evaluation of satellite-derived high resolution...
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EVALUATION OF SATELLITEEVALUATION OF SATELLITE--DERIVED HIGH DERIVED HIGH RESOLUTION RAINFALL ESTIMATES OVER RESOLUTION RAINFALL ESTIMATES OVER
EASTERN SÃO PAULO AND PARANEASTERN SÃO PAULO AND PARANÁÁ, BRAZIL, BRAZIL
Augusto J. Pereira FilhoAugusto J. Pereira Filho11
Phillip Phillip ArkinArkin 22
Joe TurkJoe Turk33
John E. JanowiakJohn E. Janowiak44
Cesar BenetiCesar Beneti55
Leonardo Leonardo CalvettiCalvetti 55
Ricardo HallakRicardo Hallak11
Felipe VemadoFelipe Vemado11
1DAC/IAG, University of São Paulo, Brazil2ESSIC, University of Maryland, College Park, USA
3NRL, Marine Meteorology Division, USA4Climate Prediction Center/NOAA, USA
5SIMEPAR, Paraná, Brazil
PEHRPP PEHRPP WokshopWokshop, , GeneveGeneve, Switzerland, Switzerland0303--05 December, 200705 December, 2007
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São PauloSão Paulo
ParanParanáá
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Background
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HOURLY ACCUMULATION2003 and 2004
(mm)(Pereira Filho et al., 2006)(Pereira Filho et al., 2006)
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TIME OF MAXIMUM RAINFALL
(mm)
(UTC)
2003 and 2004
(Pereira Filho et al., 2006)(Pereira Filho et al., 2006)
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33rdrd INTERNATIONAL PRECIPITATION WORKING GROUP WORKSHOPINTERNATIONAL PRECIPITATION WORKING GROUP WORKSHOP2323--27 October 2006, Melbourne, Australia27 October 2006, Melbourne, Australia
RADAR X SATELLITE
Total Rainfall
1 = Ground Clutter Filtering (2 and 3)4 = Grind Clutter Contamination5 = Range Effect7 = Signal Processing
(Pereira Filho et al., 2002)(Pereira Filho et al., 2002)
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Program for the Evaluation of High Resolution Precipitation Products (PEHRPP) coordinated by ESSIC and NRL.
Goal is to compare and to validate these high resolution datasets.
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Estimated Observed
Falsealarms
Hits
MissesObserved
yes no
yes hits false alarms
no misses correct negativesE
stim
ated
Contingency Table
(Elbert, 2003)(Elbert, 2003)
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False alarm ratioalarmsfalsehits
alarmsfalseFAR
+
=
Probability of detectionmisseshits
hitsPOD+
=
Critical success indexalarmsfalsemisseshits
hitsCSI ++
=
misseshitsalarmsfalsehitsBIAS
++
= Bias score
Correlation coefficient∑∑
∑−−
−−=
22 )()(
)( )(
OOEE
OOEEρ
Root mean square error 2
1
)(1i
N
ii OE
NRMSE −= ∑
=
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SPWR RAINFALL ESTIMATES
X
CMORPH, TRMM, PERSIANN and NRL- BLENDED
(m)
São Paulo, Brazil.
Workshop on the EHRPPWorkshop on the EHRPPGeneve, Switzerland , 03Geneve, Switzerland , 03--05 December, 200705 December, 2007
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SPWR DATASETS: 10/2005 TO 03/2006;
SATELLITE PRECIPITATION DATA:
0.25 DEGREE X 3-HOUR;
SYSTEM TYPES:
COLD FRONT, RAIN BANDS, ORDINARY COLD FRONT, RAIN BANDS, ORDINARY CONVECTIONCONVECTION, SQUALL LINES
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EXAMPLES
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COLD FRONTCOLD FRONT
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RAIN BANDSRAIN BANDS
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33rdrd INTERNATIONAL PRECIPITATION WORKING GROUP WORKSHOPINTERNATIONAL PRECIPITATION WORKING GROUP WORKSHOP2323--27 October 2006, Melbourne, Australia27 October 2006, Melbourne, Australia
OR
DIN
AR
Y C
ON
VE
CTIO
NO
RD
INA
RY
CO
NV
EC
TION
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0,05
0,1
0,15
0,2
TRMM CMORPH PERSIANN NRL-B
Mea
n C
SI0,1 mm
0,2 mm
1,0 mm
4,0 mm
OVERALL RESULTS
All data sets available 10/05 to 03/06
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DISCUSSION (SP)•• Coordinate discrepancies;Coordinate discrepancies;•• Phase and amplitude errors;Phase and amplitude errors;•• All four methods yielded poor results;All four methods yielded poor results;•• Radar rainfall accumulation higher than satellite ones; Radar rainfall accumulation higher than satellite ones; •• Radar data with range effect and other problems;Radar data with range effect and other problems;•• Best performance for low rainfall accumulation: CMORPH; Best performance for low rainfall accumulation: CMORPH; •• Best performance for higher accumulation: PERSIANN;Best performance for higher accumulation: PERSIANN;•• Fewer data for PERSIANN;Fewer data for PERSIANN;•• All methods are limited;All methods are limited;•• Need for rain gauges and stream gauges verification.Need for rain gauges and stream gauges verification.
