Agriculture Impacts Weather: The Case for Connected Ecosystems
It’s fascinating to see how modern technology has helped us increase our agricultural productivity in areas not otherwise suited for our higher value crops, writes Brent Shaw on PrecisionAg.com. When viewing the Texas and Oklahoma Panhandles and southwest Kansas in Google Earth (see below), you can see areas of green interspersed with predominantly brown tones.
Zooming into any of these areas, you quickly discover that the vast majority of these green pixels are irrigated fields, drawing water up out of the ground from the Ogallala Aquifer, moistening the soil and the lower atmosphere via evapotranspiration that would not otherwise be occurring. Most of us have experienced micrometeorological effects due to small scale variations of the landscape, but with the much larger areas of landscape modification, visible enough to be readily identified from space, I am reminded of research by scientists such as Dr. Roger Pielke, Sr., postulating that landscape changes may be affecting climate regionally, perhaps much more significantly than any effect that atmospheric carbon dioxide content has had on a global scale.
Even as I was preparing this article, a press release came out discussing how a team of MIT scientists show evidence that Midwest summers have been cooler and wetter due to increased corn and soybean production. Just to get this on the record right away, I am not saying any of this is bad, good, or neutral. Our planet is an amazingly complex system of systems that are remarkably designed to interact and feedback with each other in more ways than we will ever understand in our lifetimes. We should apply what we have learned to feed a growing world more effectively while stewarding our most valuable resources such as water.
As one of Dr. Pielke’s graduate students in the early 1990s, I used numerical simulations of the atmosphere to determine whether or not variability of soil moisture and vegetation cover play a role in formation and evolution of Great Plains drylines, a type of weather front that frequently forms in the spring and summer days across this region, serving as a focal point for the formation of storms that provide a substantial portion of warm season rainfall as well as severe thunderstorms and tornadoes. Indeed, our simulations suggested that areas having high contrast in soil moisture conditions can enhance dryline strength and resulting local-scale circulations needed to initiate storms. My real interest in this area lies in whether or not we can improve our numerical weather prediction models, and thus our short and mid-term weather forecasts, through more accurate input information and improved physics algorithms. These models all use coupled Land Surface Models (LSMs) that account for heat and moisture transfer between the air, vegetation, and ground.