Transcript 160303NewportNews_CloudSatSciTeam_Virts.ppt

Intraseasonal Variability of
Mesoscale Convective Systems
over the South Asian Monsoon Region
Katrina Virts and Robert A. Houze, Jr.
University of Washington
Identifying MCSs using A-Train data
Yuan and Houze (2010)
Data sources
• MCS database (2007-2010)
– Small separated MCSs
– Large separated MCSs
– Connected MCSs
• CloudSat
– Vertical structure of precipitating and anvil regions
• World-Wide Lightning Location Network
– Monitors very low frequency (VLF) waves
– MCS lightning frequency: lightning in one-hour window
within MCS cloudy area
• ERA-Interim reanalysis
Meghalaya
Plateau
NE Himalayan
notch
Bay of Bengal
30-60 day 925-hPa wind, height anomalies
Based on BSISO1 index by Lee et al. (2013)
30-60 day 925-hPa wind, height anomalies
Based on BSISO1 index by Lee et al. (2013)
“Active”
CMCS
Large SMCS
Bay of Bengal
925-hPa anomalies
Bay of Bengal
Bay of Bengal
Bay of Bengal
Meghalaya Plateau
850-hPa anomalies
Meghalaya
Plateau
Meghalaya
Plateau
NE Himalayan notch
850-hPa anomalies
CAPE anomalies
Conclusions
• MCS occurrence and characteristics exhibit
intraseasonal variations during the South Asian
monsoon
• Locally rainy period: large and connected MCSs with
mature stratiform areas; decreased lightning
production
• Locally dry period: stronger convective signatures
and more lightning production
• Regional dependence of monsoon effect on MCSs
This work was funded by NASA grants NNX13AQ37G, NNX13AG71G, and NNX16AD75G