U.S. Department of Energy Office of Biological and Environmental Research

BER Research Highlights

Madden–Julian Oscillation Heating
Published: March 21, 2014
Posted: August 20, 2014

The Madden-Julian Oscillation (MJO) is a complex multiscale coupling between the large-scale atmospheric circulation and convection in the tropics that results in pulses of clouds and precipitation moving eastward at about 5 m/s. The MJO is the primary source of tropical variability on monthly time scales and also impacts weather outside the tropics, including North American winter precipitation. Global climate models (GCMs) have difficulty in accurately simulating the MJO, possibly because of GCM failure to adequately represent atmospheric heating associated with changes in the cloud populations. U.S. Department of Energy scientists used the Community Atmosphere Model version 4 (CAM4) to examine the relative importance of heating at different altitudes to the MJO. The results show that the MJO simulation is most sensitive to the existence of heating lower in the atmosphere ahead of the center of anomalous rainfall, while excess heating higher in the atmosphere degrades the MJO signal. The study also suggests that the standard CAM4 has difficulty simulating the MJO because it produces sufficient upper-level heating but not enough lower-level heating. Given that lower atmospheric heating was most important to producing an MJO signal, these results indicate that accurate shallow convective parameterizations may be more important than deep convective ones in simulating MJO evolution in GCMs.

Reference: Lappen, C., and C. Schumacher. 2014. "The Role of Tilted Heating in the Evolution of the MJO," Journal of Geophysical Research – Atmospheres 119(6), 2966–89. DOI:10.1002/2013JD020638. (Reference link)

Contact: Sally McFarlane, SC-23.1, (301) 903-0943, Ashley Williamson, SC-23.1, (301) 903-3120
Topic Areas:

  • Research Area: Earth and Environmental Systems Modeling
  • Research Area: Atmospheric System Research

Division: SC-23.1 Climate and Environmental Sciences Division, BER


BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER

Recent Highlights

May 10, 2019
Quantifying Decision Uncertainty in Water Management via a Coupled Agent-Based Model
Considering risk perception can improve the representation of human decision-making processes in age [more...]

May 09, 2019
Projecting Global Urban Area Growth Through 2100 Based on Historical Time Series Data and Future Scenarios
Study provides country-specific urban area growth models and the first dataset on country-level urba [more...]

May 05, 2019
Calibrating Building Energy Demand Models to Refine Long-Term Energy Planning
A new, flexible calibration approach improved model accuracy in capturing year-to-year changes in bu [more...]

May 03, 2019
Calibration and Uncertainty Analysis of Demeter for Better Downscaling of Global Land Use and Land Cover Projections
Researchers improved the Demeter model’s performance by calibrating key parameters and establi [more...]

Apr 22, 2019
Representation of U.S. Warm Temperature Extremes in Global Climate Model Ensembles
Representation of warm temperature events varies considerably among global climate models, which has [more...]

List all highlights (possible long download time)