Global Climate Models and the Southeast Pacific
Scientists run Global Climate Models (GCMs) on fast supercomputers as a way to study Earth's climate. Scientists are constantly trying to make these models better so they can produce more accurate results. Climate is not the same everywhere in the world. There are some places where it is relatively easy to model the climate. There are other places where it is tricky to get realistic results from climate models. The Southeast Pacific, near the west coast of South America, is one of those tricky places!
Why is it so tricky to model the climate of the Southeast Pacific? Partly because there are a lot of connections between the land, ocean, and atmosphere in that area. Climate models have many different parts: the ocean, the clouds, the atmosphere's chemistry, and so on. In some places, these different systems influence each other a lot. That means the overall GCM only works well if the connections between parts of the model are good. It is challenging to get all of those relationships right in the Southeast Pacific.
The Southeast Pacific is also difficult to model because it is connected to other places around the globe. The occurrence of El Nino and La Nina are influenced by the climate of the Southeast Pacific. These events are also connected, however, to places in the Western Pacific thousands of kilometers away and even to phenomena that occur in the Atlantic Ocean. Climate model connections that span the globe are especially challenging for scientists to accurately describe and predict.
VOCALS scientists hope to improve modeling of the Southeast Pacific both to help with regional weather and climate forecasting and to improve Global Climate Models overall. They hope to better model cloud formation and rainfall patterns in the Southeast Pacific. They want to better understand how upwelling of cold ocean waters in coastal regions influences climate. They hope to get a better picture of the roles of aerosols in cloud formation, and they want to understand the extent to which different aerosols and low-level marine cumulus clouds reflect away incoming sunlight.