The scientists used a computer model to study climate patterns from 1979 to 1994. They found that the model accurately represented pressure changes in the atmosphere, but didn't capture all aspects of El Niño events. The model showed connections between tropical sea temperatures and weather in the Northern Hemisphere. They discovered that the model's natural variability is greater than external influences, and at least five simulations are needed for accurate results. The model's ability to predict weather patterns in the Tropics and Northern Hemisphere is improved with more simulations.