Regional, Seasonal and Diurnal Variations

of Convection in the Asian Monsoon Region

Ulrike Romatschke,Robert Houze, Socorro Medina

University of Washington, Seattle

Region of Study

Inhalt• Einleitung

Daten

• Regional Variations

Vergleich mit Houze et al.

• Seasonal Variations

Premonsoon – Monsoon

• Diurnal Variations

Zusammenhang mit Topographie

• Zusammenfassung und Ausblick

Daten

• TRMM Precipitation Radar (PR), Version 6• Products

2A23: Radar Rain Characteristics

2A25: Radar Rainfall Rate and Profile

• Monsoon Season: Juni - September

1999-2001

2004-2006

• Premonsoon Season: Mai

1999-2006

Definitionen• Deep Intense Convective Cores

40 dBZ echo > 10 km in hight

• Wide Intense Convective Cores

40 dBZ echo area > 1,000 km²

• Broad Stratiform Echos

area > 50,000 km²

20

16

12

8

4

00 42.5 85

Hei

ght

[km

]

Distance [km]24

22

20

Latit

ude

84 86 88 90 Longitude

15

20

Latit

ude

90 95Longitude

[dBZ]

Ziele

• Vergleich mit Houze et al. (2007)• Erweiterungen

Daten

Region

Premonsoon Season

• Diurnal Cycle• Erkennen von besonders aktiven Regionen

Inhalt• Einleitung

Daten

• Regional Variations

Vergleich mit Houze et al.

• Seasonal Variations

Premonsoon – Monsoon

• Diurnal Variations

Zusammenhang mit Topographie

• Zusammenfassung und Ausblick

Comparison

Deep Intense Convective Cores

2002-2003

1999-2001/2004-2006

Large Scale Flow Patterns during Monsoon

1000 mb 700 mb

Terrain [km]

40

30

20

10

60 70 80 90 100/60 70 80 90 100

Comparison

Wide Intense Convective Cores

2002-2003

1999-2001/2004-2006

Comparison

Broad Stratiform Systems

2002-2003

1999-2001/2004-2006

Inhalt• Einleitung

Daten

• Regional Variations

Vergleich mit Houze et al.

• Seasonal Variations

Premonsoon – Monsoon

• Diurnal Variations

Zusammenhang mit Topographie

• Zusammenfassung und Ausblick

Deep Intense Convective Cores

Premonsoon Monsoon

The Indian Dry-Line

Weston (1971)

1000

mb

700

mb

Sur

face

p [

mb]

and

v

50

0 m

b v

The Indian Dry-Line200 mb 700 mb 1000 mb

Mon

soon

P

rem

onso

on

Wide Intense Convective Cores

Premonsoon Monsoon

Wide vs. Deep Intense Convective Cores

Premonsoon Premonsoon

Wide vs. Deep Intense Convective Cores

Monsoon Monsoon

Wide vs. Deep Intense Convective Cores

MonsoonGanges Delta

Broad Stratiform Systems

Premonsoon Monsoon

Broad Stratiform Systems

Rain Climatology Monsoon

Xie et al. (2006)

Inhalt• Einleitung

Daten

• Regional Variations

Vergleich mit Houze et al.

• Seasonal Variations

Premonsoon – Monsoon

• Diurnal Variations

Zusammenhang mit Topographie

• Zusammenfassung und Ausblick

Diurnal Cycle, Monsoon

Diurnal Cycle

Diurnal Cycle

Diurnal Cycle, Monsoon

Diurnal CycleDeep Intense Convective Cores

Monsoon

Diurnal CycleDeep Intense Convective Cores

Monsoon

Diurnal CycleDeep Intense Convective Cores

Monsoon

Diurnal CycleDeep Intense Convective Cores

Monsoon

Diurnal CycleDeep Intense Convective Cores

Premonsoon

Diurnal CycleDeep Intense Convective Cores

Premonsoon

Xie et al. (2006)

Surface p [mb] and v

Weston (1971)

Diurnal Cycle, Deep Intense Convective Cores, Premonsoon

Zuidema (2002)

Mean percent high cloudiness

Cloud Top < 210 K

May – September 1999

Diurnal Cycle, Monsoon

Diurnal Cycle, MonsoonWide Intense Convective Cores

1999-2001 vs. 2004-2006

1999-2001 2004-2006

Diurnal CycleWide Intense Convective Cores

Monsoon

Diurnal CycleWide Intense Convective Cores

Monsoon

Xie et al. (2006)

Diurnal CycleWide Intense Convective Cores

Premonsoon - Monsoon

Diurnal CycleWide Intense Convective Cores

Premonsoon

Diurnal Cycle, Monsoon

Diurnal Cycle, Monsoon

Diurnal CycleBroad Stratiform Systems

Monsoon

Diurnal CycleBroad Stratiform Systems

Monsoon

Diurnal CycleBroad Stratiform Systems

Monsoon

Diurnal CycleBroad Stratiform Systems

Monsoon

Williams and Houze (1987)

Inhalt• Einleitung

Daten

• Regional Variations

Vergleich mit Houze et al.

• Seasonal Variations

Premonsoon – Monsoon

• Diurnal Variations

Zusammenhang mit Topographie

• Zusammenfassung und Ausblick

Zusammenfassung• Größerer Datensatz scheint Houze et al. (2007) zu

bestätigen.

• Premonsoon – Monsoon• Verschiebung der Region in welcher die meisten Deep und Wide Intense Convective Cores auftreten.• Mehr Wide Intense Convective Cores und Broad Stratiform Systems über dem Meer in Monsoon Season.

• Diurnal Cycle• Maximum der Deep Intense Convective Cores am Nachmittag.• Nachmittag- und Nachtmaxima der Wide Intense Convective Cores.• Abendminimum der Broad Stratiform Systems.

• Rain Climatology vergleichbar• mit Broad Stratiform Systems über dem Meer.• mit Wide Intense Convective Cores am Fuß des Himalaya.• nicht mit Deep Intense Convective Cores.

Ausblick

• 2002/2003 Version 6 data.

• Statistiken für weitere Variablen.

• Spezielle Regionen• physikalischer Hintergrund

• Felder (z.B. Wind)

• Satellitendaten

Variables

• Orbitnumber• Date• Time• Number of pixels 3D• Number of pixels 2D• Latitude• Longitude• Height• Longest horizontal dimension• Height of terrain• Area

• Number of convective pixels• Number of stratiform pixels • Convective, stratiform, total

• rain rate

• volumetric rain rate

• rain fraction

• area fraction

Ausblick

• 2002/2003 Version 6 data.

• Statistiken für weitere Variablen.

• Spezielle Regionen• physikalischer Hintergrund

• Felder (z.B. Wind)

• Satellitendaten

Ausblick