MJO Teleconnections
The Madden-Julian Oscillation (MJO) is the leading pattern of intraseasonal variability in the tropics. It acts as a heat source, forcing large-scale waves known as Rossby waves that significantly alter the extratropical atmosphere. These Rossby waves connect remote regions of the world, and are therefore known as teleconnection patterns.
Figure: Average teleconnection pattern associated with MJO phase 3 during December - February. In the tropics, color shading shows the precipitation anomalies associated with MJO phase 3, defined when MJO precipitation is enhanced over the east Indian ocean and suppressed over the western Pacific.
The contours are composite 250-mb geopotential height anomalies using ERA-Interim reanalysis data from 1979-2014, with positive anomalies in red and negative anomalies in blue. Dotted regions indicate anomalies that are significantly different from zero at the 95% level. Adapted from Henderson et al. (2017) |
MJO teleconnections are associated with significant changes in global weather and climate patterns. These impacts have made the MJO an important source of predictability in weekly timescales.
MJO Teleconnections in General Circulation Models (GCMs)
Given the global influence of MJO teleconnections, it is important that they are well represented in GCMs. There are two primary factors that determine the characteristics of teleconnection patterns: 1) the mean background flow, also known as the basic state, and 2) the location and characteristics of the heat source, such as the MJO. However, the MJO has proven difficult to properly simulate in GCMs, and many models contain biases in the basic state.
In Henderson et al. (2017), we examined how well various GCMs reproduce MJO teleconnections, and more specifically the impact of the basic state and MJO representation on MJO teleconnection simulation.
Click here for the NOAA Model Diagnostics Task Force (MDTF) MJO Teleconnection Diagnostic Package
In Henderson et al. (2017), we examined how well various GCMs reproduce MJO teleconnections, and more specifically the impact of the basic state and MJO representation on MJO teleconnection simulation.
Click here for the NOAA Model Diagnostics Task Force (MDTF) MJO Teleconnection Diagnostic Package