an evaluation of high impact weathers over korea simulated

Numerical Modeling Laboratory, Department of Atmospheric ScienceNumerical Modeling Laboratory, Department of Atmospheric Sciences, Yonsei Universitys, Yonsei University

An Evaluation of HighAn Evaluation of High‐‐Impact Weathers over Korea Impact Weathers over Korea Simulated by the Simulated by the

NonNon‐‐Hydrostatic Regional Spectral ModelHydrostatic Regional Spectral Model

EunEun‐‐Chul Chang Chul Chang and

SongSong‐‐You HongYou Hong

Numerical Modeling Laboratory, Yonsei UniversityNumerical Modeling Laboratory, Yonsei University


IntroductionIntroduction

•

Most regional models employ the nonnon‐‐hydrostatichydrostatic

dynamics as a dynamical core

•

Non‐hydrostatic forcing is important at higher resolutionat higher resolution

when dynamical and

thermodynamical forcing are strong

GlobalGlobal

and and RegionalRegional

Integrated Model System (Integrated Model System (GRIMsGRIMs))

Regional Spectral Model (RSM) in GRIMs

▪

Widely used for climate researches (>50km)

▪

For high‐resolution (<10km) climate simulation, non‐hydrostatic system is highly needed

Non‐hydrostatic version of NCEP RSM (Juang 1992, 2000(Juang 1992, 2000) is implemented to GRIMs


IntroductionIntroduction

GlobalGlobal

and and RegionalRegional

Integrated Model System (Integrated Model System (GRIMsGRIMs))

Spectral dynamic core : T62 Spectral dynamic core : T62 ―― T426T426

1. Spherical harmonics (SPH) system1. Spherical harmonics (SPH) system

: for Global and Regional: for Global and Regional

2. Double Fourier series (DFS) system2. Double Fourier series (DFS) system

: for Global: for Global

Physical processesPhysical processes

Land surfaceLand surface Kang and Hong (2008, JGR), Chen and Duhdia (2001, MWR)Kang and Hong (2008, JGR), Chen and Duhdia (2001, MWR)

PBLPBL Hong et al. (2006, MWR), Noh et al. (2003, BLM)Hong et al. (2006, MWR), Noh et al. (2003, BLM)

CumulusCumulus Byun and Hong (2007, MWR), Park and Hong (2007)Byun and Hong (2007, MWR), Park and Hong (2007)

Cloud and microphysicsCloud and microphysics Hong et al. (1998, MWR; 2004, MWR)Hong et al. (1998, MWR; 2004, MWR)

RadiationRadiation Chou (2006), Ham et al. (2009, ATP)Chou (2006), Ham et al. (2009, ATP)

Gravity wave dragGravity wave drag Chun and Baik (1998, JAS), Kim and Arakawa (1995, JAS), Chun and Baik (1998, JAS), Kim and Arakawa (1995, JAS), Hong et al. (2008, WAF)Hong et al. (2008, WAF)


Experimental designExperimental design

Two regional models are utilized in this studyTwo regional models are utilized in this study

Regional Spectral Model (RSM)Regional Spectral Model (RSM)

Weather Research and Forecasting (WRF) modelWeather Research and Forecasting (WRF) model

RSMRSM

WRFWRF

HydrostaticHydrostatic

NonNon‐‐hydrostatichydrostatic


NonNon‐‐hydrostatichydrostatic

Case 1 : Case 1 : 2005. 4. 4. 12UTC – 4. 6. 00UTCdown slope severe wind storm case(Lee wave)

Case 2 : Case 2 : 2005. 12. 21. 00UTC – 12. 22. 00UTCHeavy snowfall case

Case 3 : Case 3 : 2006. 7. 15. 00UTC – 7. 16. 00UTCHeavy rainfall case

Domain1 (27km)Domain1 (27km)

Domain2 (9km)Domain2 (9km)

Regional Model Domains :Regional Model Domains :

Lambert conformal conic map projectionLambert conformal conic map projection

4 domains are used for downscaling 4 domains are used for downscaling

11‐‐way nesting (27km way nesting (27km ––

9km 9km ––

3km 3km ––

1km)1km)

NCEP Final Analysis Data (FNL, 1NCEP Final Analysis Data (FNL, 1⁰×⁰×

11⁰⁰))

is used for I.C. and B.C.is used for I.C. and B.C.

