The Convective Cloud Population of the Madden-Julian Oscillation: Early Results from DYNAMO

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The Convective Cloud Population of the Madden-Julian Oscillation: Early Results from DYNAMO. R. Houze D. Hence, S. Brodzik , K. Rasmussen, S.Powell , H. Barnes, B. Dolan, K. Chakravarty , C. Burleyson , Z. Li, S. Ellis, T. Weckwerth , J. Vivekanandan , J. Hubbert , W.-C. Lee. - PowerPoint PPT Presentation

Text of The Convective Cloud Population of the Madden-Julian Oscillation: Early Results from DYNAMO

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The Convective Cloud Population of the Madden-Julian Oscillation: Early Results from DYNAMOInt. Conf. on Opportunities and Challenges in Monsoon Prediction in a Changing ClimateGolden Jubilee of the Indian Institute of Tropical Meteorology, Pune, India, 23 February, 2012R. Houze D. Hence, S. Brodzik, K. Rasmussen, S.Powell, H. Barnes, B. Dolan, K. Chakravarty, C. Burleyson, Z. Li, S. Ellis, T. Weckwerth, J. Vivekanandan, J. Hubbert, W.-C. Lee

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MJO Initiation area

Addu AtollFive radars on Addu Atoll

Radar experiment goal Characteristics and evolution of the MJO cloud population in the region where the disturbance builds upAddu Atoll

SKaNCAR S-PolKaRadar

Supp.Supp.Supp.ActiveActiveActiveLullRain over area scanned by S-PolKa

Suppressed conditionechoes

Supp.Supp.Supp.ActiveActiveActiveLull

Suppressed phases:

Lines of non-precipitating clouds

Suppressed phases: The worm echo

Slightly active moist layer

Clouds building at cold pool boundaries

Slightly active moist layer

Clouds building at cold pool boundaries

Cold pool boundaries seen in differential reflectivity (ZDR)

Birds?Dragonflies????

Birds caught on camera

graupelsmall icelarge non-melting iceheavyrainmeltingiceModerate cumulonimbus begin to grow upscale Doppler velocityHydrometeor type

Supp.Supp.Supp.ActiveActiveActiveLull

October 16

Refl.RainConv.Strat.October 16

5 km 10 km Intense melting layer

melting snowgraupel50 dBZ!

Active phase few days later

Convection feeding into a large MCS

Biggest MCS of first active phase: weak unidirectional shear

Supp.Supp.Supp.ActiveActiveActiveLull

Squall line in late active phase westerlies

Supp.Supp.Supp.ActiveActiveActiveLull

Suppressed condition clouds28

Supp.Supp.Supp.ActiveActiveActiveLull

Supp.Supp.Supp.ActiveActiveActiveLull

Westerly Surges

November

OctoberLarger than mesoscale organization of deep convection

Supp.Supp.Supp.ActiveActiveActiveLull

Long arc lineWesterlies moist up to 500 mb, dry aboe37

Long arc linesegment on radar

Squall linein the strong westerlies

Weak stratiform in the strong westerlies Stratiform Rain Fraction

S-PolKa S-band Stratiform Rain Fraction

Supp.Supp.Supp.ActiveActiveActiveLull

The most robust squall line in the strong westerlieshas only moderate stratiformMomentum transport

Supp.Supp.Supp.ActiveActiveActiveLull

Summary of MJO cloud population characteristics & evolution seen by the S-PolKa radarHumidity gradient layers monitored & measuredCloud lines dominate in highly suppressed periodCold pools are first stage of convective population Graupel & other ice lofted & input into stratiform regionsConvection enhanced inside stratiform regionsMCS development strongest in weak shearShear inhibits stratiform region formation Westerlies organize convection on larger than mesoscaleSquall lines form in westerlies at back of active zoneSquall lines transport momemtum downward

EndThis research is supported by NSF grant ATM AGS-1059611, DOE grant DE-SC0001164/ER-64752, and NASA grants NNX10AM28G and NNX10AH70G

EndThis research is supported by NSF grant ATM AGS-1059611, DOE grant DE-SC0001164/ER-64752, and NASA grants NNX10AM28G and NNX10AH70G