Madden–Julian Oscillation
E64496
The Madden–Julian Oscillation is a large-scale tropical atmospheric pattern characterized by eastward-moving pulses of enhanced and suppressed rainfall that strongly influence global weather and climate variability on intraseasonal timescales.
Observed surface forms (2)
| Surface form | Occurrences |
|---|---|
| MJO | 1 |
| Walker circulation | 1 |
Statements (62)
| Predicate | Object |
|---|---|
| instanceOf |
atmospheric oscillation
ⓘ
climate variability mode ⓘ tropical intraseasonal oscillation ⓘ |
| affects |
onset of the Australian monsoon
ⓘ
onset of the South Asian monsoon ⓘ tropical cyclone genesis in the Atlantic ⓘ tropical cyclone genesis in the Indian Ocean ⓘ tropical cyclone genesis in the western Pacific ⓘ |
| affectsRegion |
global tropics
ⓘ
midlatitudes ⓘ subtropics ⓘ |
| alsoKnownAs |
Madden–Julian Oscillation
ⓘ
surface form:
MJO
|
| characterizedBy |
eastward-propagating regions of enhanced convection
ⓘ
eastward-propagating regions of suppressed convection ⓘ enhanced and suppressed tropical rainfall anomalies ⓘ large-scale circulation anomalies in the tropics ⓘ |
| discoveredBy |
Paul R. Julian
NERFINISHED
ⓘ
Roland A. Madden NERFINISHED ⓘ |
| firstDescribedInPublicationYear | 1971 ⓘ |
| governingProcess | coupling between tropical convection and large-scale circulation ⓘ |
| hasIndex |
RMM1
ⓘ
RMM1 ⓘ
surface form:
RMM2
Real-time Multivariate MJO index ⓘ |
| hasPhase |
active convective phase
ⓘ
multiple longitudinal phases used in indices ⓘ suppressed convective phase ⓘ |
| hasSpatialScale |
10,000 km or more
ⓘ
planetary scale ⓘ |
| hasTypicalPeriod |
30 to 60 days
ⓘ
30 to 90 days ⓘ |
| influences |
ENSO-related variability
ⓘ
atmospheric rivers ⓘ extreme precipitation events ⓘ global weather patterns ⓘ intraseasonal climate variability ⓘ jet stream variability ⓘ monsoon variability ⓘ temperature anomalies in extratropics ⓘ tropical cyclone activity ⓘ tropical rainfall variability ⓘ |
| measuredBy |
Outgoing Longwave Radiation anomalies
ⓘ
zonal wind anomalies at 200 hPa ⓘ zonal wind anomalies at 850 hPa ⓘ |
| modulates |
stratosphere–troposphere coupling
ⓘ
surface fluxes of heat and moisture ⓘ upper-ocean mixed layer variability ⓘ |
| namedAfter |
Paul R. Julian
NERFINISHED
ⓘ
Roland A. Madden NERFINISHED ⓘ |
| playsRoleIn |
extended-range weather forecasting
ⓘ
subseasonal to seasonal prediction ⓘ |
| primaryRegion |
tropical Indian Ocean
ⓘ
tropical western Pacific Ocean ⓘ |
| propagationDirection | eastward ⓘ |
| relatedTo |
Kelvin waves
ⓘ
Rossby waves ⓘ convectively coupled equatorial waves ⓘ |
| timeScale |
30–90 day timescale
ⓘ
intraseasonal ⓘ |
| typicalConvectionDecayRegion | central to eastern Pacific ⓘ |
| typicalConvectionOrigin |
Southwest Indian Ocean
ⓘ
surface form:
western Indian Ocean
|
| typicalPropagationSpeed |
about 4 to 8 m/s
ⓘ
about 5 m/s ⓘ |
Referenced by (4)
Full triples — surface form annotated when it differs from this entity's canonical label.
this entity surface form:
MJO
this entity surface form:
Walker circulation