Wen-wen Tung

List of Publications

A. Book

B. Refereed journals


Tung’s research areas include two major themes:
      1) physical and stochastic characterizations and simulations of multiscale tropical convection/clouds and the two-way interactions between the cloud systems and the environmental atmosphere, and
      2) dynamical systems and the analysis of nonlinear and multiscale signals, with the purpose of simulating, predicting, and quantifying the dynamic predictability of observed systems.

These two areas are connected with each other, with 1) being rooted in traditional atmospheric sciences and 2) an interdisciplinary endeavor that can assist Tung to examine the underlying dynamics in 1).

1)   Multiscale Tropical Cloud/Convection Systems

Organized deep convection is known to intricately interact with larger-scale processes in the atmospheric general circulation through cloud microphysical processes and convective transports of heat, moisture, and momentum that greatly influence the weather and climate. General circulation model (GCM) inter-model comparisons have indicated that cloud feedbacks remain the primary source of uncertainty in determining Earth's equilibrium climate, as cloud processes are pivotal in the coupled land-ocean-atmosphere system by interacting with dynamical, chemical, hydrological, radiation, and boundary-layer processes. On the regional scales, biases in cloud-related fields may induce strong control on the local energy balance and ensuing responses.

Tropical deep convection represents a large fraction of global precipitation. The latent heat release associated with deep convection is an important component of the Earth's energy budget. The convection-coupled tropical variability exhibits multiscale characters across a wide range of scales in space and time as a result of the nonlinear and stochastic interactions among its component systems and hierarchical regulations imposed by the operating environment. For example, convective organizations over the Indian Ocean-Western Pacific warm pool appear to have spatial scales from O(100) to O(1000) km and temporal scales from O(1) to O(10) days. In other words, the observed organizations range from the mesoscale convective systems (MCSs) following the course of the diurnal cycle to organized super-cloud clusters embedded in the eastward-propagating planetary-scale, 20–90-day Madden-Julian oscillation (MJO).

The representations of the multiscale tropical clouds and convection in models have long been recognized as the critical barrier in weather and climate predictions. Failures of prediction in the tropics are known to corrupt predictions in higher latitudes through the pathways of planetary wave-trains and take a toll on the global society in extreme events and faulty policy-making. Therefore, the major motivation behind Tung’s research is to physically and/or mathematically characterize and simulate the multiscale tropical clouds/convective-coupled systems. Major topics in this area are:

Her method of inquisition has led her into collaborative interdisciplinary research in which she and collaborators have been developing general methods to quantify nonlinear dynamical systems with multiscale characteristics.

2)   Dynamical Systems and the Analysis of Nonlinear and Multiscale Signals

This aspect of Tung’s research started from her processing of the TOGA-COARE IOP station soundings and wind profiler data in 1998. Applications of the wavelet transform, FFT, structure function, and singular measure techniques to bring out the nonlinear and multiscale characteristics of the tropical convective variability in time have been documented in her work from 2002-2004. Perplexed by the complexity of the signals and systems being studied, troubled by the inadequacy of conventional physical and analytical approaches, and excited by the rich understanding obtained by systematically applying approaches based on dynamical systems theory and information theory, Tung has taken on a long (and non-ending) journey of interdisciplinary research with a core group of scientists of similar convictions, with the goal of creating a suite of nonlinear and multiscale signal analysis methods that can be used to solve a vast range of problems in science and engineering and have lasting values. The major topics in this area are:

'sky above, sky beneath, cloud self, water origin.' --- Dogen Kigen