This project will conduct a series of experiments with a hierarchy of numerical models to improve understanding of the Madden-Julian Oscillation (MJO), a large-scale weather pattern that forms in the Indian Ocean and propagates slowly eastward into the central equatorial Pacific. The project is one component of the DYNAmics of the Madden-julian Oscillation (DYNAMO) field campaign, in which observations will be collected in the Indian Ocean from ships, islands, and aircraft between October 2011 and March 2012. The field campaign is a multi-agency effort with funding from NSF, the National Oceanic and Atmospheric Administration, the Department of Energy, and the Office of Naval Research, with international partiners including India, Japan, the Maldives, France, and several other countries.
The specific goals of this project are to test DYNAMO hypotheses on the roles of moistening processes and specific convective populations in MJO initiation, evaluate model performance, and provide feedback for model development. Specific tasks of the project are 1) to analyze the DYNAMO observations, both to test the DYNAMO hypotheses directly and to provide context and targets for further modeling efforts; 2) to perform and analyze hindcast experiments with global models that explicitly represent moist convection to augment DYNAMO observations in constraining the large-scale budgets and testing the roles of various processes in MJO initiation; 3) To compare observations with results from cloud-system-resolving models (CSRM) on limited domains, both forced in the traditional way using tendencies derived from the DYNAMO sounding array and in a more theoretical mode with forcing parameterized interactively; 4) to compare results from the limited domain CSRMs and single column models with convective parameterizations using the same forcing methods; and 5) To use results from the previous steps to improve and test a cumulus parameterization in a version of the NCAR global climate model. Specific DYNAMO observations to be used in the project include the temperature, moisture, and advective tendency profiles from the radiosonde network, radar observations, and an integrated surface flux dataset funded by the Office of Naval Research.
Motivation for this project and more generally for DYNAMO comes from the many ways in which the MJO affects weather and climate worldwide. The MJO regulates the active and break periods of the Asian and Australian monsoon systems, serves as a forcing agent for El Nino events, and, when it propagates into the Pacific ocean, impacts weather over the United States. MJO activity over the Pacific Ocean has a strong influence on hurricane formation in the Gulf of Mexico. Improved prediction of the MJO could thus allow long-lead forecasts (up to two weeks) of its worldwide weather and climate impacts, and research conducted under this project could serve as the basis for such advances in MJO prediction. In addition, this project will provide support and training to three graduate students and a postdoctoral fellow, thereby promoting the next generation of scientists in tropical meteorology and climatology. The project will also support a range of outreach activities including recruitment of minority students to graduate education in a STEM discipline, presentations in K-8 schools, and DYNAMO and MJO-themed activities at institution-wide outreach events at the supported institutions.
