Modes of variability seen in OLR

Monitoring and Prediction of Modes of Coherent Tropical Variability

Real-time filtering of OLR data to monitor and predict the convective variations of the Madden-Julian oscillation and various convectively coupled equatorial waves, based on the "climatological" spectral peaks of a long record of satellite-observed data.

(Last updated with OLR data from: DD MNTH YEAR

)

Antisymmetric Modes		Symmetric Modes

*^^ Click on images to enlarge and obtain additional information. ^^*

Fig 1. Regions of wavenumber-frequency filtering for the outgoing longwave radiation (OLR) signals of certain modes of coherent tropical variability. These modes are identified as spectral peaks (the shading) in a wavenumber-frequency spectrum analysis of a long record of satellite-observed OLR, a good proxy for deep tropical convection. Filtering is for the Madden-Julian Oscillation (MJO; blue), Kelvin wave (green), n = 1 equatorial Rossby (ER) wave (black), and mixed Rossby-gravity (MRG) wave (brown). The so-called "convectively coupled equatorial waves" are defined to be in either the antisymmetric or symmetric components only, while the MJO is allowed to contain both components. For details, see Wheeler and Kiladis (1999, Journal of the Atmospheric Sciences).

The full details of the real-time filtering technique and testing of its skill have been provided in Wheeler and Weickmann (2001, Monthly Weather Review).

TIME-LONGITUDE PLOTS

Northern Tropics (2.5N-17.5N)

OLR Anomalies and All Modes: (last 6 months)
OLR Anomalies and MJO only: (last 6 months) or (last 2 years)

Near Equatorial (7.5S-7.5N)

OLR Anomalies and All Modes: (last 6 months)
OLR Anomalies and MJO only: (last 6 months) or (last 2 years)

Southern Tropics (17.5S-2.5S)

OLR Anomalies and All Modes: (last 6 months)
OLR Anomalies and MJO only: (last 6 months) or (last 2 years)

Wide Tropics (15.S-15.N)

OLR Anomalies and All Modes: (last 6 months)
OLR Anomalies and MJO only: (last 6 months) or (last 2 years)

FORECAST MAPS

MJO OLR Anomalies

5-day means (i.e., average of Days -4 to 0, 1 to 5, 6 to 10, etc.)
7-day means (i.e., average of Days -6 to 0, 1 to 7, etc.)

n=1 Equatorial Rossby OLR Anomalies

3-day means (i.e., average of Days -1 to 0, 1 to 2, etc.)
5-day means (i.e., average of Days -4 to 0, 1 to 5, etc.)

Kelvin wave OLR Anomalies

1-day means (i.e., maps of Days -2, 1, 0, 1, etc.)

MRG wave OLR Anomalies

1-day means (i.e., maps of Days -2, 1, 0, 1, etc.)

MAPS (ANIMATIONS)

MJO, n=1 ER, Kelvin, MRG

From Day-50 to Day+20 (i.e., up to 20-day forecast) Animated GIF or JAVA-script animation
From Day-20 to Day+10 (smaller files) Animated GIF or JAVA-script animation

MJO and Anoms only

From Day-80 to Day 0 (i.e., up to the present) Animated GIF or JAVA-script animation
From Day-30 to Day 0 (smaller files) Animated GIF or JAVA-script animation

Related Sites

An All-season Real-time Multivariate MJO Index
CAWCR's Current Climate Charts
Carl Schreck's tropical wave analysis

Created and maintained by Matthew Wheeler