1. Hongyan Zhu, Harry Hendon and Rachel Stratton
Vertical Moisture Budget Associated with MJO Simulation in ACCESS Model
Hongyan Zhu, Harry Hendon and Rachel Stratton

2. UM GA2.0 model physics with increased entrainment rates.
Model settings:
UM GA2.0 model physics with increased entrainment rates.
Integration periods: From 1.Jan Dec. 2010
SST and SeaIce data: valid 26 December 1990 through 5 January 2011

3. Lag correlations , Indian Ocean for boreal winter (November-April), U850
OLR
OLR
U850

5. Vertical moisture budget relative to the intense rainfall events
(60E-180E, 20S-Equator)
Total moisture tendency
Moisture Anomaly
recharge
discharge m m

6. Vertical moisture budget relative to the intense rainfall
(60E-180E, 20S-Equator) m m
recharge
discharge
recharge
discharge
Large Scale Moisture advection
Moisture tendency from convection

7. Vertical moisture budget relative to the intense rainfall events
(60E-180E, 20S-Equator) m m
recharge
discharge
recharge
discharge
Horizontal Moisture advection
Vertical Moisture advection

8. SH
Model 850 wind anomalies and specific humidity at lags of -3 days relative to the intense rainfall event.
The domain center is the grids where the intense rainfall event occur.
Poleward
Grid points

9. SH
Model 850 wind anomalies and specific humidity at lags of + 3 days relative to the intense rainfall event.
The domain center is the grids where the intense rainfall event occur.
Grid Point
Poleward
Grid Point

10. The solution of the forced shallow-water equations for heating has a maximum north of equator. (Adrian Gill, Atmosphere-Ocean Dynamics)

11. Expt. 2, With modified melting levels
Convective heating tendencies shows that the UM has a large cooling spike at the freezing level due to all the snow in the downdraught being melted in the layer where the environmental temperature reaches the freezing level.
Spreading the melting of snow in the downdraught between temperatures from the freezing level to 10K above the freezing level. This change allows a mix of snow and rain between the freezing level and 10K above this with the proportion of rain increasing linearly from zero at the freezing level to one at the freezing level plus 10K.

12. Temperature anomaly from convection scheme
(60E-180E, 20S-Equator)
Control
Expt. With modified melting levels

14. Difference between the control experiment and the experiment with changed melting levels.
Blue colour means that rainfall rate increases in the new experiment.
Red colour means that rainfall rate decreases in the new experiment.

15. RH difference between the control experiment and the experiment with changed melting levels (averaged between 10S and 0).

16. MJO Multi-scale metrics: Coherence**2 and phase (OLR and U850)
Expt. 1
Expt. 2

17. Conclusion and Discussion
Total moisture tendency is asymmetric relative to the maximum precipitation, corresponding to the recharge and discharge process of organized convection in the Tropics.
Instead of moistening by shallow convection, model moisture charge and discharge is consistent with the large-scale horizontal advection of moisture.
Horizontal moisture convergence helps to the recharge of moisture before the intense rainfall events.
The moisture advection between the equator and poleward latitudes after the rainfall maximum helps to discharge of moisture and stabilize the atmosphere.
The change for the melting level has an influence on model MJO simulation.