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PARANA STATESatellite techniques: CMORPH (Joyce et. al., 2004), PERSIANN (Sorooshian et al., 2000), TRMM (Huffman et. al., 1997), NRLB (Turk et. al., 2003) and CST (Adler e Negri, 1998).
Data
141 weather stations over Parana State
Methodology
1) Observed and estimated rainfall @ 0.25° spatial resolution over 56°W – 46.75°W and 27°S-21.75°S for 1 day to a month accumulation.
2)Period: January 2003 – December 2005
3)Rain/non-rain threshold: 0.3mm/day and 20mm/month;
4)Statistics: average, variance, bias, POD FAR, ETS, MSE, correlation coefficient;
5)Hovmoller diagrams.
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Hovmöller Diagrams
GAUGE CMORPH TRMM
PERSIANN NRLB CSTmm/month mm/month mm/month
mm/month mm/month mm/month
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Monthly AccumulationOctober 2005
May 2005
BIAS 0.99 1.00 POD 0.99 1.00FAR 0.00 0.00COR 0.67 0.62RMSE 130.40 79.86GAUGE AVE 245.42 245.42SAT AVE 123.80 182.25 GAUGE VAR 59.71 59.71SAT VAR 54.88 50.48
NRLB CST
GAUGE
GAUGE
NRLB CST
TRMM
mm/month mm/month mm/month
mm/month mm/month
BIAS 0.95 POD 0.95FAR 0.00COR 0.79RMSE 104.02GAUGE AVE 136.22SAT AVE 52.98GAUGE VAR 74.39SAT VAR 23.85
TRMM
CST ra in n o n -ra in
ra in 5 5 2 0n o n -ra in 0 0
NRLB ra in non -ra in
ra in 546 0non -ra in 1 0
TRMM ra in non -ra in
ra in 522 0non -ra in 28 0
Observed
ObservedObserved
Estimated
Estimated Estimated
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Monthly Accumulations - Spatial BIAS(Jan/2003 - Dec/2005)
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Daily Accumulation
November 17th, 2003
May 12th, 2004
BIAS 1.05 POD 0.99
FAR 0.05 COR 0.64 RMSE 20.40 GAUGE AVE 32.05 SAT AVE 16.43 GAUGE VAR 17.41 SAT VAR 8.59
BIAS 0.99 POD 0.96 FAR 0.03 COR 0.75 RMSE 14.88 GAUGE AVE 25.76 SAT AVE 18.93 GAUGE VAR 19.30 SAT VAR 17.12
CMORPH
TRMM
CMORPH ra in no n -ra in
ra in 5 18 29n on -ra in 3 0
TRMM ra in n on -ra in
ra in 4 24 1 3n on -ra in 1 9 8 4
Observed
Estimated
Observed
Estimated
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Discussion (PR)Hovmöller diagrams indicate good agreement between satellite-derived estimates and gauges, though amplitude differences are significant.
Monthly satellite-derived accumulations better for January, May and October. Daily values highly variable.
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Polarimetric Data Sets
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Mobile Weather Radar Doppler Dual X-band (MXPOL) Hydrometeorology Lab (LabHidro) – Institute of Astronomy, Geophysics and Atmospheric Sciences (IAG), University of São Paulo .
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MXPOL 4,5o PPI at 2119 UTC on 26 April 2007.
Zh Vr W
Kdpρohv
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SPWR 3-km CAPPI 1-km x 1-km resolution at 1616 UTC on 22 May 2007. MXPOL at (23o33.4’S; 46o44.1’W).
São Paulo City sounding (83779) at 1200 UTC on 22 May 2007.
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MXPOL vertical profiles at 1616 UTC on 22 May 2007. Full clockwise antenna scan (6.0o s-1) @ 90o, pulse width = 0.2 μs, PRF=1000 Hz and 256 samples, Δz=35m.
Vertical profile - Zh
Vertical profile - W
Vertical profile - Vr
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MXPOL vertical profiles at 1616 UTC on 22 May 2007. Full clockwise antenna scan (6.0o s-1) @ 90o, pulse width = 0.2 μs, PRF=1000 Hz and 256 samples, Δz=35m.
Vertical profile - Kdp
Vertical profile - Zdr
Vertical profile - ρohv
Vertical profile - φdp
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THE END
Work supported by:Work supported by:FAPESP and CNPq (BRAZIL) FAPESP and CNPq (BRAZIL) NCAR and ESSIC (USA)NCAR and ESSIC (USA)WMOWMO
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