Dm 1 Dm 2 Dm 3 Dm 4

RSM 60 s 20 s 6 s

WRF 90 s 30 s 10 s 3 s

time step (time step (∆∆t) for integrationt) for integration


ObjectiveObjective


ObjectiveObjective

For the WRFWRF

model and RSM,RSM,

the non‐hydrostatic

and hydrostatic

versions are available.

Evaluate high‐impact weathers simulated by the non‐hydrostatic models

Find out advantages of the non‐hydrostatic dynamical cores in high resolution


Result 1Result 1

Case 1 : downslope windstorm (Lee wave)Case 1 : downslope windstorm (Lee wave)


Domain 1 (27km) : 850 hPa geopotential height (m), wind vectorDomain 1 (27km) : 850 hPa geopotential height (m), wind vectorCase 1 : downslope windstorm (Lee wave)Case 1 : downslope windstorm (Lee wave)

WRFWRF

RSMRSM


HydrostaticHydrostatic NonNon‐‐HydrostaticHydrostatic

NonNon‐‐HydrostaticHydrostatic

36hr fcst


Domain 1 (27km) : 500 hPa geopotential height (m), wind vectorDomain 1 (27km) : 500 hPa geopotential height (m), wind vector

WRFWRF

RSMRSM




36hr fcst



Domain 3 (3km) : topographyDomain 3 (3km) : topography

RSM domain3RSM domain3


WRF domain3WRF domain3


WRF WRF ––

Domain 3 (3km) : 850 hPa vertical velocity (m/s)Domain 3 (3km) : 850 hPa vertical velocity (m/s)



WRFWRF

WRFWRF

2005. 4. 5. 12 UTC2005. 4. 5. 12 UTC 2005. 4. 5. 15 UTC2005. 4. 5. 15 UTC 2005. 4. 5. 18 UTC2005. 4. 5. 18 UTC




RSM RSM ––

Domain 3 (3km) : 850 hPa vertical velocity (m/s)Domain 3 (3km) : 850 hPa vertical velocity (m/s)




RSMRSM

RSMRSM




WRF WRF ––

Domain4 (1km) : Vertical velocity (m/s) at z = 2 kmDomain4 (1km) : Vertical velocity (m/s) at z = 2 km



WRF WRF ––

Domain 4 (1km)Domain 4 (1km)

5

4

3

2

1

0


Cross section : vertical velocity & potential temperature


Result 2Result 2

Case 2 : Heavy snowfallCase 2 : Heavy snowfall


Domain 2 (Domain 2 (9 km9 km): total precipitation (mm) for 24 hours): total precipitation (mm) for 24 hoursCase 2 : Heavy snowfall (2005. 12. 21. 00UTC ~ 12. 22. 00UTC)Case 2 : Heavy snowfall (2005. 12. 21. 00UTC ~ 12. 22. 00UTC)

WRFWRF(WSM6)(WSM6)

RSMRSM(WSM1)(WSM1)



NonNon‐‐HydrostaticHydrostatic TMPATMPA


Domain 3 (Domain 3 (3 km3 km): total precipitation (mm) for 24 hours): total precipitation (mm) for 24 hoursCase 2 : Heavy snowfallCase 2 : Heavy snowfall

RSMRSM

WRFWRF



NonNon‐‐HydrostaticHydrostatic diff (nonhydro diff (nonhydro ––

hydro)hydro)


Result 3Result 3

Case 3 : Heavy rainfallCase 3 : Heavy rainfall


Domain 2 (Domain 2 (9 km9 km): total precipitation (mm) for 24 hours): total precipitation (mm) for 24 hoursCase 3 : Heavy rainfallCase 3 : Heavy rainfall

WRFWRF(WSM6)(WSM6)

RSMRSM(WSM1)(WSM1)




TMPATMPA


Domain 3 (3Domain 3 (3

kmkm): total precipitation (mm) for 24 hours): total precipitation (mm) for 24 hours

Case 3 : Heavy rainfallCase 3 : Heavy rainfall

RSMRSM

WRFWRF





SummarySummary


SummarySummary

•

For short range forecast, there are no significant differences of results

between the hydrostatic and non‐hydrostatic dynamics cores in coarse

resolution domains (< 9 km).

