Structure of the Madden–Julian Oscillation in the Superparameterized CAM
نویسندگان
چکیده
The detailed dynamic and thermodynamic space–time structures of the Madden–Julian oscillation (MJO) as simulated by the superparameterized Community Atmosphere Model version 3.0 (SP-CAM) are analyzed. Superparameterization involves substituting conventional boundary layer, moist convection, and cloud parameterizations with a configuration of cloud-resolving models (CRMs) embedded in each general circulation model (GCM) grid cell. Unlike most GCMs that implement conventional parameterizations, the SP-CAM displays robust atmospheric variability on intraseasonal space and time (30–60 days) scales. The authors examine a 19-yr SP-CAM simulation based on the Atmospheric Model Intercomparison Project protocol, forced by prescribed sea surface temperatures. Overall, the space–time structures of MJO convective disturbances are very well represented in the SP-CAM. Compared to observations, the model produces a similar vertical progression of increased moisture, warmth, and heating from the boundary layer to the upper troposphere as deep convection matures. Additionally, important advective and convective processes in the SP-CAM compare favorably with those in observations. A deficiency of the SP-CAM is that simulated convective intensity organized on intraseasonal space–time scales is overestimated, particularly in the west Pacific. These simulated convective biases are likely due to several factors including unrealistic boundary layer interactions, a lack of weakening of the simulated disturbance over the Maritime Continent, and mean state differences.
منابع مشابه
Response of the superparameterized Madden - Julian Oscillation to extreme climate and basic state variation challenges a moisture mode view
متن کامل
Investigating the Relationship between Drought with Teleconnection Patterns (Case Study: Qara Qom Basin)
Aims & Backgrounds: Drought is a natural feature of an area and in every region that occurs, it leads to economic, social and environmental losses. In this research, the Teleconnection patterns in drought occurrence in Qarh Qom basin has been investigated. Methodology: In this regard, precipitation data of 30 rain gauge and synoptic stations as well as data on 32 numerical indexes of teleconnec...
متن کاملThe Madden Julian Oscillation A Literature Review
The literature survey reviews our present understanding of the Madden Julian Oscillation. This perturbation to the circulation of the tropical atmosphere involves anomalies in climate elements such as pressure, wind, outgoing long wave radiation, and temperature. It is successfully simulated by the present generation of general climate and atmospheric general circulation models. The literature ...
متن کاملMJO Intensification with Warming in the Superparameterized CESM
The Madden–Julian oscillation (MJO) is the dominant mode of tropical intraseasonal variability, characterized by an eastward-propagating envelope of convective anomalies with a 30–70-day time scale. Here, the authors report changes in MJO activity across coupled simulations with a superparameterized version of the NCARCommunity Earth SystemModel. They find that intraseasonal OLR variance nearly...
متن کاملConvection in a Parameterized and Superparameterized Model and Its Role in the Representation of the MJO
The behavior of convection and the Madden–Julian oscillation (MJO) is compared in two simulations from the same global climate model but with two very different treatments of convection: one has a conventional parameterization of moist processes and the other replaces the parameterization with a two-dimensional cloud-resolving model, the so-called superparameterization. The different behavior o...
متن کامل