Entrainment Interface Layer (EIL) Analysis

Steve KruegerUniversity of Utah

1

from Burnet and Brenguier (2005)

Figure 3a : Scatterplot of qt vs. !l for the DYCOMS-II case (same data set as in Fig. 1). Different symbols are used for cloud, clear air and clear air samples adjacent to cloudy samples (edge samples), as indicated in the legend. Three saturation curves are drawn for 935, 942 and 950 hPa, as indicated by the labels. Isobaric mixing at 942 hPa between air from the free troposphere ("=0, !le=24.9 C, qve=5.1 g kg-1) and from adiabatic cloudy air ("=1, !li=15.5 C, qti=10.3 g kg-1) is represented by the solid straight line. This mixing line is graduated from 0 to 1 every 0.1. The error bar of the adiabatic cloud reference corresponds to an error of # 0.5 C on the estimation of the cloud base temperature. The two dashed lines are the constant virtual temperature lines corresponding to the free troposphere and to the adiabatic cloudy air. Frequency distributions of !l and qt are shown along the two axis for cloud, clear air and cloud edge samples separately.

- 42 -

LES (dx=6 m)Aircraft obs (10-m avg)

290 292 294 296 298 300

3

4

5

6

7

8

9

10

11

290 292 294 296 298 3000

0.5

Liquid Potential Temperature (K)

0 0.53

4

5

6

7

8

9

10

11

Tota

l Wat

er M

ixing

Rat

io (g

/kg)

Frequency

Figure 11: Scatter plot for liquid water potential temperature and total water mixing ratio from 100 meters belowcloud top to 50 m above cloud top for cross section x=250 at the native grid. Black points denote cloud cells, redpoints denote cloud adjacent cells, and blue points denote cloud free cells. Histogram at left/bottom for total watermixing ratio/liquid potential temperature where black bars denote cloud cells, red bars denote cloud adjacent cells, andblue bars denote cloud free cells.

13

Burnet and Brenguier (2006)

LES (dx=6 m)Aircraft obs (10-m avg)

Figure 1 : Vertical profiles of !l (left) and qt (right) for the 14 traverses of the cloud top profiling circle of the DYCOMS-II RF03 flight between 11:45 and 12:17 UTC. Cloudy samples (N>3 cm-3) are in black and clear air samples are in grey. The altitude is relative to the height of the inversion determined for each profile separately.

- 40 -

from Burnet and Brenguier (2006)

Aircraft obs (10-m avg)

Figure 1 : Vertical profiles of !l (left) and qt (right) for the 14 traverses of the cloud top profiling circle of the DYCOMS-II RF03 flight between 11:45 and 12:17 UTC. Cloudy samples (N>3 cm-3) are in black and clear air samples are in grey. The altitude is relative to the height of the inversion determined for each profile separately.

- 40 -

LES (dx=6 m)

from Burnet and Brenguier (2006)

LES profiles shifted downwards by 10 m. LES values scaled to match aircraft obs at +50 m and -100 m.

0 0.2 0.4 0.6 0.8 1!100

!50

0

50

Mixing Fraction

mixing fraction

he

igh

t a

bo

ve

clo

ud

to

p

!l

qt

mean

Figure 33: Profile of mixing fractions for the native and averaged grid.

35

of free atmosphere air

0 0.5 1 1.5 2 2.5 3780

800

820

840

860

880

he

igh

t (m

)

x (km)

zlwc

zmgd

zmix

0 0.5 1 1.5 2 2.5 3!0.5

0

0.5

1

1.5

mix

ing

fra

ctio

n

x (km)

Figure 56: horizontal segement at x=250 for zlwc (red), zmgd (blue), and zmix (black) in height coordinates (top) andmixing fraction coordinates (bottom).

57

Interface heights•mixing top•maximum gradient level•cloud top

!0.2 !0.1 0 0.1 0.2 0.3 0.4 0.5!1

0

1

2

Native Grid

buoyancy (

K)

!0.2 !0.1 0 0.1 0.2 0.3 0.4 0.5!1

0

1

2

Averaged Grid

buoyancy (

K)

!0.2 !0.1 0 0.1 0.2 0.3 0.4 0.5!1

0

1

2

Saturation Adjustment

mixing fraction

buoyancy (

K)

Figure 37: Same as figure 34, except for buoyancy.

39

0 0.2 0.4 0.6 0.8 10

0.2

0.4

0.6

0.8

1x 10

!3 Native Grid

mixing fraction

clo

ud

wa

ter

mix

ing

ra

tio

(kg

/kg

)

0 0.2 0.4 0.6 0.8 10

0.2

0.4

0.6

0.8

1x 10

!3 Averaged Grid

mixing fraction

clo

ud

wa

ter

mix

ing

ra

tio

(kg

/kg

)

Figure 36: Same as figure 34, except for cloud water mixing ratio.

38

0 0.2 0.4 0.6 0.8 10

0.02

0.04

0.06

0.08

0.1

Native Grid

mixing fraction

Su

b!

grid

sca

le T

KE

(kg

*m2/s2)

0 0.2 0.4 0.6 0.8 10

0.02

0.04

0.06

0.08

0.1

Averaged Grid

mixing fraction

Su

b!

grid

sca

le T

KE

(kg

*m2/s2)

Figure 39: Same as figure 34, except for subgrid scale turbulent kinetic energy.

41

0 0.2 0.4 0.6 0.8 1!2

!1.5

!1

!0.5

0

0.5

1

Native Grid

mixing fraction

vert

ical velo

city (

m/s

)

0 0.2 0.4 0.6 0.8 1!2

!1.5

!1

!0.5

0

0.5

1

Averaged Grid

mixing fraction

vert

ical velo

city (

m/s

)

Figure 38: Same as figure 34, except for vertical velocity.

40

EIL properties vs mixing fraction

!0.100.10.20.30.40.50.60.70.80.9!1

!0.5

0

0.5

Native Grid

mixing fraction

vertical velocity (m/s)

!0.100.10.20.30.40.50.60.70.80.9!1

!0.5

0

0.5

Averaged Grid

mixing fraction

vertical velocity (m/s)

Figure48:Sameasfigure44,exceptforverticalvelocity.

49

- 43 -

Figure 5 : Statistics (mean value ± standard deviation) of vertical velocity and potential virtual

temperature, as functions of the mass fraction of adiabatic cloudy air in the mixture : a)

DYCOMS-II case, b) SCMS 10 August case and c) SCMS 5 August case. Vertical dashed

and dot-dashed lines indicate the cloud boundary (!0) and the critical mixing proportion (!ce),

respectively.

b)

c)

a)

Vertical velocity vs mixture fraction

Burnet & Brenguier 2006