1. AGU Annual Meeting, San Francisco, 11 December 2013

2. The MJO scale ~30-60 days “Active Period” ~1-3 weeks Wheeler & Hendon 2004 “Active Period” ~1-3 weeks

3. The convective scales

4. Examples from DYNAMO Examples Broad stratiform Deep cores Shallow isolated Wide cores From Powell and Houze 2013 ~½-1 h ~5-10 h

5. TRMM radar shows how the scale of individual convective entities vary with phase of the MJO Barnes and Houze 2013 Shallow Isolated Echoes Deep Convective Cores Broad Stratiform Regions Wide Convective Cores Active conditions Suppressed conditions

6. ConvectiveStratiform Kingsmill and Houze 1999 ~50 aircraft surveys in TOGA COARE x

7. Kingsmill and Houze 1999 ~50 aircraft surveys in TOGA COARE x ConvectiveStratiform

8. Wide convective elements and broad stratiform regions are like Moncrieff’s mesoscale layer model of deep tropical convection… Moncrieff 1992 …mesoscale adjustment to shear and thermodynamic stratification 100-200 km

9. DYNAMO radar data show microphysical stratification ~constant for both convective and stratiform entities Melting snow Graupel Dry snow Small ice Convective Stratiform Convective Stratiform Convective Stratiform % of observations October NovemberDecember Rowe & Houze 2013 Melting snow Graupel Dry snow Small ice

10. Intermediate scales Smaller than MJO Larger than convective entities

11. S-PolKa Radar Rainfall at Addu Atoll in DYNAMO Powell and Houze 2013 OLR

12. Rain seen by the S-PolKa radar in DYNAMO Zuluaga and Houze 2013 October Active Period November Active Period December Active Period Occurred in “episodes” separated by ~2-7 days Filter and composite

13. Zuluaga and Houze 2013 Composite large-scale divergence and vertical motion during 2-day rainfall episodes Divergence

14. Variation of the DYNAMO radar echo population relative to a precpitation episode Zuluaga and Houze 2013 Composite of all 2-day rainfall episodes

15. The largest scale

16. Vertical structure of the MJO Moncrieff 2004 ~10,000 km ~30-60 days

17. Vertical structure of the MJO Moncrieff 2004 ~10,000 km ~30-60 days Coupling with the changeable convective population

18. Vertical structure of the MJO Moncrieff 2004 ~10,000 km ~30-60 days Kelvin wave Rossby wave 2-7 day waves Cloud- humidity feedback Mid-latitude interaction

19. Summary Convection in the MJO has multiple important scales Shallow isolated Deep cores Wide cores Broad stratiform rain areas How does convection accommodate systematically to Intermediate scale waves, which account for most of the rainfall Larger scale of the MJO itself

20. End This research was supported by NASA grants NNX10AH70G, NNX13AQ37G and NNX13AG71G NSF grant AGS-1059611 DOE grant DE-SC0008452

21. Extra Slides

22. …Barnes talk & upcoming paper Convective Convective entities DYNAMO radar data composited relative to the mesoscale airflow

23. Convective Convective entities 0°C Stratiform entities …Barnes talk & upcoming paper

24. Stretched Building Block Hypothesis Mapes et al. 2006 Large-scale wave structure at the same times Cloud population at three different times

26. Vertical structure of the MJO Moncrieff 2004 ~10,000 km

27. Upper-level eastward propagating Kelvin waves? …Scott Powell’s poster u’ at 150 mb DYNAMO