A22E-07
The impact of diurnal cycle over the Maritime Continent on the Madden-Julian Oscillation
Tuesday, 15 December 2015: 11:50
3008 (Moscone West)
Samson M Hagos, Pacific Northwest National Laboratory, Richland, WA, United States, Chidong Zhang, Univ Miami-RSMAS/MPO, Miami, FL, United States, James J Benedict, Lawrence Berkeley National Laboratory, Berkeley, CA, United States, Charlotte A DeMott, Colorado State University, Atmospheric Science, Fort Collins, CO, United States and Zhe Feng, Joint Global Change Research Institute, College Park, MD, United States
Abstract:
The impact of diurnal cycle of convection processes over the Maritime Continent (MC) on the initiation and propagation of Madden-Julian Oscillation are examined using cloud permitting regional model simulations. A pair of control and no diurnal cycle simulations of the two MJO episodes observed during the 2011 AMIE/DYNAMO field campaign are performed. In the no diurnal cycle experiment the incoming shortwave radiation at the top of the atmosphere is maintained at its daily mean value. Without the diurnal cycle in solar forcing, convection over the MC is suppressed and the MJO signal over the Indian Ocean significantly weakens. Energy and moisture budget analysis shows diurnal cycle of convection over the MC provides a meridional moisture convergence over the Indian Ocean that is critical background condition for the initiation and eastward propagation of the MJO.
