Heating experiments in CAM4 and the role of the background environment in MJO propagation

Heating experiments in CAM4 and the role of the background environment in MJO propagation-Poster Presentation

What environmental characteristics allow convection to organize on the scale of the Madden-Julian Oscillation (MJO)? What variables (moisture, temperature, winds etc.) critically determine the difference between MJO and non-MJO convection? Can we quantify these variables? These are some of the questions we hope to answer in this study. A modified version of the Community Atmospheric Model (CAM) 4.0 that can accept additional heating with fully interactive heating is used to produce large-scale convection in the model. We find that in some cases, the convection propagates eastward at MJO speeds. Variations in magnitude and the shape of the heating allow different 'flavors' of MJO to develop. More importantly, there is an upper limit to how much heating we can add to obtain these MJO like propagations. Also of interest is the finding that there are background atmospheres that do not allow the MJO-scale convection to take place, some environments even favor westward propagation. These atmospheres are studied in detail and attempts are made to qualitatively and quantitatively define an atmosphere that is favorable for MJO propagation just after initiation.