Quantitative evaluation of regional precipitation

forecasts for Belgium using multi-dimensional

remote sensing observations (QUEST-B)

Nicole van Lipziga, Laurent deLobbeb, Susanne Crewellc

a Physical and regional geography group, K.U.Leuven, Belgiumb Royal Meteorological Institute of Belgium (RMI)

c Meteorologisches Institut, Universität Köln

Kwinten Van Weverberg (PhD project)Ingo Meirold-Mautner (PostDoc project)

LE

satellite

MSG ~ 5km; 15min Cloud Mask Cloud top pressureMODIS ~ 1km; 1day Cloud Mask Optical thickness

IPT / Micro-wave 1D vertical; Lindenberg (and Cabauw) temperature profile humidity profile LWC

GPS

147 stations; Germany; 30min IWV

Ceilometer

17 stations;Germany; 1min; ranges up to 4km Cloud base height Cloud cover (<4km)

Radar

DX radar composite; 1km; 5min Rain ratePolarimetric radar (DLR)

Multi-dimensional remote sensing

Radar of Wideumont

• C-band Doppler Radar Gematronik

• Tower : 46 m

• Antenna height : 592 m

• Antenna diameter : 4.2 m

• Measurements range:

240 km for reflectivity 120 km for velocity

Radar of Zaventem (Brussels)

• C-band Doppler Radar Radtec/Sigmet

• On the top of Brucargo . . .. building

• Antenna diameter : 4.2 m

• Measurements range:

250 km for reflectivity 120 km for velocity

LMK domain

Atmospheric models:

•Lokal-Modell: LMK (LMKürzestfrist) (Δx=2.8 km)

•Aladin (Δx=7 km; Δx=4 km) used for operational weather forecasting in Belgium: based on French AROME modeling system

•Advanced Regional Prediction System: ARPS (Δx=3 km)

Phase I: Model evaluation

Phase II: Compilation of precipitation distribution for two contrasting summer

seasons

•Improve understanding of causes for these differences in precipitation characteristics

•Input for soil erosion models and crop models

Soil erosion in Flanders(Belgium)(Verstraeten et al. 2003)

Orography of Belgium

y = 0.1089x1.8067

R2 = 0.82n = 11780

0.01

0.1

1

10

100

1000

1 10 100

P (mm) for every rain event

rain

ero

sivi

ty f

or

ea

ch r

ain

eve

nt

Amount of precipitation is important for soil erosion

P (mm) per rain event

Rai

n e

rosi

vity

fo

r a

rain

eve

nt

Timeseries forthe Belgian

station Ukkel

Verstraeten and Poesen, 2006

Sensitivity of the precipitation distribution for climatic changes

•Temperature forcing at the lateral boundaries of the model domain (surrogate climate scenarios)

•Effect of changes in atmospheric circulation (classification into weather types)

Summary

•Evaluation of QPF for Belgium using different atmospheric modeling systems

•Identify weaknesses and strengths of the different modeling systems (for regions, weather types, precipitation regimes …)

•Insight in precipitation changes on a small scale for climatic changes

•Interaction between different disciplines (meteorology, geography, agriculture) with respect to atmospheric branch of hydrological cycle