The interaction between tropical clouds and radiation is studied in the context of weak temperature gradient approximation, using very low order systems (e.g., a two-column two-layer model) as zeroth-order approximation. Its criteria for instability are derived systems. Owing to connection (unstable fixed point) oscillation (limit cycle) physics (phase) space, suggest that leads atmospheric osc...

The seasonality of circumnavigation Madden–Julian Oscillation (MJO) events is examined using 42 years observations, reanalysis, and global model simulations. MJO are most likely to propagate across the Atlantic Ocean, Africa back equatorial Indian Ocean relatively unweakened during March–April–May a lesser extent September–October–November. During these seasons, referred as “long-rain” “short-r...

Abstract Based on the database of Subseasonal to Seasonal (S2S) Prediction project World Weather Research Programme (WWRP) / Climate (WCRP), influence North Atlantic Oscillation (NAO) Madden- Julian (MJO) and its forecast skill is investigated. It found that most models can capture MJO phase changes following positive negative NAO events. About 20 days after initialized with a (negative) NAO, a...

The impact of diurnal precipitation over Sumatra Island, the Indonesian Maritime Continent (MC), on synoptic disturbances eastern Indian Ocean is examined using high-resolution rainfall data from Global Satellite Mapping Precipitation project and Japanese 55-year Reanalysis during rainy season September to April for period 2000–2014. When cycle strong, high area observed in afternoon migrates o...

Title of Document: MADDEN-JULIAN OSCILLATION AND SEA SURFACE TEMPERATURE INTERACTIONS IN A MULTI-SCALE FRAMEWORK Lei Zhou, Ph. D., 2009 Directed By: Prof. Murtugudde, Department of Atmospheric and Oceanic Sciences/ESSIC The ocean-atmosphere coupling can play a role in initiating and sustaining the Madden-Julian Oscillations (MJOs), which are the major intraseasonal oscillations in the atmospher...

A probabilistic clustering method is used to describe various aspects of tropical cyclone (TC) tracks in the Southern Hemisphere, for the period 1969–2008. A total of 7 clusters are examined: three in the South Indian Ocean, three in the Australian Region, and one in the South Pacific Ocean. Large-scale environmental variables related to TC genesis in each cluster are explored, including sea su...

The effect of clouds on climate remains the largest uncertainty in climate change predictions, due to the inability of global climate models (GCMs) to resolve essential small-scale cloud and convection processes. We compare preindustrial and quadrupled CO2 simulations between a conventional GCM in which convection is parameterized and a "superparameterized" model in which convection is explicit...

This study examines the modulation of land-based extreme precipitation around globe by Madden-Julian Oscillation (MJO). The upper-level convergent phase MJO inhibits events over most regions but enhancement in other phases falls three categories. Over Brazil, Southeast Asia, and Australia, 2-year rainfall are common near core divergence as expected. For tropics subtropics, occur along periphery...

Abstract Recent observations have indicated significant modulation of the Madden Julian Oscillation (MJO) by phase stratospheric Quasi-Biennial (QBO) during boreal winter. Composites MJO show that upper tropospheric ice cloud fraction and water vapor anomalies are generally collocated, an eastward tilt with height in exists. Through radiative transfer calculations, it is shown clouds a stronger...