Presentation is loading. Please wait.

Presentation is loading. Please wait.

An overview of the KIAPS numerical weather prediction systems

Similar presentations


Presentation on theme: "An overview of the KIAPS numerical weather prediction systems"— Presentation transcript:

1 An overview of the KIAPS numerical weather prediction systems
Song-You Hong and KIAPS staffs (Korea Institute of Atmospheric Prediction Systems: KIAPS)

2 Three-stage development plan of KIAPS Global Model
step3 step2 . ■ Finalize the KIAPS operational version 1.0 and run on semi-operational basis ■ Stabilize the model system by further diagnostics and verifications ■ Release the KIAPS system to international users Finalize the operational system step1 Release beta version ■ Complete developing major model components based on KIAPS own research ■ Release the KIAPS beta version model ■ conduct semi realtime experiments with KIAPS beta version and evaluate it skills to the KMA operational model Foundation and basic research ■ Establish the foundation of KIAPS research and development environment ■ Efforts on laying out future model development – model dynamics, physics and data assimilation

3 Spectral element method
KIM Configuration (2016.8) scheme References Numerical model -Dynamical core -Physics Equation Nonhydrostatic Choi et al. 2014 Choi and Hong 2016 Horizontal discretization Spectral element method Radiation RRTMG Iacono et al. 2008 Land surface Noah V3.4.1 Ek et al. 2003 Koo et al. 2016 Ocean surface layer Kim and Hong Kim and Hong 2010 Vertical diffusion YSU ShinHong Hong et al. 2006 Shin and Hong 2015 Lee et al. 2016 Gravity wave drag O: Kim-Arakawa Hong et al. 2008 Choi and Hong 2015 C: Chun and Baik Chun and Baik 1998 Deep conv. SAS Han and Pan 2011 Lim et al. 2014 Han et al. 2016 Shallow conv. GRIMs Hong et al. 2013 Microphysics WSM5 Hong et al. 2004 Bae et al. 2016 Cloudiness Prognostic Park et al. 2016 Assimilation OPS KPOP Var 3DVar Song and Kwon 2015 LETKF Framework Semi-real run Cylc

4 Dynamical core

5 Atmospheric Model test
Development of Non-hydrostatic Dyn. WRF governing equations are adapted - Cubed sphere, horizontal: Spectral element, vertical: FD, terrain-following - Flux-type compressible governing equations in perturbation form with prognostic variables - Time-split time integration: Slow mode  third-order Runge-Kutta Horizontal sound wave and gravity wave  Forward-Backward vertical sound wave and buoyancy  implicit 2D Shallow Water Test 2D (x-z) Slice Dry Dynamical Core Tests 3D Dry Dynamical Core Tests 3D Aqua-Planet Experiments (APE) 3D Atmospheric Model test 1. Advection of cosine bell 2. Steady state 3. Translating low 4. Zonal flow over an isolated mountain 5. Rossby-Haurwitz wave 1. Linear hydrostatic mountain wave 2. Simulations The Schar-type mtn. 3. Density current 4. Inertial-gravity wave 5. Rising thermal bubble (Choi et al., 2014) 1. Steady-sate 2. Baroclinic wave 3. 3D Rossby-Haurwaitz wave 4. Mountain-induced Rossby wave 5. Pure gravity wave 6. DCMIP pure advection test 7. DCMIP Mountain-wave over a Schar-type 8. Held-Suarez 1. Control APE 2. 3KW1 APE 1. the 5-case for a severe weather 2015 (Choi and Hong, 2016)

6 Increase the order of the diffusion operator
The fourth-order diffusion scheme  sixth-order diffusion Outer loop time-split horizontal diffusion (5 times per a time-march) Increased dt and enhanced energy spectra are achieved. ne120 dt Diffusion order Diffusion Coeff. KIM2.2(CTL) 15 2 1.8E13 KIM2.3 60 3 3.0D21

7 New profiles of A and B for hybrid-sigma coordinate
Lower level associated with pure pressure coor. (15  33 hPa) To get rid of discontinuity for layer depth (dB/dη) TMPA OLD (50lev) KIM2.4 KIM2.5 NEW (50lev)

8 Variable resolution using Schmidt transform
[Example ne6np4 grid with Magnification factor S = 2] [Baroclinic Instability test at 9-day] [DCMIP51 – Idealized Tropical Cyclone experiment w/ simple-physics]

9 Physics modules

10 RADIATION V2.4 REDU-MCICA: Increase the efficiency of MCICA with keeping accuracy (reduced 30% computational time) SNOW ALBEDO: Improve the cold bias at the lower levels RRTMG O3 input data Improvement of upper level T forecast skills CTL GMAO TROP TROP

