Life Cycle of Convective Systems
over Western Colombia
Meiry Sakamoto
Uiversidade de São Paulo, São Paulo, Brazil
Life Cycle of Convective Systems over Western Colombia
([email protected])
Colombia
Life Cycle of Convective Systems over Western Colombia
([email protected])
Convective System (CS) identification
t+∆
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t
t+∆
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Infrared satellite images from CPC/NCEP/NWS for 2003
(4 km horizontal resolution at sub satellite point, 30 min. intervals)
ForTraCC (Forecast and Tracking of active Convective Cells)
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t+∆
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Vila et al, 2008
Temperature threshold of 235K
Minimum cluster of 150 pixels (2,400 km²)
Life cycle ≥ 6 hours
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Moisture Source Identification
Lagrangean Model (Flexpart) applied to ECMWF operational analysis
(1°x1° resolution, 6 hours intervals, 60 vertical levels)
Stohl and James (2004,2005)
Life Cycle of Convective Systems over Western Colombia
([email protected])
Mesoscale Convective Systems Observed During 2003
hour (UTC)
Life Cycle of Convective Systems over Western Colombia
([email protected])
14
Continental MCS
Relative
Frequency (%)
Relative Frequency (%)
12
Oceanic MCS
10
8
6
4
2
0
Jan
Feb
Mar
Apr
May
18
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Aug
Sep
Oct
Nov
Dec
Months of 2003
Continental MCS
16
Oceanic MCS
Life Cycle (hours)
Life Cycle (hours)
14
12
10
8
6
4
2
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Life Cycle of Convective Systems over Western Colombia
([email protected])
100
Continental MCS
West
90
East
70
60
50
40
30
20
10
0
Jan
Feb
Mar
Apr
May
100
Jun
Jul
Aug
Sep
Oct
Nov
Dec Annual
Sep
Oct
Nov
Dec Annual
Oceanic MCS
West
90
East
80
Relative Frequency (%)
Displacement
(July 2003)
Relative Frequency (%)
80
70
60
50
40
30
20
10
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Life Cycle of Convective Systems over Western Colombia
([email protected])
30
Diurnal Cycle
Continental MCS
Relative Frequency (%)
25
Continental MCS
Initial Phase
Mature Phase
Dissipation Phase
20
15
10
5
0
≥00_<03
≥03_<06
≥06_<09
30
Diurnal Cycle
Oceanic MCS
Relative Frequency (%)
25
≥09_<12
≥12_<15
≥15_<18
≥18_<21
≥21_<00
≥15_<18
≥18_<21
≥21_<00
Oceanic
MCS
Period (UTC)
Initial Phase
Mature Phase
Dissipation Phase
20
15
10
5
0
≥00_<03
≥03_<06
≥06_<09
≥09_<12
≥12_<15
Period (UTC)
([email protected])
Life Cycle of Convective Systems over Western Colombia
31Jan, 11.0h, SE
26Feb, 8.5h, NW
18Mar, 11h, SW
23Apr, 14.5h, NW
Moisture Source
to Oceanic MCS
([email protected])
Life Cycle of Convective Systems over Western Colombia
10May, 7.5h, NE
10Jun, 19.5h, NW
20Jul, 16h, SE
23Aug, 14h, SW
Moisture Source
to Oceanic MCS
([email protected])
Life Cycle of Convective Systems over Western Colombia
21Sep, 10h, NW
30Oct, 26h, SW
7Nov, 22h, SW
14Dec, 18h, SW
Moisture Source
to Oceanic MCS
([email protected])
Life Cycle of Convective Systems over Western Colombia
12Jan, 20h, SW
11Feb, 11h, SW
29mar, 11.5h, NW
29Apr, 16h, NW
Moisture Source to
Continental MCS
([email protected])
Life Cycle of Convective Systems over Western Colombia
10May, 28h, NW
26Jun, 9h, SW
18Jul, 27.5h, SW
31Aug, 12h, SW
Moisture Source to
Continental MCS
([email protected])
Life Cycle of Convective Systems over Western Colombia
24Sep, 18.5h, SW
21Oct, 10.5h, NW
16Nov, 10h, SW
26Dec, 21h, SW
Moisture Source to
Continental MCS
Life Cycle of Convective Systems over Western Colombia
([email protected])
Summary
 Continental and oceanic MCS´s are more numerous during boreal summer and autumn.
 Oceanic systems have shorter life cycles than continental ones. In continent, systems generated in May,
June and July present longer life cycle.
 Westward displacement is a trend in continental and oceanic systems, except in January, February and
March.
 Continental systems are mainly generated in the afternoon or early night, their mature phase can happen at
night or early morning. Dissipation happens during all day long.
 Oceanic systems have their genesis and mature phases more frequently during evening and early morning,
and dissipation is observed all day with a peak at afternoon.
 The moisture source to systems initiated in Pacific ocean:
December-May: tropical North Atlantic and Caribbean Sea, and in some events the Chilean Pacific
May-September: Amazonia and Chilean Pacific
October-November: Chilean-Peruvian Pacific and the Caribbean Sea
To continental systems moisture comes from:
December-March: tropical North Atlantic and Caribbean Sea
April-May: Amazonia, the tropical North Atlantic, and the Chilean-Peruvian Pacific
May-July: from the tropical North Atlantic and the Amazon basin
July-October: from Amazonia, the Chilean-Peruvian Pacific, and even from high latitude South America
November: tropical Atlantic, Amazonia and the Peruvian Pacific
Thank You!