in
Graz / Austria 40 tropic days ( gt 30 deg
C) instead of 4 usual ones
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IAS relevant experience (1)
IAS expertise in atmospheric observations and
research - Atmospheric observations and analyses
of precipitation phenomena Based on data of
ground based instruments (Radar, Lidar, Radar
Network, disdrometers, ...) IAS has wide
experience in observing and analysing
precipitation phenomena. This includes
statistical analyses for communication purposes
(e.g. worst month considerations, site diversity
statistics, ...), statistics on cloud layers
derived from Lidar data, as well studies on
precipitation microstructure comparing imaging
2D-Video-Distrometer with polarimetric radar
data. - Recent focus on mixed phase and solid
precipitation events IAS in cooperation with TU
Graz recently carried out investigations on
particle characteristics and wave propagation in
mixed phase and solid precipitation in more
detail, including calculations of scattering
amplitudes for snowflake models derived from
2D-Video-Distrometer data.
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IAS relevant experience (2)
IAS expertise in atmospheric observations and
research - Flood related issues e.g. within
the EU Project MEFFE (FP4), contributing to
comparisons with space borne data - Hardware
development and system maintenance IAS has a long
tradition of developing, manufacturing and
operating instruments and systems for
tropospheric observations, via cooperation with
TU Graz also in weather radar networking. IAS is
the supplier of the 2D-Video-Distrometer, which
originally was developed to meet own needs.
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IAS expertise modelling work for propagation,
navigation and hydrological purposes.
Rain event recorded by Austrian weather radar
network in August 21, 2005, when severe floods
occurred (Courtesy Austro Control GmbH,
Vienna).
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IAS expertise modelling work for propagation,
navigation and hydrological purposes.
Analysis of radar reflectivities and propagation
parameters along slantpath. Melting layer model
integrated
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IAS expertise flood related issues, e.g. within
project MEFFE (EU FP4)
3D representation of storm event, as recorded by
dual pol. C-band research weather radar Graz /
Hilmwarte, for verification of space borne data
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IAS expertise data acquisition for atmospheric
studies
Part of scenario proposed for acquisition of
ground validation data
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IAS expertise mixed phase scattering studies
Investigations on mixed phase and solid
precipitation. Award winning conference
contribution in this field (best poster paper on
propagation, AP2000, Davos / Switzerland). Ongoing
analyses of calculation of precipitation
particles scttering for ice and snow, first tests
of algorithms for nonrevolution particles.
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IAS expertise, in cooperation with TU
GrazModelling a 3D particle from 2DVD snowflake
data
front and side view of a snowflake, as recorded
by the imaging 2D-Video-Distrometer (2DVD)
modelling a 3D particle from snowflake data,
volume cut out from spheroid is 78 mm3
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IAS expertise, in cooperation with TU Grazradar
cross section results for snowflake model
Scattering direction given by ? and ?. Incidence
along x-axis (from neg. to pos. x-values!)
vertical polarisation
RCS plot for 78 GHz, based on preconditions shown
in above figures
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Proposed IAS actions for GPM Ground
Validationcollection of a data base
Collection of a data base for atmospheric
studies, with focus on Austria, especially on
Styria and the city of Graz including for a
period of three years (at least) the Austrian
Weather Radar network (4 C-band radars)
raingauge network, focus on the federal state of
Styria 2D-Video-Distrometer (2DVD) in Graz /
Austria a Lidar in Graz / Austria auxiliary
data potentially a research radar in Graz /
Austria (depending on availability) a second
2DVD at Mt. Schöckel, some 1000 meters above
Graz, in 12 km distance only
REALIZATION OF PLANS DEPENDS ON AVAILABILITY OF
PROJECT FUNDING
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Proposed IAS actions for GPM Ground
ValidationData analysis and modelling work (1)

• Prediction of space borne observables (1)
• Ground validation data shall be analysed to
  predict the reflectivities of a space borne
  precipitation radar, also considering issues of
  passive space borne measurements. These analyses
  would include discussions of the following
  questions, some of them already partly answered
  in relevant literature
• individual particles what is the typical shape
  of raindrops, snow- flakes, hailstones.
  Scattering amplitudes for raindrops are well
  known, how could a reliable model for solid
  precip. particles look like.
• microstructure what are typical size
  distributions in rain, snow and hail events.
  What are the characteristics of the melting layer
  in terms of thickness, size distributions,
  fall velocities, etc.

REALIZATION OF PLANS DEPENDS ON AVAILABILITY OF
PROJECT FUNDING
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Proposed IAS actions for GPM Ground
ValidationData analysis and modelling work (2)
Prediction of space borne observables
(2) height profile of the precipitation
events what are the individual portions
(rain, melting, ice), how is the satellite signal
affected cloud properties obtain cloud base
height and cloud optical thickness,
investigate particle characteristics during
drizzle, snow and mixed phase geographical
considerations how is the interference of rain
and clutter echos in mountaineous
terrain. spatial distribution of rain what are
typical cell sizes, does the integration over
antenna footprint size distort the results ?
REALIZATION OF PLANS DEPENDS ON AVAILABILITY OF
PROJECT FUNDING
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Proposed IAS actions for GPM Ground
ValidationComparisons of predicted and measured
spaceborne data
Comparisons of predicted and measured spaceborne
data IAS will seek cooperation with
institutions analysing space borne GPM data
and then carry out comparisons between ground
based predictions and directly measured
precipitation. Such comparisons are the only
way to answer open questions of space borne
data products, improve and enhance precipitation
models, explain system insufficiencies, ...
REALIZATION OF PLANS DEPENDS ON AVAILABILITY OF
PROJECT FUNDING
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Summary and Conclusion
GPM and Austrian ground validation work will
result in mutual benefits for local interests and
for the worldwide GPM community analysing
global data the specific local situation
(geographic and climatic circumstances) may
better be considered and explained with high
quality ground validation data
available detailed analysis of local situations
leads to improved atmospheric modelling with
wider validity enhanced understanding of
precipitation processes may help for improved
answers to local requirements, like mitigating
the threats by floods, droughts, avalanches, or
like securing future fresh water supply and many
others more.