•

For high resolution ( > 3 km), non‐hydrostatic dynamics frames can

generate lee wave propagation, and more strong vertical motions

which

increase precipitation.

•

Advantages of the Non‐hydrostatic dynamic core for high resolution (<10

km) climate run.


Plan Plan

•

Blow up problems

•

Advantages of the Non‐hydrostatic dynamic core for high resolution (<10

km) climate run.


Thank you


Domain 4 (Domain 4 (1 km1 km) : total precipitation (mm) for 24 hours) : total precipitation (mm) for 24 hoursCase 2 : Heavy snowfallCase 2 : Heavy snowfall

WRFWRF

HydrostaticHydrostatic NonNon‐‐HydrostaticHydrostatic diff (diff (nonhydrononhydro

––

hydro)hydro)


NonhydrostaticNonhydrostatic

Primitive EquationsPrimitive Equations

22

22

1 1ln

1 1ln

s bu

s bv

Q uu u u u mm u v E fv R T Ft x y x x x t

Q vv v

Q T QTT

v v mm u v E fu R T FQ Tt x y y y y t

QTT

wt

12

0

2 2

2 1 1 1ln

s s s sbQ

kk s

T

w

s

b

Q Q Q Qu um u v dt x y x y t

Q QT T T Tm u v T m ut x y t

ww w w T Qm u v g

x

Fx y tT

2 23

2 2 2 2

2

V+

s

s s sT

ksk s

T

T

s

b

b

Q Q Q Q QQ Q Fm u m vt x y T t

T T Q Q Q Q Q Q TT T T T T Qm u m v T T m u m v Ft x y t x

Q

y

Tm v F

t

y t

2 2 bq

qq q q qm u m v Ft x y t

Fully compressible Fully compressible nonhydrostaticnonhydrostatic

RSM (Juang 2000) RSM (Juang 2000)

'( ln ), ', Q p T w




Fully compressible Fully compressible nonhydrostaticnonhydrostatic

equations equations : calculation of sigma dot ( ): calculation of sigma dot ( )

2g w m u vt x yRT RT

1 2 2

0

Q Q u v Q Q u vm u v d m u vx y x y x y x y

Hydrostatic Hydrostatic : use pressure and wind: use pressure and wind

NonhydrostaticNonhydrostatic: use vertical velocity (directly) : use vertical velocity (directly)

)ln(

)ln(

ss pQpQ



Hydrostatic

Nonhydrostatic

2

2 1 1ln

s bu

Q T QT Q uu u u u mm u v E fv R T Ft x y x x xT t

22 s b

uQ uu u u u mm u v E fv RT F

t x y x x x t

2 21

2E u v

T

Q

T

Q

T

Q

Hydrostatic part

perturbation part

)ln()ln(

ss pQpQ

Q Q Q

lnsQ Q

2

22 2 con

s1 1l

s Q T QQu u u u mm u v E fv R Tt x

uTy x Tx

wax

w


Current statusCurrent status

2 23 V+s s sTQ Q Q Q QFQ Qm u m v

t x y T t

12

0

s s s sbQ

Q Q Q Qu um u v dt x y x y t

2 2 22 s s

k

sk bT

T T TT T T T Tm u m v T T Ft x y

Q Q Q Q Q Q Qm u vt x y t

m

2

2 1l

1n

s bu

Q Q uu u u u mm u v E fv R T T T QT

Ft x y x x x t

2

ln1 1 1 b

www w w wm u v Tg F

t x y tQ

T

2wg m u vt x yRT RT

23 V= u v u v gm

x y x y Tw

RT R


PressurePressure

Hydrostatic PressureHydrostatic Pressure

NonhydNonhyd

Q Q ––

hydro Q : Get pressure perturbationhydro Q : Get pressure perturbation

NonhydNonhyd

T T ––

hydro T : Get temperature perturbationhydro T : Get temperature perturbation

'( ln ), ', Q p T w


Future planFuture plan

Lee wave is a “pure dynamics”

phenomena

tested when the dynamic core is developed

check for RSM non‐hydrostatic frame

Suggested cases Suggested cases

Test dynamical core + phenomena

1. development of the convection cell

Lake effect snow storm over the East (West) sea of Korea

2. dynamically strong cyclogenesis

cyclogenesis

and it’s development in front of the Siberian High

Cloud streetCloud street

an evaluation of high impact weathers over korea simulated

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