Federal Department of Home Affairs FDHAFederal Office of Meteorology and Climatology MeteoSwiss

Data mining in the joint D-PHASE and COPS archive

Mathias W. Rotach, Marco Arpagaus Manfred Dorninger, Christoph Hegg,

Andrea Montani, Roberto Ranzi, Volker Wulfmeyer

COPS WorkshopHohenheim, 27-29 January 2008

2 D-PHASE | COPS Workshop, 27-29 January 2008 Hohenheim , DMathias Rotach (matias.rotach [at] meteoswiss.ch)

Data mining

• Data mining is the application of statistical -mathematical methods on a data set with the goal of pattern recognition. Thereby in particular those methods will be applied, which have excellent asymptotic run times. Thus data mining is often applied in connection with large data sets.

Wikipedia

3 D-PHASE | COPS Workshop, 27-29 January 2008 Hohenheim , DMathias Rotach (matias.rotach [at] meteoswiss.ch)

What is available?

• 7 probabilistic and 23 high-resolution deterministic atmospheric models

• 7 coupled hydrological models (deterministic and probabilistic)

• Lots of model runs • Lots of data

4 D-PHASE | COPS Workshop, 27-29 January 2008 Hohenheim , DMathias Rotach (matias.rotach [at] meteoswiss.ch)

What is available?

• 6 months, 180 days, 4380 hours• > 10‘000 model runs (only atmospheric)• > 20‘000‘000 warnings• > 50‘000‘000 graphic files (only atmospheric)• > 50‘000‘000 model fields (COPS domain, JJA)

from high-resolution models

All stored at DA in Hamburg....and made possible through collaboration with COPS

5 D-PHASE | COPS Workshop, 27-29 January 2008 Hohenheim , DMathias Rotach (matias.rotach [at] meteoswiss.ch)

What can be done?

• Evaluate numerical models using COPS data--> find model deficiencies--> investigate key processes in orographic precipitation--> case studies

• Expect many examples

6 D-PHASE | COPS Workshop, 27-29 January 2008 Hohenheim , DMathias Rotach (matias.rotach [at] meteoswiss.ch)

What can be done?

• Evaluate numerical models in D-PHASE Domain• Example: COSMO-LEPS• SYNOP reports over the MAP D-PHASE (about 470

stations each day)• 12h-cumulated precipitation • Courtesy Chiara Marsigli and Andrea Montani,

ARPA-SIM

7 D-PHASE | COPS Workshop, 27-29 January 2008 Hohenheim , DMathias Rotach (matias.rotach [at] meteoswiss.ch)

COSMO-LEPS Verification

Brier Skill Score, JJA, D-PHASE domain, 12h, 10mm

2007

--> forecast range

--> B

SS

8 D-PHASE | COPS Workshop, 27-29 January 2008 Hohenheim , DMathias Rotach (matias.rotach [at] meteoswiss.ch)

COSMO-LEPS Verification

ROC area, JJA, D-PHASE domain, 12h, 10mm

--> forecast range

--> R

OC

are

a

9 D-PHASE | COPS Workshop, 27-29 January 2008 Hohenheim , DMathias Rotach (matias.rotach [at] meteoswiss.ch)

Ensemble System - biases

• COSMO-LEPS reforecasts• 30 yrs for each day

--> Correct for systematic model errors (spatial & temporal) --> Calibrate over the whole model domain --> Increase the skill (reliability) of the forecast --> Infer on extremity of the forecast

• Courtesy Felix Fundel, MeteoSwiss & NCCR Climate

10 D-PHASE | COPS Workshop, 27-29 January 2008 Hohenheim , DMathias Rotach (matias.rotach [at] meteoswiss.ch)

New warning index:Probability to exceed a Return Period, PRP

Approach:- Use the model climatology to find a return level for a certain return period (for each grid point)- Find number of forecasts exceeding the return level- Give a probability to exceed the return level/period (PRP)(- Use Extreme Value Aanalysis for very rare events (e.g. fit of a GPD))

Syntax:PRPx = Probab. to exceed an event occurring with a return period according to the x-quantile

Example:PRP0.8 = event occurs every 5th day

COSMO-LEPS reforecast

14 D-PHASE | COPS Workshop, 27-29 January 2008 Hohenheim , DMathias Rotach (matias.rotach [at] meteoswiss.ch)

Verification

Verification of the PRPx

Domain SwitzerlandVerification on CLEPS 10km x 10km gridPRPx from observations necessary

Compare uncalibrated to calibrated PRPx

• 24h total precipitation 1971-2000• >440 stations in Switzerland• interpolated on CLEPS grid• at least 3 Stations/grid point• search radius 2-4 grid points• distance weighting

Observation Climatology

15 D-PHASE | COPS Workshop, 27-29 January 2008 Hohenheim , DMathias Rotach (matias.rotach [at] meteoswiss.ch)

Verification

Relative improvement

16 D-PHASE | COPS Workshop, 27-29 January 2008 Hohenheim , DMathias Rotach (matias.rotach [at] meteoswiss.ch)

Verification

Relative improvement

17 D-PHASE | COPS Workshop, 27-29 January 2008 Hohenheim , DMathias Rotach (matias.rotach [at] meteoswiss.ch)

Verification

Relative improvement

18 D-PHASE | COPS Workshop, 27-29 January 2008 Hohenheim , DMathias Rotach (matias.rotach [at] meteoswiss.ch)

What can be done?

• Compare different high-resolution models• Example: Radar data composit over Switzerland• Summer (JJA) 2007• Courtesy Felix Ament, MeteoSwiss

19 D-PHASE | COPS Workshop, 27-29 January 2008 Hohenheim , DMathias Rotach (matias.rotach [at] meteoswiss.ch)

Verification of precipitation amountSwitzerland, summer (JJA)

Individual warning region, summer (JJA)

Individual warning region, 3h resolution, summer (JJA)

20 D-PHASE | COPS Workshop, 27-29 January 2008 Hohenheim , DMathias Rotach (matias.rotach [at] meteoswiss.ch)

Warngings – yellow level(yellow = frequency 10x per year)

Warning frequency 0.91

Probability to correctly warn (hit rate) 51%

False alarm ratio 45%

and

but

COSMO-2

21 D-PHASE | COPS Workshop, 27-29 January 2008 Hohenheim , DMathias Rotach (matias.rotach [at] meteoswiss.ch)

What can be done?

• Investigate properties of ensemble systems @ small scales

• Single model vs. multi model--> ‚micro PEPS‘ (Michael Denhard, DWD)

• Initial perturbations--> lagged ensembles--> physical perturbation--> spread-skill relations

• Predictability (convection)

22 D-PHASE | COPS Workshop, 27-29 January 2008 Hohenheim , DMathias Rotach (matias.rotach [at] meteoswiss.ch)

What can be done?

• All the hydrological components.....

Countesy S. Jaun ETHZ

23 D-PHASE | COPS Workshop, 27-29 January 2008 Hohenheim , DMathias Rotach (matias.rotach [at] meteoswiss.ch)

Summary

• Lots of possibilities Let‘s just do it!