Current Status and Issues On the Parameterizations of Convective Gravity Waves

Transcription

1 Curren Saus and Issues On he Parameeriaions of Conveive Graviy Waves Hye-Yeong Chun Deparmen of Amospheri Sienes, Yonsei Universiy, Souh Korea

2 Ouline Developmen hisory of onveive GWD (CGWD) parameeriaions Ray-based CGWD parameeriaion Some issues on CGWD parameeriaions Realiy of soure-level (loud-op) momenum flux sperum Using saellie daa o onsrain soure-level momenum flux Coupling GW momenum flux ih loud momenum flux Inluding effes of he seondary GWs generaed by breaking of onveive GWs

3 Parameeriaions of Conveive GWs Firs generaion: Rind e al. 1988: ave momenum flux is proporional o onveive mass flux Kersha 1995: ave energy above onveion is proporional o onveive kinei energy in he loud region Seond generaion: Chun and Baik 1998, : analyial formulaion of ave momenum flux indued by speified diabai foring in a uniform/sheared bakground ind Chun e al. (1, YONU GCM), Kim and Hogan (, NOGAPS), Chun e al. (4, CCM3), Kim e al. (7, GDAPS) Waves saionary relaive o onveive soures are onsidered Third generaion (Speral CGWD parameeriaions): Beres e al. (4), Beres (4) uniform basi-sae Song and Chun (5) shear flo ih sabiliy differene Kim and Chun (5) muliple aves in Chun and Baik () s Chun e al. (8) inlude nonlinear foring effe in Song and Chun (5) s Beres e al. (6, WACCM), Song e al. (7, WACCM) Spaioemporal variaions of soure sperum an be inluded in he speral GWD parameeriaion

4 A Ne Conep of GWD Parameeriaion Assumpions in he urren onveive GWD parameeriaions Column-based parameeriaion GWs propagae only in he verial direion GWs propagae from a soure level o model op ihin one GCM ime sep Hoever, onveive GWs an propagae horionally as far as 1 km hen hey reah he middle amosphere I is neessary o develop a ne onveive GWD parameeriaion ha inludes horional as ell as verial ave propagaions based on he ray heory Holon and Alexander (1999)

5 LSGWDC: Lagrangian (Ray-based) Speral Conveive GWD Parameeriaion Referene-level (loud-op) graviy-ave properies avenumbers, frequeny, pseudomomenum flux are obained a loud op (k, l, m, ω, k g A, and l g A) using Song and Chun (5) s formulaion Wave propagaion Calulaion of a rajeory of eah ray and ampliude of he momenum flux folloing he ray (3-D ray-raing model) Wave breaking and dissipaion Linden-ype mehod based on Kiehl e al. (1996) Sauraion hreshold Wave diffusion Deposiion of GW momenum flux Song and Chun (8, JAS)

6 NCAR Whole Amosphere Communiy Climae Model (WACCM1b) Dynamis Global speral model [T63 (18x64), semi-lagrangian ehnique] 66 verial levels from he ground o abou 14 km Verial resoluion: less han 1.5 km belo he loer srsosphere, 3.5 km in he mesosphere and above Physis mosly he same as in CCM3 Addiional proesses for beer simulaion of middle amosphere Nonorographi graviy aves (GWD) Nonloal hermodynami equilibrium longave ooling Shorave heaing for upper amosphere Moleular visosiy Ion drag Loss raes of green house gases and phoolysis raes of aer vapor

7 Propagaion of Rays (1 day, no ineraive in WACCM1b) Trajeories of inernal graviy ave pakes generaed by deep onveion a 18.1S, 19E a UTC on 1 January 1979 Horional exen of propagaion an be 1- o Meridional propagaion is relaively symmeri and aves propagae a grea disane esard Zonal propagaion is asymmeri due o Doppler shifing by he easerly flo

8 Climae Simulaions (6 yrs, ineraive): Cloud-Top Momenum Flux Sperum 7.5 yr simulaion ih limaologial SST and oone in WACCM1b