11 GWDO V2.4 Resolve the problem of too strong continental high pressure systems (Choi et al., in preparation) hr 1021 1019 UM(Anal) H: 1021 L1: 980 L2: 970 UM(Fcst) H: 1019 L1: 980 L2: 969 1030 KIM v2.1 (ORG: Alpert et al., 1988) H: 1030 L1: 961 L2: 955 1022 KIM v2.1 (updated: Choi-Hong, 2015) H: 1022 L1: 972 L2: 956 More GWD at low level→ reduce wind sfc wind speed → reduce mass convergence → weaker high

12 CPS V2.4| Entrainment: Increasing the dependency of environment moisture  increase entrainment rate in drier environment CPS trigger considering environment moisture  suppress triggering with the condition of dry low levels Improvement of precipitation forecast a SAS_MAY2016 a SAS_MAY2016 ETS against AWS (Korea) Bias against CPC (Global) Before After

13 PROGC+SCV V2.5| Modification of cloud formation for the supersaturated cloud in the prognostic cloud scheme Change of vertical diffusion profile for temperature and specific humidity Improvement of downward SW flux at surface CERES CTL MOD 178.6 W/m2 157.7 W/m2 166.6 W/m2 Improvement of temperature at lower level against sonde East Asia Europe East Asia Europe

14 GWDC V2.5 Stationary convective GWD in an uniform atmosphere (Jeon et al. 2010/Chun-Baik 1998) Spectral convective GWD (Song-Chun 2005; Choi-Chun 2010) Rayleigh friction or uppermost diffusion Spectral frontal GWD (Charron-Manzini 2002; Richter et al. 2010) Improvement of U wind against FNL analysis data and radiosonde JJA 2013 CTL MOD Feb. 2014 CTL MOD Contour: RMSE Shading: Bias RMSE = 2.713 PC=0.977 RMSE = 2.613 PC=0.980

15 KIAPS Package for Observation
Processing (KPOP) and Data Assimilation Systems (3DVAR and LETKF)  4D EnVar

16 KIAPS Package for Observation Processing (KPOP)
2013 2014 2015 2016 Conven-tional Data Sonde Surface Aircraft Satellite AMSU-A ATMS MHS IASI CrIS GPS-RO AMV ASCAT SSMIS Frameworks ODB (Obs. Data base) Comparison with KMA-op. Monitoring system Primitive Improved Semi-operational current

17 3DVAR Song and Kwon 2015 (MWR)
3DVAR system built on KIM (cubed sphere grid using Real-observations) For radiance assimilation, the Jacobian matrix gained from the KPOP system is used for operator (brightness temperature) The observation data assimilated so far Sonde, Surface, Aircraft, AMSU-A, IASI, GPO-RO, AMV, ATMS, CrIS, MHS, CSR, ScatWind Aircraft data assimilation RMSE 250hPa Results of 3DVAR system AMSU-A data assimilation

18 Development of hybrid DA Hybrid-4DEnVar
4D extension of 3DVAR (seven time bin for an analysis window) Error of the Day of error from LETKF Add alpha control variable for Ensemble background error Temperature and moisture improvement for all level ↑ RMSD of U analysis against UM analysis

19 Verification/Analysis
KIM 2.4 (Jul 2016)

20 Verification/Analysis Application (Physics)
NE60, 240-hr July 2013 AC of 500 hPa GPH (NH) Bias of 24-h Acc. Precip. (3-d avg) V2.3 : 0.832 V2.4 : 0.837 RMSE of 500 hPa GPH (NH) ETS of 24-h Acc. Precip. (3-d avg) 37.040 37.083 V2.3 : 38.48 V2.4 : 37.92 V2.3 V2.4 [against FNL analysis] [against TMPA observation (Global)]

21 Verification/Analysis Application (Physics)
Temperature bias (shade) and RMSE (contour) against sonde (+240 h forecast) KIM2.3 KIM2.4 Jul. 2013 (Tropics) Feb. 2014 (Asia)

22 Verification/Analysis KIM skill statistics
July 2013 case NH 500 hPa GPH AC NH 500 hPa GPH RMSE UM: N512 GDPS KIM: NE60 with GFS analysis

23 Verification results of semi-real run (2016. 7)

24 Verification for rain against CPC (July 2016)
Tropics GLOB KIM-COLD KIM (~25km) with UM initial condition +240h forecast at 00, 12 UTC KIM-WARM KIM (~25km) with 3DVAR (~50km) +240h forecast at 00, 12 UTC +6h forecasts at 06, 18 UTC

25 Monthly verification statics
KIM v2.1 v2.2 v2.3 v2.4 NH 500 hPa GPH AC NH 500 hPa GPH RMSE

26


Download ppt "An overview of the KIAPS numerical weather prediction systems"

Similar presentations


Ads by Google