1 ENTRAINMENT and MICROPHYSICS in RICO Cu Hermann Gerber NASA/GISS Workshop Sept. 2006

2 Scorer, R.S., and F.H. Ludlam: 1953: Bubble theory of penetrative convection. Q.J. Roy. Meteor. Soc., 79, Erosion (Detrainment) Entrainment Rising Toroidal Thermal (Blyth, A.M., et al., 1988: J. Atmos. Sci., 45, ) (Baker, B., A., 1992: J. Atmos. Sci., 49, ) CLASSICAL ENTRAINMENT CONCEPT X (Damiani, et al, 2006: J. Atmos. Sci., 63, )

3 MICROPHYSICS ISSUES 2. What about entrained CCN? 1. Homogenous or inhomogeneous mixing? 3. Entrainment scales? 4. Super-Adiabatic Drops?

4 (Lasher-Trapp, S., W. Cooper, and A. Blyth, 2005: QJRMS, ) SUPER ADIABATIC ADIABATIC PEAK HOMOGENOUS MIXINGINHOMOGENEOUS MIXING

5 RICO FLIGHTS

6 CONDITIONAL SAMPLING FOR ACTIVE TURRETS VERTICAL VELOCITY IS POSITIVE (~80%) IN AREA WITHLWC VERTICAL VELOCITY IS POSITIVE (~80%) IN AREA WITH LWC TOP OF CLOUD IS VISIBLE IN FORWARD-LOOKING VIDEO A SINGLE TURRET IS TRAVERSED CLOUD IS TRAVERSED NEAR CLOUD TOP (Raga, G.B., et al, 1990: J. Atmos. Sci., 47, )

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8 (m)

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10 PVM FSSP Fast FSSP

11 PVM

12 10-cm RESOLUTION (1000 Hz) LWC DATA PVM

13 (Gerber, H., et al, 2001: J. Atmos. Sci., 58, ) (Burnet,F., and J.-L. Brenguier, 2006: J. Atmos. Sci., in print) (Schleuter, M.H., 2006: Master’s Thesis, U. of Utah) HOMOGENEOUS INHOMOGENEOUS EXTREME  or (Brenguier, J.-L.,and F. Burnet, 1996: 12 th Int. Conf. Clouds and Precip; Zurich; 67-70)

14 (Blyth A.M., and J. Latham, 1991: J.A.S., 48, ) (Gerber, H., et al, 2000: 13 th Int.Conf. Clouds and Precip., Reno, NV, )

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16 COMPOSITE OF 35 Cu IN

17 RICO, RF12  c  z  c  e   fractional entrain.  scalar = q T c = cloud e =environment COMPOSITE FRACTIONAL ENTRAINMENT. 0062

18 TKE (diss. rate) = [v’(rms)] 3 /L L = penetration length = 40m v’ = gust velocity COMPOSITE TKE DISSIPATION TKEINHOMOGENEOUS

19 CLOUD EDGE (Brenguier, J.-L, 1993: J. Appl. Meteor., 32, ) Hz

20 COMPOSITE OF ENTRAINED PARCEL LENGTH (Brenguier, J-L, and W.W. Grabowski, 1993: J. Atmos. Sci., 50, ) (Kreuger, S.K., et al, 1997: J. Atmos. Sci., 54, )

21 COMPOSITE OF ENTRAINED PARCEL PENETRATION

22 ENTRAINMENT SHEATH NO HOLES SMALL PARCELS DILUTION DOMINATES RH HALO? NEW CCN ACTIVATION VORTEX RINGS? SUPER-ADIABATIC DROPS? ENTRAINMENT CONCEPT X

23 TURRET SPECTRA

24 THANK YOU

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29 SPARE SLIDES FOLLOW

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32 Cu (Courtesy of Dr. Jim Hudson)

33  Turb. (s) = (D 2 / TKE diss. ) 1/3  Drop (s) = 4r 2 / [4x x (1-S)] RELAXATION TIME ANALYSIS D = entrained parcel width (m) r = droplet radius [ (m)]  Drop (s )  Turb. (s )  Drop (s )  Turb. (s ) R = >> 1 << 1 INHOMOGENEOUS MIXING HOMOGENEOUS MIXING

34 S  drop (s ) D(m)  turb (s) R RELAXATION TIME RATIO, R CLOUD #21

35 (Damiani, R., G. Vali, and S. Haimov, 2006: J.A.S., )