Intraseasonal Variability in Earth’s Atmosphere and Ocean: The MISO and MJO

The Monsoon Intraseasonal Oscillation (MISO) is a process that occurs several times each year from May-October in the atmosphere over the tropical Indian Ocean, the western tropical Pacific Ocean, and the surrounding land areas. MISO events alternate between periods of wetter-than-average and drier-than-average conditions, a cycle that lasts longer than typical weather systems do (1-2 weeks), but shorter than a season (90 days). The way that the MISO affects rainfall and drought patterns is important to the economies and livelihoods of the people that live in South and Southeast Asia.

This animation shows the behavior of the MISO based on the average of many MISO events that occurred over a multi-year time period. The MISO events were visible with NASA and NOAA satellite sensors that measure outgoing longwave radiation (OLR), which is closely related to convection and its associated rainfall, as well as surface winds. Green colors show regions of higher-than-average rainfall, while brown colors show regions of lower-than-average rainfall. The day and phase counters show the progression of consecutive days and phases (positions) in the average 48-day cycle of the MISO.

The Monsoon Intraseasonal Oscillation (MISO) is a process that occurs several times each year from May-October in the atmosphere over the tropical Indian Ocean, the western tropical Pacific Ocean, and the surrounding land areas. MISO events alternate between periods of wetter-than-average and drier-than-average conditions, a cycle that lasts longer than typical weather systems do (1-2 weeks), but shorter than a season (90 days). The way that the MISO affects rainfall and drought patterns is important to the economies and livelihoods of the people that live in South and Southeast Asia.

This animation shows the close relationship between the ocean and atmosphere during the MISO based on the average of many MISO events that occurred over a multi-year time period. Enhanced rainfall (green) can be seen to lag behind warm sea surface temperatures (SSTs, red colors), which in turn lag behind reduced rainfall (brown) and cool SSTs (blue). Data are from the NASA Tropical Rainfall Measuring Mission (TRMM) satellite, using the entire 17-year operational lifetime of the satellite. The day and phase counters show the progression of consecutive days and phases (positions) in the average 48-day cycle of the MISO.

The Madden-Julian Oscillation (MJO) is a process that occurs several times each year from November-April in the atmosphere over the tropical Indian Ocean, the western tropical Pacific Ocean, and the surrounding land areas. MJO events alternate between periods of wetter-than-average and drier-than-average conditions, a cycle that lasts longer than typical weather systems do (1-2 weeks), but shorter than a season (90 days). The way that the MJO affects rainfall and drought patterns is important to the economies and livelihoods of the people that live in Southeast Asia, Indonesia, and Australia.

This animation shows the behavior of the MJO based on the average of many MJO events that occurred over a multi-year time period. The MJO events were visible with satellite sensors that measure outgoing longwave radiation (OLR), which is closely related to convection and its associated rainfall, as well as surface winds. Green colors show regions of higher-than-average rainfall, while brown colors show regions of lower-than-average rainfall. The day and phase counters show the progression of consecutive days and phases (positions) in the average 48-day cycle of the MJO.

The Madden-Julian Oscillation (MJO) is a process that occurs several times each year from November-April in the atmosphere over the tropical Indian Ocean, the western tropical Pacific Ocean, and the surrounding land areas. MJO events alternate between periods of wetter-than-average and drier-than-average conditions, a cycle that lasts longer than typical weather systems do (1-2 weeks), but shorter than a season (90 days). The way that the MJO affects rainfall and drought patterns is important to the economies and livelihoods of the people that live in Southeast Asia, Indonesia, and Australia.

This animation shows the close relationship between the ocean and atmosphere during the MJO based on the average of many MJO events that occurred over a multi-year time period. Enhanced rainfall (green) can be seen to lag behind warm sea surface temperatures (SSTs, red colors), which in turn lag behind reduced rainfall (brown) and cool SSTs (blue). Data are from the NASA Tropical Rainfall Measuring Mission (TRMM) satellite, using the entire 17-year operational lifetime of the satellite. The day and phase counters show the progression of consecutive days and phases (positions) in the average 48-day cycle of the MJO.