BYU research could improve accuracy of weather forecasts
If the only thing you hate more than an impossibly snarled commute is a weather forecast that's too late and too vague, a BYU professor has good news.
Assistant mechanical engineering professor Julie Crockett has figured out a way to improve weather predictions. Her research which was recently published in the International Journal of Geophysics looks at "atmospheric internal waves," which she said are similar to waves in an ocean. The waves move huge amounts of energy through the air and can significantly influence weather patterns, but typical weather forecasting models can't accurately track them, she said.
That's a problem, Crockett explained, because the waves can blow an anticipated snowstorm away earlier than predicted or enhance extreme weather events. That means people sometimes walk outside and see something completely different from what they heard on the evening weather forecast.
Crockett explained that people experience the waves when they feel turbulence on an airplane. The waves are constantly moving vertically and horizontally, crashing and cresting, and when a plane flies into their path the ride gets bumpy. The waves typically exist between layers of high- and low-density air and are very common, she added.
Lawrence Dunn, meteorologist in charge of the National Weather Service's Salt Lake City office, compared atmospheric waves to water movement at the beach. He said that the water gets pushed around by big swells, currents, wind and an array of other forces. The same thing goes on in the atmosphere, he said.
According to Dunn, weather forecasts today are very accurate: Sophisticated models and supercomputer technology have made eight-day forecasts as precise now as three-day forecasts were 20 or 30 years ago. Still, he said, experts can't input every possible atmospheric variable into their calculations, so an element of uncertainty remains.
"There is no way that we ever do know the exact state of the atmosphere," Dunn said.
Crockett's research aims to lessen that uncertainty. She said that while forecasters have taken into account atmospheric internal waves in the past, the new model she developed "adds complexity" and could facilitate an increasingly "large scale" approach to forecasting.
Crocket's research is based on experiments she did by producing waves in a tank in her lab. Crockett and her students tracked those waves and eventually were able to develop a model to describe their behavior. The results are the culmination of years of work.
"It's really exciting any time you accomplish something big," Crockett said, adding that she hopes it gets incorporated into actual weather predicting models in the future.