A Statistical/Stochastic Model of the Hydroclimate System

The hydroclimate system is a nonlinear, dynamic system with multiple feedbacks and interactions. The time evolution of this complex system seemingly defies deterministic description. An alternative model presented here considers the concept of a climate probability distribution function (climate pdf). The climate pdf is a probabilistic description of some element of the hydroclimate system that is based on the physics of the system. It can change with time and contains all physically possible outcomes for a given location. It can be estimated through the use of observations, Monte Carlo simulations, or through solution of a system of stochastic partial differential equations. Conditional climate pdfs associated with hydroclimate phenomena such as El Nino/Southern Oscillation (ENSO) can also be constructed. Climate pdfs and conditional climate pdfs can be used in hydrologic engineering applications. An overview of this statistical model of the hydroclimate system and an example application are presented in this paper.