9 Zonal-mean onal drag (6 yr, ineraive) SGWDCRW: Song and Chun (5) ih refleion and WKB ondiion Generally similar ih eah oher: negaive drag in he iner mesosphere and mos sraosphere and posiive drag in he summer mesosphere Magniude of drag foring inreases in he LSGWDC simulaion -Waves an be onverged horionally - The lo-frequeny aves an say longer in he ropial region

10 Validaion of LSGWDC Compared ih Saellie Observaions Observaions Upper Amosphere Researh Saellie (UARS) Miroave Limb Sounder (MLS) GW emperaure varianes a 38 km repored by Jiang e al. (4, JGR) Period 1) Deember-Marh (DJFM) ) June-Sepember (JJAS) 1993 Inpu daa for LSGWDC parameeria ion DCH (Deep Conveive Heaing rae) - NCEP/NCAR reanalysis daa (19 94 Gaussian grids, 6 hourly) Bakground fields (U,V,T) - ECMWF reanalysis daa [3 pressure levels (1-1 hpa),.5 o.5 o grids, 6 hourly] Wave launh frequeny: 6 hr For omparison ih MLS daa (λ x < 1 km, λ > 1 km), a 3-D MLS analyial filer funion a 38 km by Jiang e al. (4b, JGR) is used Choi e al. (9, JGR)

11 Comparison ih MLS GW Temperaure Variane

12

13 Verial avelengh λ n λ GWTV n n GWTV n n λ due o reduion of he GWs ih small verial avelengh by he riiallevel filering, and his is signifian in he souhern subropial region here sraospheri easerly ind shear is srong. Smaller λ over he sraosphere in he LSGWDC parameeriaion due o long lasing GWs ih small group veloiies ( g λ )

14 Some Issues on he CGWD Parameeriaions Realiy of he soure-level (loud-op) momenum flux sperum Ho global observaion daa ses an be used for he validaion and developmen of CGWD parameeriaion Coupling GW momenum flux ih loud momenum flux Inluding effes of seondary GWs generaed by breaking of onveive GWs

15 Cloud-op Momenum Flux Sperum x v x u T gq N y b V x b U b b x d du y u V x u U u p φ φ ) ( ) ( ) ( ) ( ) ( y Q x Q T g y x N y D D d V d x D D d U d D D p Fourier ransform in x, y, and ( ) ( ) ( ) ˆ ˆ ˆ U T gq U d U d U N p Governing equaions In he hree-dimensional, hydrosai, nonroaing, invisid, and Boussinesq airflo sysem, governing equaions for small perurbaions fored by a diabai foring (Q) are rien as Song and Chun (5, JAS) y V x U D D ϕ ϕ ϕ sin ) ( ) os ( ), ( V U U / h, k ω l k k h

16 Three-layer amosphere and analyial soluion ( ) ( ) b i i Q e B e A s s ζ λ λ ~ ˆ du d U U N U N 1 1 and,, 1 4, Ri α λ λ μ ( ) ( ) μ α μ α i i B A ˆ 1 ( ) ( ) i i B e A e ˆ λ λ Boundary ondiion a, inerfae ondiions a b, s, and, and upper radiaion ondiion as goes infiniy. A 1, B 1, A, B, A 3, B 3, A 4, and B 4 are deermined ( ) ( ) a i i Q B A ζ μ α μ α ~ ˆ foring of funion sruure verial, ˆ ~ 1 q p N T gq Q ζ ( ) [ ] soluion hen : pariular ~ ~ d du Q Q s q a ζ ζ ζ ( ) [ ] soluion hen : pariular ~ ~ d du Q Q u q a ζ ζ ζ ( ) ( ) ( ) exp exp exp,, h qy h qx y y x x Q y x Q δ δ δ

17 Cloud-op momenum flux sperum M X (, ϕ, ) sgn [ U ( ϕ )] : ρ ( π ) A dependen on basi-sae ind and sabiliy from he surfae o loud op and he verial onfiguraion (sruure, heigh, and deph) of diabai foring: h L 3 p T g N q N U X WFRF ( ϕ ) Θ (, ϕ ) Soure Wave-filering-and-resonane-faor (WFRF) ave filering by he verial propagaion ondiion resonane beeen he verial harmonis onsising of onveive soure and naural ave modes ih he verial avenumbers given by he dispersion relaion of inernal GWs Conveive soure sperum Θ(, ϕ) q δ hδ 3 / 3π 1 1 ( qh ) /, δ h, δ : spaial and ime sales of he onveive soure), o δ h / δ qh : moving speed of he onveive soure:

