1 THE MADDEN-JULIAN OSCILLATION AND CALIFORNIA RAINFALL Charles Jones University of California Santa Barbara

2 The Madden-Julian Oscillation Madden and Julian (1972)

3

4 * Significant case-to-case variability

5  Modulate the variability of the monsoons in Asia-Australia, Africa and Americas  Teleconnections with extratropics in both hemispheres  Modulate thermocline variability in the tropical Pacific Ocean  Influence on forecast skills in the tropics and extratropics

6 Outgoing Longwave Radiation Climatology TCTC TSTS T C < T S

7 MJO  Pentads of OLR (winter) Filtered days anomalies  EOF of OLR anomalies  Active MJO: amplitudes of PC1 and PC2

8 The Life Cycle of the MJO: Convective Activity Jones (2000) Enhanced Convection Suppressed Convection OLR Data are filtered in time (20-90 days) and composites of OLR anomalies are made Time

9 Zonal (U) wind component (850 hPa) is filtered in time (20-90 days) and composites of anomalies are made Westerly anomalies Easterly anomalies Enhanced Convection Time