Ensemble-Based Data Assimilation of GPM/DPR Reflectivity ...2. DA Experiments with NICAM-LETKF...
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2. DA Experiments with NICAM-LETKF Ensemble-Based Data Assimilation of GPM/DPR Reflectivity into the Nonhydrostatic Icosahedral Atmospheric Model NICAM Kotsuki, S. ([email protected]), K. Terasaki, and T. Miyoshi RIKEN Center for Computational Science, Japan NICAM-LETKF and GPM/DPR Level 2 Normal Scan (NS) Matched Scan (MS) High-Sensitivity (HS) width 245 km 125 km 125 km Δx 5 km 5 km 5km Δz 250 m 250 m 500 m Band Ku Ka Ka 3D reflectivity GPM/DPR core satellite (Hou et al. 2014) NICAM-LETKF (Terasaki et al. 2015) 3. Model Parameter Sensitivity to GPM/DPR First DA step column max reflectivity for KuPR DA cycle experiment Improved by GPM/DPR Degraded by GPM/DPR T Q RMSD vs. ERA Interim (2014) Not successful maybe due to ・ model imperfections ・ model bias ・ too sparse observation May be useful for parameter DA Parameter sensitivity investigated Single moment cloud microphysics (6-class) 1/2 ,, 0 ,, ,, ( ) / drsg trsg rsg v D c D 1/2 0 4 3 g g D g c C NICAM 6-class single moment scheme (NSW6; Tomita 2008) terminal velocity (m/s) 〇 Numerical Model: ・NICAM (Satoh et al. 2008, 2014) - 28-km resolution - single moment bulk could microphysics 〇 Data Assimilation: ・LETKF (Hunt et al. 2007) with 40 members ・RTPS (α=0.95) 〇 Observations: ・NCEP-PREPBUFR ・AMSU-A Radiances ・GSMaP w/ Gaussian Transform. (Kotsuki et al. 2017) ・Dual-frequency Precipi. Radar (DPR) CD (graupel) Cr (rain) NICAM default Sensitivity EXP (21 runs) min max resolution Cr 130.0 50 230 8 C D 0.60 0.20 1.00 0.04 ρ: density (kg/m 3 ) D: diameter (m) vertical profile of KuPR & KaPR weakly correlated weakly correlated Correlation b/w parameter & DPR
Transcript of Ensemble-Based Data Assimilation of GPM/DPR Reflectivity ...2. DA Experiments with NICAM-LETKF...
2. DA Experiments with NICAM-LETKF
Ensemble-Based Data Assimilation of GPM/DPR Reflectivity into the Nonhydrostatic Icosahedral Atmospheric Model NICAM
Kotsuki, S. ([email protected]), K. Terasaki, and T. MiyoshiRIKEN Center for Computational Science, Japan
NICAM-LETKF and GPM/DPR
Level 2 Normal Scan (NS)
Matched Scan (MS)
High-Sensitivity(HS)
width 245 km 125 km 125 kmΔx 5 km 5 km 5kmΔz 250 m 250 m 500 m
Band Ku Ka Ka
3D reflectivityGPM/DPR core satellite (Hou et al. 2014)
NICAM-LETKF (Terasaki et al. 2015)
3. Model Parameter Sensitivity to GPM/DPR
First DA step column max reflectivity for KuPR
DA cycle experiment
Improved by GPM/DPR Degraded by GPM/DPR
T Q
RMSD vs. ERA Interim (2014)
Not successful maybe due to・ model imperfections・ model bias・ too sparse observation
May be useful for parameter DA Parameter sensitivity investigated
Single moment cloud microphysics (6-class)
1/2, ,
0, , , ,( ) /d r s gt r s g r s gv D c D
1/2
0
4
3g
gD
gc
C
NICAM 6-class single moment scheme (NSW6; Tomita 2008)
terminal velocity (m/s)
〇 Numerical Model:・NICAM (Satoh et al. 2008, 2014)
- 28-km resolution- single moment bulk could microphysics
〇 Data Assimilation:・LETKF (Hunt et al. 2007) with 40 members・RTPS (α=0.95)〇 Observations:・NCEP-PREPBUFR・AMSU-A Radiances・GSMaP w/ Gaussian Transform. (Kotsuki et al. 2017)・Dual-frequency Precipi. Radar (DPR)
CD(graupel)
Cr(rain)
NICAM default Sensitivity EXP (21 runs)
min max resolution
Cr 130.0 50 230 8
CD 0.60 0.20 1.00 0.04
ρ: density (kg/m3)D: diameter (m)
vertical profile of KuPR & KaPR
weaklycorrelated
weaklycorrelated
Correlation b/w parameter & DPR