18 Some Issues on he CGWD Parameeriaions Realiy of he soure-level (loud-op) momenum flux sperum Validaed Song and Chun (5) based on he expliily alulaed 3-D onveive graviy aves using he WRF model for various ideal and real sorm ases Deermined o free parameers in he parameeriaion Parameeriaion is ell mahed ih he simulaions (Choi and Chun, 11, JAS, in press: Hyun-Joo Choi ill presen resul in his session) Ho global observaion daa ses an be used for he validaion and developmen of CGWD parameeriaion Coupling GW momenum flux ih loud momenum flux Inluding effes of seondary GWs generaed by breaking of onveive GWs

19 Some Issues on he CGWD Parameeriaions Realiy of he soure-level (loud-op) momenum flux sperum Ho global observaion daa ses an be used for he validaion and developmen of CGWD parameeriaion Coupling GW momenum flux ih loud momenum flux loud momenum flux profile in he loud region should be ombined ih GW momenum flux profile above o make a momenum onservaion Inluding effes of seondary GWs generaed by breaking of onveive GWs

20 Limiaion in using saellie daa for validaion/developmen of CGWD parameeriaion Wu e al. (6, Adv. Spae Res.)

21 Graviy Wave Temperaure Variane alulaed using reanalysis daa (NCEP diabai heaing, ERA-Inerim ind and emperaure) and ray-based CGWD parameeriaion by Song and Chun (8) AIRS Filered GWTV (15 January, 5) Para x 8

22 Conveive GWs Observed in AIRS Correlaion beeen onveive aiviy and graviy ave aiviy is srong in a ore onveion region, bu no in oher regions Dire orrelaion beeen onveive soures and graviy aves an be valid for only highfrequeny aves, and horional propagaion from he soure regions should be onsidered for relaively lo-frequeny aves generaed by onveive soures Ray-based CGWD parameeriaion is required : should ray-based CGWD parameeriaion more be effiien for use in GCMs Hoffman and Alexander (1, JGR)

23 Some Issues on he CGWD Parameeriaions Realiy of he soure-level (loud-op) momenum flux sperum Ho global observaion daa ses an be used for he validaion and developmen of CGWD parameeriaion Coupling GW momenum flux ih loud momenum flux loud momenum flux profile in he loud region should be ombined ih GW momenum flux profile above o make a momenum onservaion Inluding effes of seondary GWs generaed by breaking of onveive GWs

24 Coupling GW and Cloud Momenum Fluxes Cloud momenum flux assoiaed ih organied onveive sysem should be inluded in GCMs (Wu and Yanai, 1994, Wu and Monrieff 1996), for beer represenaion of umulus onveion, espeially he loaion Momenum onservaion inluding loudmomenum flux profile is required: urrenly add ompensaing GW momenum a he upper fe levels of umulus louds (Chun and Baik, 1998, ; Song and Chun, 5) Z U U mt T ZmT U ρ ρ ρ T Lane and Monrieff (1, JAS) T U U ρ ρ Z mt T

25 Some Issues on he CGWD Parameeriaions Realiy of he soure-level (loud-op) momenum flux sperum Ho global observaion daa ses an be used for he validaion and developmen of CGWD parameeriaion Coupling GW momenum flux ih loud momenum flux loud momenum flux profile in he loud region should be ombined ih GW momenum flux profile above o make a momenum onservaion Inluding effes of seondary GWs generaed by breaking of onveive GWs

26 Effes of Seondary Waves -D APRS model simulaion of onveive GWs Chun and Kim (8, JGR) Seondary aves generaed by nonlinear momenum foring by breaking of primary aves an influene on momenum profile signifianly above and belo he ave breaking region

27 Thank you for your aenion Lab. for Amospheri Dynamis, NRL