mjo is: a convective disturbance that initiates over the tropical indian ocean and propagates...
TRANSCRIPT
![Page 1: MJO is: A convective disturbance that initiates over the tropical Indian Ocean and propagates eastward. MJO “wave” can propagate around the entire tropics](https://reader036.vdocuments.net/reader036/viewer/2022070410/56649ec75503460f94bd41fe/html5/thumbnails/1.jpg)
Hypothesis
Hypo. I: MJO convective envelop
only develops when the moist layer is
deep enough;
Hypo. II: Specific convective
populations at different stages are
essential for MJO initiation;
Hypo. III: The barrier layer, wind- and shear-driven mixing, shallow thermocline, and mixing-layer entrainment all play essential roles in MJO initiation.
“Discharge-Recharge”MJO onset theory
MJO Initiation and Hypothesis
![Page 2: MJO is: A convective disturbance that initiates over the tropical Indian Ocean and propagates eastward. MJO “wave” can propagate around the entire tropics](https://reader036.vdocuments.net/reader036/viewer/2022070410/56649ec75503460f94bd41fe/html5/thumbnails/2.jpg)
Global MJO Phase (WH)
OLR&
850 mb Winds(Nov-Dec-Jan,
1974-2009)
MJO indexPhase 1-8
(Wheeler and Hendon 04)
1
2
3
4
5
6
7
8
Red box(DYNAMO)
![Page 3: MJO is: A convective disturbance that initiates over the tropical Indian Ocean and propagates eastward. MJO “wave” can propagate around the entire tropics](https://reader036.vdocuments.net/reader036/viewer/2022070410/56649ec75503460f94bd41fe/html5/thumbnails/3.jpg)
DYNAMO MJO Definitions
Global Definition
WH 04 (RMM1, RMM2)
Local Definition
Regional Rainfall
Phase 2-3, Indian Ocean Day 0: Most active
![Page 4: MJO is: A convective disturbance that initiates over the tropical Indian Ocean and propagates eastward. MJO “wave” can propagate around the entire tropics](https://reader036.vdocuments.net/reader036/viewer/2022070410/56649ec75503460f94bd41fe/html5/thumbnails/4.jpg)
Atmospheric Moisture Profiles—Revelle sounding data
1. Driest Atmos:
Phase 5-6
2. Lower-level
Moistening:
Phase 7-8
3. Upper-level
Moistening:
Phase 1
4. Upper Drying:
Phase 4
![Page 5: MJO is: A convective disturbance that initiates over the tropical Indian Ocean and propagates eastward. MJO “wave” can propagate around the entire tropics](https://reader036.vdocuments.net/reader036/viewer/2022070410/56649ec75503460f94bd41fe/html5/thumbnails/5.jpg)
Overview: Environ., Precip., and Lightning
How does convective population change?Phase 1 peak lightning, peak SST, intense convection
1. In phase:
RH, Rainfall,
Strat. Rain.
Large s/f
fraction
2. In phase:
SST, Lightning,
CAPE.
![Page 6: MJO is: A convective disturbance that initiates over the tropical Indian Ocean and propagates eastward. MJO “wave” can propagate around the entire tropics](https://reader036.vdocuments.net/reader036/viewer/2022070410/56649ec75503460f94bd41fe/html5/thumbnails/6.jpg)
Convective Feature Database (TOGA Radar)
20-dBZ radar clusters
Max Height(20, 30, 40
dBZ)
Conv./Strat.Info.
Feature SizeInfo.
LightningInfo.
Rain RateInfo.
![Page 7: MJO is: A convective disturbance that initiates over the tropical Indian Ocean and propagates eastward. MJO “wave” can propagate around the entire tropics](https://reader036.vdocuments.net/reader036/viewer/2022070410/56649ec75503460f94bd41fe/html5/thumbnails/7.jpg)
Overall Statistics of Convective Population
DYNAMO vs. TRMM, and TOGA-COARE
MIT data?
![Page 8: MJO is: A convective disturbance that initiates over the tropical Indian Ocean and propagates eastward. MJO “wave” can propagate around the entire tropics](https://reader036.vdocuments.net/reader036/viewer/2022070410/56649ec75503460f94bd41fe/html5/thumbnails/8.jpg)
Convective (feature) Population Small (< 200), Medium (200-1000), MCS (> 1000 km2)
Shallow (< 5 km), Middle (5-8 km), Deep (> 8 km)
“Similar Pattern in
Oct and Nov.MJO Cycle”
![Page 9: MJO is: A convective disturbance that initiates over the tropical Indian Ocean and propagates eastward. MJO “wave” can propagate around the entire tropics](https://reader036.vdocuments.net/reader036/viewer/2022070410/56649ec75503460f94bd41fe/html5/thumbnails/9.jpg)
Horizontal Precipitating Area
![Page 10: MJO is: A convective disturbance that initiates over the tropical Indian Ocean and propagates eastward. MJO “wave” can propagate around the entire tropics](https://reader036.vdocuments.net/reader036/viewer/2022070410/56649ec75503460f94bd41fe/html5/thumbnails/10.jpg)
Areal Mean Rain Amount
![Page 11: MJO is: A convective disturbance that initiates over the tropical Indian Ocean and propagates eastward. MJO “wave” can propagate around the entire tropics](https://reader036.vdocuments.net/reader036/viewer/2022070410/56649ec75503460f94bd41fe/html5/thumbnails/11.jpg)
Typical Case in Phase 1 to 4
P 1 P 2
P 3 P 4
![Page 12: MJO is: A convective disturbance that initiates over the tropical Indian Ocean and propagates eastward. MJO “wave” can propagate around the entire tropics](https://reader036.vdocuments.net/reader036/viewer/2022070410/56649ec75503460f94bd41fe/html5/thumbnails/12.jpg)
Typical Case in Phase 5 to 8
P 5-6
P 7 P 8
![Page 13: MJO is: A convective disturbance that initiates over the tropical Indian Ocean and propagates eastward. MJO “wave” can propagate around the entire tropics](https://reader036.vdocuments.net/reader036/viewer/2022070410/56649ec75503460f94bd41fe/html5/thumbnails/13.jpg)
Daily Evolution: Convective Population
1. In phase:
RH, Rainrate,
Strat. Rain.
2. In phase:
SST, Lightning,
CAPE.
Role of Aerosols?