Environmental Science Models and Artificial Intelligence

Environmental science is one of the oldest scientific endeavors. Since the dawn of humanity, along with the ability to reason came the ability to observe and interpret the physical world. It is only natural that people would observe patterns then build basic mental models to predict a future state. For instance, records indicate that there has long been a version of the adage “Red at night, sailor's delight. Red in the morning, sailors take warning.”¹ This saying is a simple predictive model based on generations of experience, and it often works. Over time people noted relationships between observations of the sky and subsequent conditions, formed this mental model, and used it to predict future behavior of the weather (Fig. 1.1).

The age of enlightenment following the Renaissance brought a more modern approach to science. Careful experimentation and observation led to uncovering the physics underlying natural phenomena. For instance, a modern understanding of “Red at night, sailor's delight” is based on the theory of Mie scattering. Light rays are scattered by large dry dust particles to the west in the setting sun. According to this theory, large particles tend to scatter the longer wavelength red light forward more than they do the other frequencies of visible light. The long trajectory of the solar beams through the atmosphere when the sun is at a very low zenith angle (such as at sunset or sunrise) compounds this effect. Thus, when light rays from the setting sun are scattered by large dry dust particles associated with a high pressure system to the west, more red light reaches the observer, and the sky appears red. Since prevailing winds in the mid latitudes (where this adage is common) blow from west to east, more Mie scattering at dusk implies that a dry weather pattern is approaching. “Red in the morning, sailors take warning,” refers to a similar process at dawn when the low zenith angle in the east would produce more scattering associated with a high pressure system that has already passed, thus suggesting the possibility that a low pressure system is now approaching and wet weather may follow. This example exemplifies the types of physical explanations of observed phenomena that developed in the environmental sciences.