1 / 47

The Convective Cloud Population during the Buildup of the Madden-Julian Oscillation

The Convective Cloud Population during the Buildup of the Madden-Julian Oscillation. R. Houze, S. Brodzik, J. Yuan University of Washington. AGU Fall Meeting, San Francisco, 7 December 2011. The Convective Cloud Population during the Buildup of the Madden-Julian Oscillation.

minnie
Download Presentation

The Convective Cloud Population during the Buildup of the Madden-Julian Oscillation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The Convective Cloud Population during the Buildup of the Madden-Julian Oscillation R. Houze, S. Brodzik, J. YuanUniversity of Washington AGU Fall Meeting, San Francisco, 7 December 2011

  2. The Convective Cloud Population during the Buildup of the Madden-Julian Oscillation Three perspectives: TRMM Still going on! A-Train DYNAMO

  3. The MJO

  4. Indian Ocean 1 Phases of the MJO 2 3 Wheeler and Hendon 2004 4 5 6 7 8 DYNAMO

  5. TRMM

  6. Frequency of radar echo in “broad stratiform regions” of MCSs Phase 1 Phase 5 Phase 3 Phase 7

  7. Frequency of radar echo in “deep convective cores” Phase 1 Phase 5 Phase 3 Phase 7

  8. Frequency of “shallow isolated” radar echoes (anomaly) Phase 1 Phase 5 Phase 3 Phase 7

  9. Variation of Echo Category with MJO Phase

  10. A-Train

  11. Mesoscale Convective Systems (MCSs) have cold tops and large intense raining cores Both raining and anvil components are identified using A-Train instruments

  12. a) Cloud coverage b) Contribution to precipitation “Connected MCSs” “Separated MCSs” CMCSs SMCSs HCSs excl.MCSs non-HCSs Percentage % Other High CloudSystems Non-high-cloudSystems

  13. DYNAMO

  14. Cloud Structures (NCAR S-PolKa radar)

  15. Suppressed phase: Lines of non-precipitating clouds

  16. Suppressed phase: Clouds at cold pool boundaries

  17. Suppressed phase: Clouds at cold pool boundaries

  18. Small cumulonimbus small ice large non-melting ice graupel 8 km melting snow 4 km heavy rain

  19. Small, weakstratiform area

  20. Active phase: Large mesoscale system Stratiform Convective

  21. Robust melting layerinLarge MCS 10 km 5 km

  22. Convection feeding into a large MCS

  23. Shear

  24. Low-level westerly component, upper-level easterly component NE SW NE SW

  25. Biggest MCS of first active phase: weak unidirectional shear

  26. Larger-than-mesoscale Organization

  27. Giant Rings of Convection

  28. Westerly Surges

  29. Conclusions • Shallow isolated clouds present all the time • Stratiform regions have the biggest variation from suppressed to active phases • SF regions are associated with the largest MCSs • SF regions can be extremely robust with strong melting layers with melting graupel as well as snow • Shear seems to inhibit stratiform region formation • Convection has larger-than-mesoscale organization: rings, westerly bursts,….

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

  31. Extras

  32. Identify each contiguous 3D echo objectseen by TRMM PR Convective component Stratiform component Extreme characteristic Contiguous 3D volume ofconvective echo > 30 dBZ Extreme characteristic Contiguous stratiform echowith horizontal area > 50 000 km2 “Broad stratiform region” Top height > 8 km “Deep convective core” Horizontal area > 800 km2 “Wide convective core” Categories of radar echoes seen by TRMM

  33. MODIS TB11 + AMSR-E (Yuan and Houze 2010) combined to find“cold centers” & “raining areas” Locate 1st closed contour Use 260 K threshold Associate pixels with nearest cold center Use 1 mm/h threshold for rain rate Use 6 mm/h threshold for heavy rain

  34. 1 2 3 4 5 6 7 8 Phase

  35. 200 600 Mixing ratio anomaly 1000 Pressure (hPa) Phases 1,8 Phases 2,3 Phases 4,5 Phases 6,7 200 600 1000 DYNAMO 50 E 100 E 150 E 200 E

  36. Descent of easterlies

More Related