“CONVECTIVE CLOUDS SPACE AND TIME

ORGANIZATION: THE REGIONAL

DIFFERENCES”

Wagner Flauber Araújo Lima

and

Luiz Augusto Toledo Machado

CHUVA International Workshop

CHUVA International Workshop

Objective

Investigate the space and time organization ofthe convective clouds and rain cells during theCHUVA campaigns.

CHUVA International Workshop

Methodology Fortracc Satellite set up

Minimum Size: 20 pixels = 320km²;

Field : Brightness Temperature Ch4 (K);

Spatial resolution = 4km;

Threshold BT = 235 K ;

Sites

Fortaleza;

Belém;

Vale;

Santa Maria;

Average Direction of Propagation and Speed of Convective Systems

FORTRACC SATELLITE

Frequencies of Convective Systems in (4 x 4) km area during CHUVA Campaigns

FORTRACC SATELLITE

Frequencies of Convective Systems in (4 x 4) km area during CHUVA-VALE Campaign

FORTRACC SATELLITE

Average Direction of Propagation and Speed of CS during CHUVA-VALE Campaign

FORTRACC SATELLITE

Histogram Size of the Convective System during CHUVA Campaigns

FORTRACC SATELLITE

0%

5%

10%

15%

20%

25%

30%

11 16 22 32 45 63 89 126 178 251 355 501 708 1000

Fre

qu

en

cy (%

)

Convective System Radius (km)

Histogram Size of the CS for CHUVA

Fortaleza Belém Vale Santa Maria

Histogram Life Cycle Duration of the Convective System during CHUVA Campaigns

FORTRACC SATELLITE

0%

2%

4%

6%

8%

10%

12%

14%

0.75 1.50 2.25 3.00 3.75 4.50 5.25 6.00 6.75 7.50

Fre

qu

en

cy (

%)

Life Cycle Duration (hours)

Histogram Life Cycle Duration of the CS in Site CHUVA

Fortaleza Belém Vale Santa Maria

CHUVA International Workshop

Conclusions MCSs in Santa Maria are faster than any other region;

The frequency of occurrence are normally associated with orography

or on the coast as in Fortaleza.

Size distribution for all regions are very close, Santa Maria presents

the larger , followed by Belém.;

The Life Time durations are also very close among all regions.

Further investigations with radar will give a better understand of the

physical processes associated to the regions.

CHUVA International Workshop

Studies Underway

Space-Time organization of the rain cells- XPOL Radar and

FORTRACC;

Reflectivity profiles as function of the Life Cycle – Regional differences;

0

2

4

6

8

10

12

14

16

18

20

0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0

Centróides Convectivo

G1

G2

G3

G4

G5

0

1

2

3

4

5

6

7

8

9

10

0.0 5.0 10.0 15.0 20.0 25.0

Centróides Nuvens Quentes

G1

G2

G3

0

2

4

6

8

10

12

14

16

18

20

0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0

Centróides Banda Brilhante

G1

G2

G3

G4

G5

Radar Banda-X :

Zdr;

R(dBZ);

Kdp;

Fortracc –Radar :

Cappi in 2km;

Threshold : Dbz > 1;

Size > 100 pixels ( 4 km²);

CHUVA International Workshop

Next Steps MCS Life cycle and convective cloud cover and theirs relations to the

dynamics and thermodynics properties (moisture convergene, upper level

divergence, CAPE, CINE, etc.). The regional differences.

Parameter;

CAPE;

CINE;

Div. Humidity ;

Div. Wind;

Variables;

Rain;

Clouds Cover;