Multi-modal Multi-moment Aerosol-Cloud Interaction Schemes

Transcription

1 Multi-modal Multi-moment Aerosol-Cloud Interaction Schemes Workshop on Aerosol, Cloud, Climate and Chemistry, November 5-6, 2012, Academia Sinica, Taipei

2 dm k dt = K r, air rk n r dr n(r) K(r,air): growth kernel n(r): size distribution function n r = N r ln2 ( 2πrσ exp μ ) 2σ 2 (log-normal) r n r = Nr i exp λr j (gamma-type)

3 Traditional (Kessler-type) parameterization scheme basic physical equations Physical-statistical parameterization scheme (Chen & Liu 2004) basic physical equations analytical solution empirical solution off-line detailed discrete model calculation statistical analyses bulkwater equation bulkwater equation

4 using bin models binned conversion rates multi-component bin model Dn Dn water bin # solute bin # Dn bulk conversion rates r r

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6 bulkwater cloud microphysics Bulk parameterization Chen and Liu (2004) Cheng et al. (2007, 2010) Water Vapor CCN GCCN - Activation + + Deactivation - Cloud drops Cloud ice + Nucleation - IN IN Chen et al. (2008) Hoose et al. (2010) - Activation + Rain Snow Graupel CCN, GCCN Chen and Liu (2004) Cheng et al. (2007)

7 Real/spherical ice crystal shape effects aspect ratio a c Terminal velocity, m/s Fall speed 5 4 Deposition growth 5 C / r eq Equivalent radius, mm asymmetry factor Aspect ratio Collision efficiency, etc. Transmission:scattering (Yang and Fu, 2009)

8 Inherent growth ratio Adaptive growth habit parameterization (with shape memory) G(T) G(T) = 0.5 < 300 s = 2.0 > 300 s b) Shape moment: M φ = r 3 φ n r dr c) For g distribution n( r) N0r exp( r) N Γ(3ζ + α + 4) M φ = 3ζ Γ(1+α) r 0 λ 3ζ+3 Time, s

9 Physics-based multi-modal 3-moment Aerosol Parameterization (PAP) sulfate/ Tsai (2009) nitrate/ ammonium mineral dust basic physical equations binned offline integration EC OC sea salt 0.01 statistical analyses dm dt k bulk formula Cair func( M 0, M 2, M 3) Aerosol mixing states Processes: emission, nucleation, condensation, dry deposition, Intermodal coagulation, intra-modal coagulation, scavenging

10 parameterization parameterization accuracy (Intra-modal Brownian coagulation) dm 0 /dt dm 2 /dt Detailed calculation Detailed calculation 24hr R 2 (error) Gauss-Hermit quadrature Gauss- Hermit B95_fast B95 fast PAP PAP M (3.88%) (20.01%) (10.4%) M (3.43%) (243.6%) (6.83%) Numerical (100bins) CPU time

11 dn/dlngd(cm-3) compare with bin model (parcel simulation) 1e+6 1e+5 1e+4 1e+3 1e+2 1e+1 1e Particle diameter(mm) M0(#/m 3 ) 1e+11 1e+10 number Initial detail model_m0 B95_M0 ICAPs_M0 M0 ds/dlogd(mm2/cm3) detail model B95 PAP Particle diameter(mm) M2(m 2 /m 3 ) 9e-5 8e-5 7e-5 surface M2 dv/dlngd (mm3/cm3) dn/dlngd(cm- 1e+4 1e+3 1e e+1 1e Particle diameter(mm) 1 volume detail model B95 PAP Particle diameter(mm) Initial detail model_m0 B95_M0 ICAPs_M Time(s) 6e Time(s) 24 hr error B95 PAP M % -2.62% M % 1.35 %

12 Bin vs. modal comparison regional dust TAQM/kosa 72 hr simulation M0 M2 M3 PAP M0 M2 M3

13 number density (dn/dr) number density (dn/dr) number density (dn/dr) Bin vs. modal comparison size distribution 1.E+24 1.E+23 1.E+22 1.E+21 1.E+20 1.E+19 1.E+18 1.E+17 1.E+16 1.E+15 1.E+14 1.E+13 1.E+12 1.E+11 1.E E, 37 N 125E, 37N (Korea) t=72 dust size distribution detail parameterized 1.E E E E E E-04 particle radius (m) 1.E+24 1.E+23 1.E+22 1.E+21 1.E+20 1.E+19 1.E+18 1.E+17 1.E+16 1.E+15 1.E+14 1.E+13 1.E+12 1.E+11 1.E+10 1.E E, 40 N 110E, 40N (emission area) t=72 dust size distribution 1.00E E E E E-04 particle radius (m) detail parameterized 1.E+24 1.E+23 1.E+22 1.E+21 1.E+20 1.E+19 1.E+18 1.E+17 1.E+16 1.E+15 1.E+14 1.E+13 1.E+12 1.E+11 1.E+10 1.E E, 35 N 130E, 35N t=72 (Japan) dust size distribtion 1.00E E E E E-04 particle radius (m) detail parameterized

14 Number density Number density Number density multi-modal aerosol mixtures dust/soot hygroscopic aerosol mixture size size size dust

15 Aerosol-cloud interactions Activation: CCN, GCCN, mixture, surfactant Nucleation: mineral dust, soot, bio-aerosols Radiation: cloud burning (dust, soot) Scavenging: in cloud, below cloud existing ongoing planning Water Vapor CCN - Activation + + Deactivation - Cloud drops Cloud ice + Nucleation - IN GCCN - Activation + Rain Snow Graupel

16 log d N / dlog r Aerosol activation into cloud & rain Köhler curve S max nuclei mode S accumulation mode coarse mode r cut 10 m rain embryo log r r* DS* DS* 3b a S * 1 2a r / 3 * 3 4a 27b 16

17 Ice nucleation scheme thermodynamic parameters determined from laboratory data J A r 2 N f D g # exp A, Dg g : ambient parameters f: geometric factor Dg kt function of ambient parameter and wetting coefficient Properties of ice nuclei: (1) r N particle radius (2) Dg # activation energy (3) m wetting coefficient or q contact angle g f species parameter θ Δg # soot E. herbicola P. syringae P. aeruginosa Grass Oak Pine Birch Eucalyptus China rose Hematite (0.03) Hematite (0.13) Asian dust Saharan dust Arizona test dust (Chen et al. 2008)

18 Aerosol effect on Thphoon Nari (2001) Nari 2001 Sep. 06~21 Track comparison JTWC CWB 1612Z 1512Z

19 structure Z Z Z Z Urban Marine

20 rainfall

21 WRF-CHEM (CLR2+PAP) Simulation Cloud Ice Snow Grauple Rain

22 WRF-CHEM (CLR2+PAP) Simulation CCN in cloud

23 Aerosol effect on Thphoon Nari -- summary Under more polluted condition, the convections of rainband become more active and produce more extended stratiform region The squall-line-like structure of the rainband, including the rear inflow that brings in mid-level dry air, becomes more prominent under urban aerosol scenario. Enhanced hydrometeor s evaporation in the stratiform region leads to convection invigoration which intensifies rainband development and thus strengthens the convergence and the circulation. Rear inflow * * * * * * * * * * * * * * * * * * * ** * * * * * * Bright band Heating vertical profiles indicate that urban aerosol enhance high-level heating and mid-low level cooling during the rainband developing stage (typhoon intensification period). The asymmetric rainband heating effect may have influenced the track of this storm under weak steering-flow situation

24 -- thanks for your attention --