Multisensor Investigation of Deep

Convection

AGU, San Francisco, 5 December 2012

Robert A. Houze, Jr., & Jian Yuan

University of Washington

Mesoscale Convective Systems“MCSs”

Large areasof cold top

Example outbreak of MCSs

1458GMT 13 May 2004

ConvectivePrecipitation

StratiformPrecipitation

Radar echoes showing the precipitation in the 3 MCSs

How do MCS properties vary globally?

Details learned from field projects

Houze et al. 1989

Basic components

Houze et al. 1989

Anvil Anvil

Raining core

Cold top

The 3 basic components can be determined from A-Train!

12

3

Combining cloud top and raining core properties to determine MCS existence

260KClosedcontour Rain

Heavy rain

Identify High Cloud Systems (HCSs)

ConnectedMCSs

SeparatedMCS

Which HCSs are MCSs?

Yuan and Houze 2010

PDF of rain amount as a function of raining core properties

Size of raining core

Min

TB

11 o

ver r

aini

ng c

ore

2000 km2

220°K

56% all tropical rain

Using these values for “MCS” criteria

Yuan and Houze 2010

MCSs Over the Whole TropicsSmallest 25% (<12,000 km2)

Largest 25% (>40,000 km2)

“Superclusters”

Yuan and Houze 2010

MODIS/AMSR-E identifies cold top

locates the raining coreremainder is anvil

Anvil Anvil

Raining core

Cold top

Frequency of MCS anvils over tropics

Yuan and Houze 2010

The Anvil Problem

Extensively studied

Need to understand how anvil is related to the

raining region

Mesoscale Convective System

CloudSat applied to MCS anvils

Statistics of anvil width & thickness seen by CloudSat

Yuan and Houze 2010

Africa Indian Ocean

Internal structure of MCS anvils

CVCV

CVCV

Indian Ocean Anvils

Yuan, Houze, and Heymsfield 2011

Africa Indian Ocean

Internal structure of MCS anvils

Future Work

Multisensor identification of MCSs makes it possible to answer important questions about the global variability of MCSs

• Thin-cloud extent of the MCS anvils? CALIPSO

• Environments of MCSs? Reanalysis, AIRS

• Aerosol environments? CALIPSO, MODIS

• Electrical properties? WWLLN, other networks

Summary

Future studies • CALIPSO—thin cloud extent of MCS anvils• MODIS & CALIPSO—aerosol environment of

MCSs• WWLLN—electrification of MCSs

MODIS Tb11, AMSR-E, & CloudSat

• mapping of Mesoscale Convective Systems and their anvil clouds

End

This research was supported by NASA grants NNX10AH70G, NNX10AM28G,

and NSF grant AGS1144105

End

This research was supported by NASA grants NNX10AH70G, NNX10AM28G,

and NSF grant AGS1144105

Indian Ocean MCSs Contribution to Rainfall by phase of the Madden-Julian Oscillation

Yuan and Houze 2012

Connected MCSs

Connected MCSs

Other high cloud systems

convective rain stratiform rain

graupel

snow

Conceptual model of anvil microphysics

Cetrone and Houze 2011